JP5061394B2 - Surface coated cutting tool - Google Patents

Description

  The present invention relates to a surface-coated cutting tool in which a coating layer is formed on a substrate, and more particularly to a surface-coated cutting tool that has excellent stability at high temperatures and prolongs tool life by suppressing chipping of the blade edge.

  The base material of the surface-coated cutting tool is coated with various coating layers for the purpose of protecting the surface of the base material and further improving various properties such as wear resistance and toughness. It has been done for a long time. Recent trends in surface-coated cutting tools include the need for dry machining that does not require cutting fluids from the viewpoint of global environmental conservation, the diversification of work materials, and cutting speed to further improve machining efficiency. The cutting edge temperature of the surface-coated cutting tool at the time of cutting tends to be exposed to a higher temperature due to reasons such as higher feed rates and higher feed rates. As a result, since the tool life of the surface-coated cutting tool is shortened, the characteristics required for the material constituting the surface-coated cutting tool are becoming stricter.

  Therefore, in order to extend the life of the surface-coated cutting tool, the properties required for the material constituting the surface-coated cutting tool include the stability of the coating layer formed on the substrate at high temperatures (the oxidation resistance of the coating layer). Of course, the wear resistance and lubricity of the coating layer are also important.

  To improve the wear resistance of surface-coated cutting tools, a layer of TiAlN is laminated on a substrate such as WC-base cemented carbide, cermet, or high-speed steel to form a coating film It is well known to do. However, in recent high-speed machining and dry machining, a long-life surface-coated cutting tool cannot be obtained with a coating film made of only TiAlN.

  Therefore, in order to achieve a longer life of the surface-coated cutting tool, Patent Document 1 forms a coating layer containing Al, Cr, V, and N instead of the coating layer made of TiAlN that has been conventionally used. Thus, a surface-coated cutting tool having excellent stability at high temperatures is disclosed. However, the coating layer containing Al, Cr, V, and N has an effect in improving the stability at high temperature, but tends to have a large residual stress in the coating layer. In addition, there is a problem that the adhesiveness is inferior and the wear resistance or peel resistance is insufficient.

  Therefore, in order to further reduce the residual stress contained in the coating layer, for example, in Patent Document 2, an AlCrN layer containing Al, Cr and N and a TiAlSiN layer containing Ti, Al, Si and N are alternately laminated. A covering layer of a structured structure is disclosed.

JP 2003-34859 A International Publication No. 2006/070730 Pamphlet

  The surface-coated cutting tool disclosed in Patent Document 2 has almost solved the problem of the residual stress of the coating layer, but has the following new problem. That is, the covering layer composed of the alternating layers of the AlCrN layer and the TiAlSiN layer has a crystal structure in which each layer to be laminated has a columnar structure. Although the crystal structure of the coating layer tends to be refined compared with the case of forming with this layer, since the crystal structure of the coating layer has not yet been sufficiently refined, cracks generated in the coating layer during cutting work There was a problem that the progress could not be sufficiently suppressed, leading to chipping of the cutting edge, resulting in a decrease in the tool life of the surface-coated cutting tool.

  Therefore, in order to solve the problem of crack growth occurring in the coating layer, the crystal structure of each layer constituting the coating layer should be further refined under conditions where a higher load is applied to the surface-coated cutting tool. Is required.

  The present invention has been made in view of the situation as described above, and the object thereof is a surface that has excellent stability at high temperatures and prolongs tool life by suppressing chipping of the blade edge. It is to provide a coated cutting tool.

The surface-coated cutting tool of the present invention includes a base material and a coating layer formed on the surface of the base material, and the coating layer is formed by laminating one or more layers of A layers and B layers alternately. and comprises alternating layers, the layer a is viewed contains a and Al (aluminum) Cr and (chromium), a nitride which does not contain V, and Cr when the one the total number of metal atoms constituting the a layer is 0.4 or less larger than the atomic ratio of 0.05, B layer, viewed contains a Al (aluminum) and V (vanadium), a nitride which does not contain Cr, constituting the B layer metal The atomic ratio of V is 0.05 or more and 0.4 or less when the total number of atoms is 1.

  Here, the thickness of the A layer and the thickness of the B layer are each preferably larger than 1 nm and not larger than 200 nm.

  Further, it is preferable that the atomic ratio of Cr and the atomic ratio of V in the coating layer are substantially the same.

Further, the lowermost layer of the coating layer may be an A layer or a B layer.
In the alternating layers, the A layer and the B layer are laminated with the intermediate transition layer interposed therebetween, and the thickness of the composition of the intermediate transition layer is changed from the lower layer composition in contact with the intermediate transition layer to the upper layer composition in contact with the intermediate transition layer. It is preferable to change continuously in the direction.

  Moreover, it is preferable that the coating layer has an average residual stress of -8 GPa or more and 0 GPa or less.

  Moreover, it is preferable that the residual stress of the coating layer changes in the thickness direction of the coating layer, and the absolute value of the residual stress of the coating layer increases as the distance from the substrate increases.

The crystal structure of the coating layer is preferably cubic.
When the uppermost layer of the coating layer includes a C layer made of an oxide containing Al as a main component and containing at least one of Cr and V and Al, the total number of metal atoms constituting the C layer is It is preferable that the ratio of the total number of Cr and V when it is 1 is greater than 0 and 0.4 or less. Note that the “main component” in the C layer made of an oxide containing Al as a main component means that Al is the most contained in the metal constituting the C layer.

  The C layer further contains Y, and the ratio of the number of Y atoms when the total number of metal atoms constituting the C layer is 1 is preferably greater than 0.01 and 0.1 or less.

  ADVANTAGE OF THE INVENTION According to this invention, the surface-coated cutting tool which was excellent in stability at high temperature and the tool life was prolonged by suppressing chipping of the blade edge can be provided.

It is a typical expanded sectional view showing an example of the surface covering cutting tool of the present invention. It is a typical expanded sectional view which shows another example of the surface covering cutting tool of this invention. It is a typical side view of a cathode arc ion plating apparatus. FIG. 4 is a schematic top view of the cathode arc ion plating apparatus shown in FIG. 3. It is a typical expanded sectional view which shows another example of the surface covering cutting tool of this invention. It is a typical expanded sectional view which shows another example of the surface covering cutting tool of this invention. It is a typical top view of a cathode arc ion plating-sputtering composite apparatus.

  Hereinafter, the present invention will be described in more detail. In the following description of the embodiments, the description is made with reference to the drawings. In the drawings of the present application, the same reference numerals denote the same or corresponding parts.

<Surface coated cutting tool>
In FIG. 1, the typical expanded sectional view of an example of the surface coating cutting tool of this invention is shown. The surface-coated cutting tool 10 having the configuration shown in FIG. 1 includes a base material 5 and a coating layer including alternating layers 14 in which one or more A layers 12 and B layers 13 are alternately stacked on the surface of the base material 5. 11.

  FIG. 2 shows a schematic enlarged cross-sectional view of another example of the surface-coated cutting tool of the present invention. The surface-coated cutting tool 10 having the configuration shown in FIG. 2 includes a base material 5 and a coating layer including alternating layers 14 in which one or more B layers 13 and A layers 12 are alternately stacked on the surface of the base material 5. 11.

  Here, the surface-coated cutting tool 10 of the present invention having the base material 5 and the coating layer 11 as basic structures includes, for example, a drill, an end mill, a milling blade-tip-exchangeable cutting tip, a turning blade-tip-changing cutting tip, It can be used very effectively as a metal saw, gear cutting tool, reamer, tap, or pin milling tip for a crankshaft.

<Base material>
As the base material 5 of the surface-coated cutting tool 10 of the present invention, a conventionally known material known as a material of the base material 5 can be used without any particular limitation. For example, cemented carbide (for example, WC base cemented carbide, including WC, including Co, or further including carbonitride such as Ti, Ta, Nb, etc.), cermet (TiC, TiN, TiCN, etc.) High-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, and mixtures thereof), cubic boron nitride sintered body, diamond sintered body Etc. can be cited as examples of the substrate 5. In addition, when using a cemented carbide for the base material 5, the effect of this invention is shown even if the structure | tissue contains the abnormal phase called a free carbon and (eta) phase.

  The base material 5 may have a modified surface. For example, when a cemented carbide is used for the base material 5, a de-β layer may be formed on the surface of the base material 5, and when a cermet is used for the base material 5, a hardened layer is formed on the surface of the base material 5. Even if the surface of the base material 5 is modified, the effect of the present invention is exhibited.

<Coating layer>
The coating layer 11 formed on the surface of the base material 5 of the surface-coated cutting tool 10 of the present invention includes alternating layers 14 in which one or more A layers 12 and B layers 13 are alternately laminated. And The covering layer 11 constituting the surface-coated cutting tool 10 of the present invention may include other layers in addition to the alternating layers 14 as long as it includes the alternating layers 14 in which the A layers 12 and the B layers 13 are alternately stacked. Absent. Here, the lamination arrangement of the other layers is not particularly limited, and can be formed between the base material 5 and the alternating layer 14 and can also be formed on the alternating layer 14 or directly on the base material 5. Of course, it is also possible.

  The coating layer 11 constituting the surface-coated cutting tool 10 of the present invention is not limited to the one that covers the entire surface of the substrate 5, and includes a mode in which the coating layer 11 is not partially formed. In particular, a mode in which a part of the laminated structure of the coating layer 11 is different is also included.

  Moreover, it is preferable that the thickness of the coating layer 11 (total thickness of the coating layer 11) is 0.5 μm or more and 20 μm or less. When the total thickness of the coating layer 11 is less than 0.5 μm, the thickness of the coating layer 11 tends to be too thin and the tool life of the surface-coated cutting tool 10 tends to be shortened, and the thickness of the coating layer 11 exceeds 20 μm. At the initial stage of cutting, the coating layer 11 tends to chip and the tool life of the surface-coated cutting tool 10 tends to be shortened.

  Further, from the viewpoint of improving the tool life of the surface-coated cutting tool 10 and suppressing chipping of the coating layer 11, the upper limit of the thickness of the entire coating layer 11 is more preferably 15 μm or less, and even more preferably 8 μm or less. is there.

  Similarly, from the viewpoint of improving the tool life of the surface-coated cutting tool 10 and suppressing chipping of the coating layer 11, the lower limit of the thickness of the coating layer 11 is preferably 1 μm or more, more preferably 1 .5 μm or more.

  In the present invention, the thickness of the entire coating layer 11, the thickness of each layer described later, and the number of layers are all cut by the surface-coated cutting tool 10 of the present invention, and the cross section of the surface-coated cutting tool 10 is scanned by an electron microscope. It can be determined by observing using (SEM: Scanning Electron Microscope) or transmission electron microscope (TEM). Moreover, the composition of each layer which comprises the coating layer 11 can be measured using a X-ray photoelectron spectroscopy analyzer (XPS: X-ray photoelectron spectroscopy).

<Alternate layers>
In the present invention, the alternating layer 14 included in the coating layer 11 is one in which one or more A layers 12 and B layers 13 are alternately laminated, and the A layer 12 is a nitride containing Al and Cr. The ratio of the number of Cr atoms when the total number of metal atoms constituting the A layer 12 is 1 is greater than 0.05 and less than or equal to 0.4, and the B layer 13 includes Al and V. It is made of nitride and has a configuration in which the ratio of the number of V atoms is 0.05 or more and 0.4 or less when the total number of metal atoms constituting the B layer 13 is 1.

  Here, the alternating layer 14 is configured by alternately laminating the B layer 13 and the A layer 12 having a stress relaxation action, and thus the A layer 12 alone has a relatively large residual stress, and thus the base material 5. In addition, while suppressing the demerit that adhesion with other layers is inferior, it is possible to sufficiently exhibit the excellent operational effect of the A layer 12 that is superior in stability at high temperatures compared to conventional AlCrN, The stability at the time of high temperature at the time of cutting of the coated cutting tool 10 can be dramatically improved.

  In addition, by including the alternating layers 14 formed by alternately laminating the B layers 13 and the A layers 12 having the stress relaxation action (particularly, by sandwiching the A layers 12 between the two B layers 13), the A layers Accordingly, the coarsening of the crystal growth of 12 can be effectively prevented, and the crystal structure of the A layer 12 can be further refined. Further, since the B layer 13 is formed so as to be adjacent to the A layer 12 having a different composition, there is also an effect that the crystal growth of the B layer 13 itself can be prevented at the same time.

  In addition, by including the alternating layers 14 formed by alternately laminating the A layers 12 and the B layers 13, cracks generated on the surface of the coating layer 11 even under cutting conditions in which a high load is applied at a high temperature. The progress in the direction of the substrate 5 can be suppressed, and chipping of the cutting edge can be extremely effectively prevented. In particular, this point is a solution to the problem that the surface-coated cutting tool of Patent Document 2 as the prior art has, and has extremely large industrial applicability.

  Further, the inclusion of the alternating layers 14 formed by alternately laminating the A layers 12 and the B layers 13 suppresses the progress of cracks in the coating layer 11 probably due to the refinement of the crystal structure of the A layer 12. It is presumed that the crack generated on the surface of the coating layer 11 does not develop into large-scale delamination, but the progress of the crack is effectively blocked at the interface between the A layer 12 and the B layer 13. .

  The surface-coated cutting tool 10 of the present invention is excellent in stability at high temperatures and suppresses chipping of the blade edge, thereby providing wear resistance and fracture resistance even under cutting conditions where high loads are applied at high temperatures. Since a high degree of compatibility can be achieved, the tool life of the surface-coated cutting tool 10 can be extended.

  In the present invention, the number of stacked layers of the A layers 12 and the number of stacked layers of the B layers 13 included in the alternating layers 14 are the number of stacked layers of the A layers 12 and the B layers 13 constituting the alternating layers 14. Shall mean. For example, when the alternating layers 14 are configured by sequentially laminating the A layer 12, the B layer 13, the A layer 12, the B layer 13, and the A layer 12 in this order from the base material 5 side, The number of layers 12 is three, and the number of layers B 13 is two. Although the minimum number of layers of the A layer 12 and the B layer 13 is one for each of the A layer 12 and the B layer 13, the maximum number of layers of the A layer 12 and the B layer 13 is not particularly limited. The number of layers of each of the A layer 12 and the B layer 13 is preferably 10 or more and 5000 or less. When the number of layers of each of the A layer 12 and the B layer 13 is less than 10 respectively, the contribution to the refinement of the crystal structure in each layer tends to be small, and the layers of the A layer 12 and the B layer 13 are laminated. When the number exceeds 5000 layers, the thickness per layer becomes too thin and the A layer 12 and the B layer 13 tend to be mixed.

  Further, in the alternating layer 14 in the present invention, the lamination of the A layer 12 and the B layer 13 may be started from the A layer 12 as shown in FIG. 1, for example, and as shown in FIG. It may be started from. That is, in the alternating layer 14, the layer located closest to the substrate 5 side may be the A layer 12 or the B layer 13. Further, the stacking in the alternating layers 14 may end at the A layer 12 or may end at the B layer 13. That is, in the alternating layers 14, the layer farthest away from the substrate 5 side may be the A layer 12 or the B layer 13.

  Moreover, it is preferable that the thickness of the alternating layer 14 is 0.5 micrometer or more and 20 micrometers or less. When the thickness of the alternating layer 14 is less than 0.5 μm, the tool life of the surface-coated cutting tool 10 may be reduced, and when it exceeds 20 μm, the coating layer 11 itself is chipped due to a large residual stress. It tends to be easy to do.

  From the viewpoint of improving the tool life of the surface-coated cutting tool 10 and suppressing chipping of the coating layer 11, the upper limit of the thickness of the alternating layer 14 is more preferably 15 μm or less, and even more preferably 10 μm or less. .

  Similarly, from the viewpoint of improving the tool life of the surface-coated cutting tool 10 and suppressing chipping of the coating layer 11, the lower limit of the thickness of the alternating layer 14 is more preferably 1 μm or more, and even more preferably 1 .5 μm or more.

<A layer>
The A layers 12 in the alternating layers 14 are made of a nitride containing Al and Cr. However, since the A layers 12 contain Al, the temperature at which oxidation can be prevented becomes high (high acid resistance). ). In addition, since the A layer 12 contains not only Al but also Cr, the temperature at which oxidation can be prevented further increases (has high oxidation resistance). The A layer 12 may contain other elements as long as it contains Al, Cr, and N (nitrogen).

  The crystal structure of the A layer 12 is preferably cubic from the viewpoint of increasing the hardness of the A layer 12 and increasing the hardness of the coating layer 11. The crystal structure of AlN is usually hexagonal. However, when Cr is added to AlN, the crystal structure of AlN becomes cubic, so that the A layer 12 tends to have high hardness. The estimated lattice constant when AlN becomes a cubic crystal that is a metastable phase is 0.412 nm. On the other hand, the lattice constant of CrN, which is a stable phase of cubic crystals at room temperature and normal pressure, is 0.414 nm, which is very close to the estimated lattice constant of cubic AlN. Thus, the hardness of the A layer 12 can be increased.

  The effect of refining the crystal structure of the A layer 12 obtained by sandwiching the A layer 12 between the B layers 13 is exhibited even at high temperatures, so that the coating layer 11 exhibits sufficient high temperature stability. It will be a thing.

  The ratio of the number of Cr atoms when the total number of metal atoms constituting the A layer 12 is 1 is greater than 0.05 and less than or equal to 0.4. Here, when the ratio of the number of Cr atoms is 0.05 or less when the total number of metal atoms constituting the A layer 12 is 1, the effect of cubic crystallization of the crystal structure of AlN by Cr in the A layer 12 Tends to be not obtained, and when it is larger than 0.4, the hardness of the A layer 12 tends to decrease. Further, from the viewpoint of further increasing the hardness of the A layer 12, the ratio of the number of Cr atoms in the A layer 12 is preferably 0.2 or more and 0.35 or less, and is 0.25 or more and 0.3 or less. It is more preferable. In the present invention, the “metal atom” is hydrogen, helium, neon, argon, krypton, xenon, radon, fluorine, chlorine, bromine, iodine, astatine, oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus, arsenic, An atom of an element other than antimony and carbon.

  The ratio of the number of nitrogen atoms when the total number of metal atoms including Al and Cr in the A layer 12 is 1 is preferably 0.8 or more and 1.5 or less. When the ratio of the number of nitrogen atoms in the A layer 12 is less than 0.8, the hardness of the A layer 12 tends to decrease, and when the ratio of the number of nitrogen atoms in the A layer 12 exceeds 1.5 Similarly, the hardness of the A layer 12 tends to decrease.

<B layer>
The B layers 13 in the alternating layers 14 are made of a nitride containing Al and V, and may contain other elements as long as they contain Al, V, and N. If the B layer 13 is made of AlN not containing V, a strong oxide layer is formed on the outermost surface of the B layer 13, and the oxidation resistance of the B layer 13 is excellent at 1200 ° C. or higher. However, since the hardness of the B layer 13 is as extremely low as 20 to 25 GPa, the wear resistance tends to be lowered.

  Therefore, by making the B layer 13 a nitride containing Al and V, the structure of the crystal structure of the B layer 13 is refined to show a small residual stress value and exhibit an effect as a stress relaxation layer, while having a hardness of The hardness is increased to 40 to 45 GPa and high wear resistance is obtained. In addition, since the B layer 13 contains Al, the thermal conductivity of the B layer 13 is increased, and a heat dissipation effect that releases heat generated during cutting from the surface of the surface-coated cutting tool 10 to the atmosphere or through a machine tool is also obtained. It is done.

  When the B layer 13 contains V, the surface of the surface-coated cutting tool 10 tends to be heated at the time of cutting, and the surface of the coating layer 11 tends to be oxidized. However, since the oxide of V has a low melting point, Since it acts as a lubricant, it can be expected to suppress the adhesion of the work material to the coating layer 11.

  Moreover, although it is thought that it originates in the lubrication performance in the surface of the coating layer 11, since the B layer 13 can improve the welding resistance to the work material of the coating layer 11 by containing V, cutting The resistance can be reduced, and chip discharge can be improved.

  Here, the ratio of the number of V atoms when the total number of metal atoms constituting the B layer 13 is 1 is 0.05 or more and 0.4 or less. When the ratio of the number of V atoms is less than 0.05 when the total number of metal atoms constituting the B layer 13 is 1, the residual stress tends not to be sufficiently reduced. If it is larger than this, the hardness of the B layer 13 tends to decrease. From the viewpoint of further increasing the hardness of the B layer 13, the ratio of the number of V atoms when the total number of metal atoms constituting the B layer 13 is 1 is 0.2 or more and 0.35 or less. Preferably, it is 0.25 or more and 0.3 or less.

  The crystal structure of the B layer 13 is preferably cubic from the viewpoint of increasing the hardness of the B layer 13 and increasing the hardness of the coating layer 11. By making the ratio of the number of V atoms 0.05 to 0.4 when the total number of metal atoms constituting the B layer 13 is 1, a cubic Al compound that is a metastable phase at normal temperature and pressure And the hardness of the B layer 13 tends to be further improved. Note that the estimated lattice constant when AlN becomes a cubic crystal which is a metastable phase is 0.412 nm. On the other hand, the lattice constant of VN, which is a stable phase of cubic crystals at normal temperature and pressure, is 0.414 nm, which is very close to the estimated lattice constant of AlN of cubic crystals, and AlN is also crystallized by the pulling effect of V. As a result, the B layer 12 can be made harder.

  In the B layer 13, the ratio of the number of nitrogen atoms when the total number of metal atoms including Cr and V is 1 is preferably 0.8 or more and 1.5 or less. When the ratio of the number of nitrogen atoms when the total number of metal atoms in the B layer 13 is 1 is less than 0.8, the hardness of the B layer 13 tends to decrease. Similarly, the hardness of the B layer 13 tends to decrease.

<Examples of other elements contained in layer A or layer B>
In the present invention, the A layer 12 and / or the B layer 13 may contain boron in an atomic percent of less than 10 atomic percent. When the A layer 12 and / or the B layer 13 contain boron, the hardness of the A layer 12 and / or the B layer 13 tends to be further increased. Further, when the surface of the coating layer 11 is oxidized at a high temperature during cutting, the oxide of boron formed on the surface of the coating layer 11 is oxidized of Al contained in the A layer 12 and / or the B layer 13. It is also preferable because it tends to densify the object. Further, since the melting point of the boron oxide is as low as that of the V oxide, the boron oxide acts as a lubricant at the time of cutting at high temperature, and the covering layer 11 is welded to the work material. There is also a tendency to be able to suppress.

  In the present invention, the A layer 12 and / or the B layer 13 may contain Si in atomic percent and less than 10 atomic percent. When the A layer 12 and / or the B layer 13 contains Si, the hardness of the A layer 12 and / or the B layer 13 tends to be increased, and the crystal structure of the A layer 12 is refined, so that the There is also a tendency for the hardness to be further increased.

<Atom ratio other than Al of A layer and B layer>
The atomic ratio of Cr in the adjacent A layer 12 in the coating layer 11 (the atomic ratio of Cr when the total number of metal atoms constituting the A layer 12 is 1) and the atomic ratio of V in the B layer 13 ( It is preferable that the V atomic ratio (when the total number of metal atoms constituting the B layer 13 is 1) is substantially the same. The lattice constants of CrN and VN whose cubic crystal is a stable phase at normal temperature and normal pressure are both 0.414 nm, which is very close to the lattice constant of 0.412 nm of metastable cubic AlN. When the atomic ratio of V and the atomic ratio of V of the B layer 13 are substantially the same, the crystal lattice at the interface between the A layer 12 and the B layer 13 is continuous, and the A layer 12 and the B layer The strain due to the difference in lattice constant at the interface with the layer 13 can be reduced, the overall stress of the coating layer 11 can be reduced, and the adhesion between the A layer 12 and the B layer 13 can be improved. . “The atomic ratio of Cr in the A layer 12 and the atomic ratio of V in the B layer 13 are substantially the same” means that the atomic ratio of Cr in the A layer 12 and the B layer are determined by any analysis method. 13 includes the case where the atomic ratio of V is exactly the same, of course, there is a slight difference between the atomic ratio of Cr in the A layer 12 and the atomic ratio of V in the B layer 13 (A The case where the absolute value of the difference between the Cr atomic ratio of the layer 12 and the V atomic ratio of the B layer 13 is 3 or less) is also included.

<Thickness of A layer and B layer>
The thickness of the A layer 12 and the thickness of the B layer 13 are each preferably larger than 1 nm and not larger than 200 nm. By making both the A layer 12 and the B layer 13 have a thickness greater than 1 nm and not greater than 200 nm, the most effective suppression of the development of cracks (progress in the direction of the substrate) generated on the surface of the coating layer 11 is achieved. There is a tendency to be able to. In addition, when the thicknesses of the A layer 12 and the B layer 13 are each 1 nm or less, the effects of the A layer 12 and the B layer 13 being mixed and the A layer 12 and the B layer 13 being alternately stacked. It tends to be difficult to obtain, and when it exceeds 200 nm, it tends to be difficult to obtain the effect of suppressing the progress of cracks toward the base material 5.

  Further, from the viewpoint of sufficiently obtaining the effect of alternately laminating the A layer 12 and the B layer 13 and the effect of suppressing the progress of cracks in the direction of the base material 5, the thickness of the A layer 12 and the B layer 13 The thickness is more preferably 2 nm or more and 50 nm or less, and further preferably 4 nm or more and 30 nm or less.

  The thickness of the A layer 12 may be substantially the same for all the A layers 12 included in the alternating layers 14, and at least one of the A layers 12 may be another A layer. The thickness may be different from that of the layer 12. Also, regarding the B layer 13, substantially all of the B layers 13 may be the same in each of the B layers 13 included in the alternating layers 14, and the thickness of at least one layer of the B layers 13 may be other than that. The thickness may be different from that of the B layer 13.

<Intermediate transition layer>
In the alternating layer 14, the A layer 12 and the B layer 13 may be laminated with an intermediate transition layer (not shown) interposed therebetween, and the composition of the intermediate transition layer is intermediate from the composition of the lower layer in contact with the intermediate transition layer. It is preferable that the composition changes continuously in the thickness direction of the intermediate transition layer to the composition of the upper layer in contact with the transition layer. For example, in the alternating layer 14, when the layers are formed in the order of the A layer 12, the intermediate transition layer, and the B layer 13 from the base material 5 side, the composition of the intermediate transition layer is below the intermediate transition layer. (That is, the side in contact with the A layer 12) is the composition of the A layer 12, and is continuous from the composition of the A layer 12 to the composition of the B layer 13 in the thickness direction of the intermediate transition layer (the direction away from the substrate 5). Preferably, the upper side of the intermediate transition layer (that is, the side in contact with the B layer 13) is the composition of the B layer 13.

  As an aspect of the alternating layer 14 including the intermediate transition layer, for example, when stacking is started from the A layer 12, the intermediate transition layer is first formed on the A layer 12, and then the B layer 13 is formed on the intermediate transition layer. A layer in which an intermediate transition layer is formed on the B layer 13, an A layer 12 is formed on the intermediate transition layer, and an intermediate transition layer is subsequently formed between the A layer 12 and the B layer 13. The case where the alternating layer 14 is formed by repeating the embodiment is illustrated. In the present invention, even when an intermediate transition layer is formed between the A layer 12 and the B layer 13, the expression that the A layer 12 and the B layer 13 are alternately stacked is used. And

  The intermediate transition layer does not need to be formed independently of the A layer 12 and the B layer 13, and usually depends on the method of forming the coating layer 11, but usually when the B layer 13 is formed on the A layer 12 or B When the A layer 12 is formed on the layer 13, it may be unavoidably formed in the middle of the formation of the A layer 12 and the formation of the B layer 13. The intermediate transition layer may be a layer that is observed or not observed depending on the observation conditions, and is a layer that is usually observed when the observation magnification by TEM or the like is set to 2 million times or more. Also good.

  If the boundary between the A layer 12 and the B layer 13 cannot be clearly defined by forming the intermediate transition layer at the boundary between the A layer 12 and the B layer 13, The middle point in the thickness direction is regarded as the boundary between the A layer 12 and the B layer 13, and the thicknesses of the A layer 12 and the B layer 13 are measured.

<Lowermost layer of coating layer>
In the surface-coated cutting tool 10 according to the present invention, for example, as shown in FIG. Here, the lowest layer is a layer in the coating layer 11 that is in direct contact with the substrate 5. When the lowermost layer of the coating layer 11 is the A layer 12, even if the substrate 5 is exposed at the initial stage of cutting, oxidation from the interface between the substrate 5 and the coating layer 11 tends to be suppressed. It is in.

  For example, as shown in FIG. 2, the lowermost layer of the coating layer 11 can be a B layer 13. When the lowermost layer of the coating layer 11 is the B layer 13, since the B layer 13 tends to have a low stress, particularly in the case of intermittent processing such as milling or end milling in which a load is repeatedly applied to the cutting edge. The peel resistance of the coating layer 11 from the substrate 5 tends to be remarkably improved. In addition, as a lowermost layer of the coating layer 11, layers other than the A layer 12 and the B layer 13 may be formed.

<Top layer of coating layer>
In the formation of the coating layer 11 of the surface-coated cutting tool 10 of the present invention, a C layer may be formed as the uppermost layer of the coating layer 11. By including the C layer as the uppermost layer of the coating layer 11, the friction coefficient of the coating layer 11 can be reduced and oxidation resistance can be imparted to the coating layer 11. Here, the C layer is made of carbonitride (compound containing carbon and nitrogen) containing at least one metal selected from the group consisting of Al, B (boron), Cr and V, and the metal constituting the C layer The ratio of the number of Al atoms and / or the ratio of the number of V atoms when the total number of atoms is 1 is preferably 0.05 or more and 0.4 or less. In the surface-coated cutting tool 10 of the present invention, the uppermost layer of the coating layer 11 is a layer constituting the outermost surface of the coating layer 11, and the uppermost layer can be formed on the alternating layers 14.

  The uppermost layer of the coating layer 11 has the highest temperature as compared with the surface of the other layers during the cutting process, but the uppermost layer includes the C layer, thereby extremely effectively preventing the coating layer 11 from being oxidized. In addition, since the friction coefficient of the coating layer 11 against the work material decreases, the surface-coated cutting tool 10 tends to have a long life. In general, the friction coefficient tends to be reduced by containing carbon atoms, and the metal carbonitride tends to have a lower friction coefficient of the coating layer 11 against the work material than the metal nitride. It is preferably composed of a metal carbonitride containing at least one selected from the group consisting of Al, B, Cr and V.

  Moreover, it is preferable that the thickness of C layer is 0.1 micrometer or more and 2 micrometers or less. When the thickness of the C layer is less than 0.1 μm, the effect of extending the life of the surface-coated cutting tool 10 by imparting the lubricity of the outermost surface of the coating layer 11 tends to be difficult to be obtained. When it exceeds 2 μm, the effect of extending the life of the surface-coated cutting tool 10 tends not to be further improved.

  Further, it is possible to impart a predetermined color to the surface of the surface-coated cutting tool 10 by adjusting the atomic ratio of nitrogen and the atomic ratio of carbon contained in the C layer. Thereby, since designability can be provided to the appearance of the surface-coated cutting tool 10, it is commercially useful. The atomic ratio of nitrogen and carbon is not particularly limited, but the atomic ratio of carbon when the total number of nitrogen atoms and carbon atoms in the C layer is 1. Is preferably 0.05 or more and 0.6 or less. If the carbon atom ratio in the C layer is less than 0.05, the effect of imparting lubricity tends not to be obtained, and if it exceeds 0.6, the hardness of the C layer increases. The coating layer 11 itself tends to be easily chipped.

  The uppermost C layer of the covering layer 11 is made of an oxide containing Al as a main component and containing at least one of Cr and V and Al, and the total number of metal atoms constituting the C layer is 1. It is preferable to use a layer in which the ratio of the total number of Cr and V is greater than 0 and not greater than 0.4. When a C layer made of an oxide containing Al as a main component and containing at least one of Cr and V and Al is used as the uppermost C layer of the coating layer 11, an oxide containing Al as a main component The effect of the substitution of Cr and / or V and Al contained therein improves the crystallinity of the C layer made of the above-mentioned oxide containing Al as a main component, and also improves the above-mentioned oxide containing the main component of Al. The surface is obtained by improving the welding resistance of the coating layer 11 to the work material and the oxidation resistance of the coating layer 11 during cutting of the surface-coated cutting tool by the oxide of Cr and / or the oxide of V in the C layer. The coated cutting tool 10 tends to have a long life.

  Oxides containing Al as the main component are superior in stability of crystal structure and characteristics at high temperatures compared to nitrides and carbonitrides containing the same Al as the main component, and the reaction with the work material is suppressed. It is considered that the welding resistance of the coating layer 11 to the work material is improved. In addition, when the surface-coated cutting tool is cut, the surface of the C layer composed of the oxide mainly composed of Al is the highest temperature in the oxidizing atmosphere as compared with the other layers in the coating layer 11, Since an oxide containing Al as a main component is superior in oxidation resistance at a high temperature as compared with a nitride or carbonitride containing the same Al as a main component, the oxidation resistance of the coating layer 11 is improved.

  Moreover, it is preferable that the thickness of the C layer made of an oxide mainly containing Al containing at least one of Cr and V and Al is 0.1 μm or more and 4 μm or less. When the thickness of the C layer made of an oxide containing Al as a main component is less than 0.1 μm, the effect of prolonging the life of the surface-coated cutting tool 10 by imparting the lubricity of the outermost surface of the coating layer 11 is achieved. When the thickness of the C layer made of the above oxide containing Al as a main component is more than 4 μm, the adhesion of the coating layer 11 to the base material 5 is reduced, and the above Al is the main component. There is a tendency that the effect of forming the C layer made of the oxide is not sufficiently exhibited.

  Further, the crystal structure of the C layer made of an oxide containing Al as a main component and containing at least one of Cr and V and Al is any one of α-alumina type, γ-alumina type, or a structure in which these are mixed. It is preferable that Further, at least a part of the C layer made of an oxide containing Al containing at least one of Cr and V and Al may have an amorphous structure. The most stable crystal structure of the C layer made of an oxide containing Al as a main component at a high temperature is α-alumina type. However, if the C layer made of an oxide containing Al as a main component is γ- Even in the case of having an alumina type crystal structure and / or an amorphous structure, cutting performance at a high temperature is improved as compared with a nitride or carbonitride containing the same Al as a main component. This is because, even when the coating layer 11 becomes high temperature during the cutting of the surface-coated cutting tool 10, the above-mentioned C layer made of an oxide mainly composed of Al is an oxide, so This is because the oxidation can be suppressed, and the oxidation of the base material 5 and the layer between the base material 5 and the C layer composed of the above-described oxide containing Al as a main component can be suppressed.

  Further, the C layer made of an oxide containing Al as a main component and containing at least one of Cr and V and Al further constitutes a C layer made of an oxide containing Al as a main component. From the viewpoint of further improving the cutting performance, it is preferable that the ratio of the number of Y atoms when the total number of metal atoms is 1 is greater than 0.01 and not greater than 0.1. When Y is contained in the above-mentioned C layer made of an oxide containing Al as a main component, the oxide of Y precipitates at the crystal grain boundary of the oxide containing Al as the main component, and oxygen grain boundary diffusion Therefore, the oxidation of the base material 5 tends to be remarkably reduced. Thereby, it exists in the tendency which can further extend the lifetime of the surface coating cutting tool 10 in the continuous turning in which cutting edge temperature becomes high, or the milling with comparatively small load.

  In the surface-coated cutting tool 10 of the present invention, for example, as shown in FIG. 5, the uppermost layer of the coating layer 11 can be a C layer 15 and the lowermost layer can be an A layer 12. For example, as shown in FIG. 6, the uppermost layer of the coating layer 11 can be a C layer 15, and the lowermost layer of the coating layer 11 can be a B layer 13. However, the structure in the case where the uppermost layer of the coating layer 11 of the surface-coated cutting tool 10 of the present invention is the C layer 15 is not limited to the structure shown in FIGS. 5 and 6.

<Residual stress of coating layer>
The coating layer 11 constituting the surface-coated cutting tool 10 of the present invention preferably has an average residual stress of −8 GPa or more and 0 GPa or less. That is, when the residual stress of the coating layer 11 is averaged, it is preferably an average residual stress of −8 GPa or more and 0 GPa or less, and may be a case where the stress is released for convenience and the coating layer 11 has no residual stress. . Since the coating layer 11 has an average residual stress of −8 GPa or more and 0 GPa or less, it is possible to suppress the occurrence of chipping in the coating layer 11, and thus the reliability of the cutting edge of the surface-coated cutting tool 10 of the present invention is improved. In addition, the tool life of the surface-coated cutting tool 10 can be extended.

  From the viewpoint of extending the tool life of the surface-coated cutting tool 10, the average residual stress of the coating layer 11 is preferably −5 GPa or more and −0.5 GPa or less, and −3 GPa or more and −0.5 GPa or less. More preferably.

  When the average residual stress of the coating layer 11 exceeds 0 GPa and has a “positive” value, it becomes a tensile residual stress, so that it is difficult to suppress the development of cracks generated on the surface of the coating layer 11 in the direction of the base material 5. Tend. On the other hand, when the average residual stress of the coating layer 11 is less than −8 GPa, the compressive residual stress is too large (that is, the absolute value of the average residual stress is too large), and the edge portion of the surface-coated cutting tool 10 is started before cutting. Therefore, the coating layer 11 is peeled off and the tool life of the surface-coated cutting tool 10 tends to be shortened. In the present invention, the average residual stress of the coating layer 11 is an average value of the residual stress of the entire coating layer 11. In the present specification, when the description of compressive residual stress and a numerical value are written together, the numerical value is written without a minus sign.

Further, the average residual stress of the coating layer 11 changes in the thickness direction of the coating layer 11 from the viewpoint of more effectively suppressing the development of cracks generated on the surface of the coating layer 11 toward the base material 5 side. It is preferable that the absolute value of the average residual stress increases as the distance from the material 5 increases (that is, the compressive residual stress increases). In the present invention, the average residual stress of the coating layer 11 can be measured by the sin ² ψ method using an X-ray stress measuring apparatus.

<Crystal structure of coating layer>
The crystal structure of the coating layer 11 constituting the surface-coated cutting tool 10 of the present invention is preferably a cubic crystal. When the crystal structure of the coating layer 11 is a cubic crystal, the hardness of the coating layer 11 tends to be improved. For example, taking AlN as a nitride as an example, AlN is usually a hexagonal crystal, but the lattice constant in the case of a cubic crystal that is a metastable phase is 0.412 nm, whereas normal temperature and normal pressure. In addition, the lattice constant of CrN and VN in which cubic crystal is a stable phase is 0.414 nm, and since the lattice constant is very close to cubic AlN, AlN is cubically crystallized due to the pulling effect of Cr or V to increase the hardness. To do. For this reason, the A layer 12 can be a cubic crystal by using a nitride containing Al and Cr or V.

  In this way, by making each crystal structure of the A layer 12 and / or the B layer 13 included in the coating layer 11 cubic, the surface coating cutting with improved hardness and excellent wear resistance of the coating layer 11. The tool 10 can be used. The crystal structures of the coating layer 11 and the A layer 12 and the B layer 13 in the coating layer 11 can be analyzed by an X-ray diffractometer known in the art.

<Manufacturing method>
In the surface-coated cutting tool 10 of the present invention, for example, one or more layers of the A layer 12 and the B layer 13 are alternately laminated on the substrate 5 by using the process of preparing the substrate 5 and physical vapor deposition. And the step of forming the alternating layers 14. Here, in order to form the alternating layers 14 having wear resistance on the surface of the substrate 5, it is preferable to form a layer made of a compound having high crystallinity. Therefore, as a result of examining various methods as a method for forming the alternating layers 14, it has been found that it is preferable to use a physical vapor deposition method.

  As the physical vapor deposition method, for example, at least one selected from the group consisting of a cathode arc ion plating method, a balanced magnetron sputtering method, and an unbalanced magnetron sputtering method can be used. Note that layers other than the alternating layers 14 as the covering layer 11 can also be formed, for example, by physical vapor deposition.

  Here, as a physical vapor deposition method, it is preferable to use a cathode arc ion plating method. When the cathodic arc ion plating method is used as the physical vapor deposition method, it is possible to perform metal ion bombardment treatment on the surface of the base material 5 before forming the coating layer 11. Adhesiveness with the coating layer 11 can be significantly improved. Further, the cathode arc ion plating method has an advantage that the ionization rate of the raw material elements is high.

  Here, in the cathode arc ion plating method, for example, after the base material 5 is installed in the cathode arc ion plating apparatus and the target is installed as the cathode, a high current is applied to the target to cause arc discharge. Stacking can be performed by evaporating and ionizing atoms constituting the target and depositing a substance on the substrate 5.

  In addition, the balanced magnetron sputtering method, for example, sets the base 5 in the apparatus and sets the target on the magnetron electrode provided with a magnet that forms a balanced magnetic field, and then, between the magnetron electrode and the base 5. A gas plasma is generated by applying a high frequency power to the gas, and ions of the gas generated by the generation of the gas plasma collide with the target to ionize the atoms emitted from the target and deposit them on the substrate 5. Can do.

  Further, the unbalanced magnetron sputtering method can be performed, for example, by making the magnetic field generated by the magnetron electrode in the balanced magnetron sputtering method non-equilibrium.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. The surface-coated cutting tools of Examples 1 to 16 and Comparative Examples 1 to 4 were produced as follows, and the tool life of each surface-coated cutting tool was evaluated.

  Table 1 shows the configuration of the coating layer of each surface-coated cutting tool of Examples 1 to 16 and Comparative Examples 1 to 4, and Table 2 shows the characteristics (hardness and compressive residual stress) and crystal of the coating layer of the surface-coated cutting tool. The structure is shown. Table 3 shows the evaluation results of the tool life when the intermittent cutting test and the strong intermittent cutting test were performed on the surface-coated cutting tools of Examples 1 to 16 and Comparative Examples 1 to 4. Table 4 shows cutting conditions (work material, cutting speed vc, feed fz, and cutting ap) of the intermittent cutting test and the strong intermittent cutting test.

Example 1
FIG. 3 shows a schematic side view of the cathode arc ion plating apparatus, and FIG. 4 shows a schematic top view of the cathode arc ion plating apparatus 30 shown in FIG.

  As shown in FIG. 3, the cathode arc ion plating apparatus 30 includes an A layer cathode 6, a B layer cathode 7, and a base material 5, which are alloy targets serving as metal raw materials for the coating layer in the chamber 1. And a rotary base material holder 4 for installing the device. An arc power source 8 is attached to the A layer cathode 6, and an arc power source 9 is attached to the B layer cathode 7. A bias power source 20 is attached to the rotary base material holder 4. In addition, a gas introduction port 2 through which gas is introduced is provided in the chamber 1, and a gas discharge port 3 is provided to adjust the pressure in the chamber 1, and the chamber 1 is discharged from the gas discharge port 3 by a vacuum pump. The internal gas is sucked to adjust the pressure in the chamber 1.

  Below, the manufacturing method of the surface coating cutting tool of Example 1 is demonstrated. First, as shown in FIG. 3, a base material 5 having a grade of JIS standard P20 cemented carbide and having a shape of SDKN42MT was mounted on the rotary base material holder 4 of the cathode arc ion plating apparatus 30.

Then, an Al _0.65 Cr _0.35 target was set on the A layer cathode 6, and an Al _0.7 V _0.3 target was set on the B layer cathode 7. Then, while the pressure inside the chamber 1 is reduced by a vacuum pump, the temperature is heated to 600 ° C. by a heater installed in the chamber 1 of the cathode arc ion plating apparatus 30 while rotating the substrate 5, and the pressure in the chamber 1 is increased. Was evacuated until the pressure became 1.0 × 10 ⁻⁴ Pa.

  Next, Ar gas is introduced from the gas introduction port 2 to maintain the pressure in the chamber 1 at 3.0 Pa, and while gradually increasing the voltage of the bias power source 20 to −1000 V, the surface of the substrate 5 is cleaned by 30. For a minute. Thereafter, the argon gas was exhausted from the chamber 1 and the surface of the substrate 5 was cleaned by sputtering.

Next, with the base material 5 rotated at the center, the temperature of the base material 5 was set to 600 ° C. and the reaction gas pressure was set to 2.0 Pa while introducing nitrogen as a reaction gas from the gas inlet 2. In the above, while maintaining the voltage of the bias power source 20 at a certain constant value in the range of −50 V to −400 V or gradually changing the voltage, an arc current of 100 A is supplied to the A layer cathode 6 and the B layer cathode 7 respectively. Thus, metal ions were generated from the A layer cathode 6 and the B layer cathode 7 by arc discharge, and an A layer made of an Al _0.65 Cr _0.35 N layer having a thickness of 0.006 μm was first formed on the substrate 5. Later, a B layer composed of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm was formed, and thereafter, the A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer was Al _0.65 Cr _0.35 N Layer Consisting of a layer A). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  By the above, the coating layer which consists of an alternating layer of A layer and B layer was formed, and the surface coating cutting tool (blade tip exchange type cutting tip) of Example 1 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 1 was observed by SEM, it was confirmed that the thickness of the entire coating layer (total thickness) was 3.6 μm.

(Example 2)
The base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.75 Cr _0.25 target is set on the A layer cathode 6, and Al _0.8 is set on the B layer cathode 7. A V _0.2 target was set.

Then, an A layer composed of an Al _0.75 Cr _0.25 N layer having a thickness of 0.006 μm is first formed on the substrate, and then a B layer composed of an Al _0.8 V _0.2 N layer having a thickness of 0.006 μm is formed. The A layer and the B layer were alternately stacked one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.75 Cr _0.25 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 2 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 2 was observed by SEM, it was confirmed that the thickness of the entire coating layer (total thickness) was 3.6 μm.

(Example 3)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.9 Cr _0.1 target is set on the A layer cathode 6, and Al _0.85 is set on the B layer cathode 7. V _0.15 target was set.

Then, an A layer made of an Al _0.9 Cr _0.1 N layer having a thickness of 0.006 μm is formed on the substrate, and then a B layer made of an Al _0.85 V _0.15 N layer having a thickness of 0.006 μm is formed. The A layer and the B layer were alternately stacked one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.9 Cr _0.1 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 3 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 3 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 3.6 μm.

(Example 4)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.002 μm is first formed on the substrate, and then an A layer made of an Al _0.65 Cr _0.35 N layer having a thickness of 0.002 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 500 (total thickness of layer A: 1.0 μm, total thickness of layer B: 1.0 μm), cathode A for layer 6 and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-exchangeable cutting tip) of Example 4 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 4 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 2.0 μm.

(Example 5)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.015 μm is first formed on the substrate, and then an A layer made of an Al _0.65 Cr _0.35 N layer having a thickness of 0.015 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 150 (total thickness of layer A: 2.3 μm, total thickness of layer B: 2.3 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 5 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 5 was observed with an SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 4.6 μm.

(Example 6)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.05 μm is formed on the substrate, and then an A layer made of an Al _0.65 Cr _0.35 N layer having a thickness of 0.05 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 50 (total thickness of layer A: 2.5 μm, total thickness of layer B: 2.5 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 6 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 6 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 5.0 μm.

(Example 7)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.15 μm is first formed on the substrate, and then an A layer made of an Al _0.65 Cr _0.35 N layer having a thickness of 0.15 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 10 (total thickness of layer A: 1.5 μm, total thickness of layer B: 1.5 μm), cathode A for layer 6 and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 7 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 7 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 3.0 μm.

(Example 8)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, an A layer composed of an Al _0.65 Cr _0.35 N layer having a thickness of 0.006 μm is formed on the substrate, and then a B layer composed of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm is formed. The A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.65 Cr _0.35 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 80 (total thickness of layer A: 0.5 μm, total thickness of layer B: 0.5 μm), cathode A 6 for layer A and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-exchangeable cutting tip) of Example 8 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 8 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 1.0 μm.

Example 9
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, an A layer composed of an Al _0.65 Cr _0.35 N layer having a thickness of 0.006 μm is formed on the substrate, and then a B layer composed of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm is formed. The A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.65 Cr _0.35 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  Then, when the number of layers A and B is 600 (total thickness of layer A: 3.6 μm, total thickness of layer B: 3.6 μm), cathode A for layer 6 and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 9 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 9 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 7.2 μm.

(Example 10)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.35 target is set on the A layer cathode 6, and Al _0.7 is set on the B layer cathode 7. A V _0.3 target was set.

Then, an A layer composed of an Al _0.65 Cr _0.35 N layer having a thickness of 0.006 μm is formed on the substrate, and then a B layer composed of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm is formed. The A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.65 Cr _0.35 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  Then, when the number of layers A and B is 1500 (total thickness of layer A: 9.0 μm, total thickness of layer B: 9.0 μm), the cathode 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and the surface-coated cutting tool (blade-replaceable cutting tip) of Example 10 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 10 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 18.0 μm.

(Example 11)
With sets substrate 5 to a rotary substrate holder 4 of the cathode arc ion plating loading apparatus 30 shown in FIG. 3, to set the Al _0.7 Cr _0.3 target A layer for cathode 6, Al _0.7 to B layer for a cathode 7 A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm is first formed on the substrate, and then an A layer made of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of laminated layers A and B is 350 (total thickness of layer A: 2.1 μm, total thickness of layer B: 2.1 μm), cathode A 6 for layer A and layer B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 11 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 11 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 4.2 μm.

(Example 12)
With sets substrate 5 to a rotary substrate holder 4 of the cathode arc ion plating loading apparatus 30 shown in FIG. 3, to set the Al _0.7 Cr _0.3 target A layer for cathode 6, Al _0.7 to B layer for a cathode 7 A V _0.3 target was set.

Then, a B layer made of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm is first formed on the substrate, and then an A layer made of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm is formed. The B layer and the A layer were alternately stacked one by one in this order (that is, the lowermost layer is a B layer made of an Al _0.7 V _0.3 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of laminated layers A and B is 350 (total thickness of layer A: 2.1 μm, total thickness of layer B: 2.1 μm), cathode A 6 for layer A and layer B The current supplied to the layer cathode 7 was once stopped.

Thereafter, after the gas in the cathode arc ion plating apparatus 30 is once exhausted, a temperature of the base material 5 is set to 400 ° C. and a reaction gas pressure is set while introducing a mixed gas of nitrogen and methane as a reaction gas into the chamber 1. By supplying an arc current of 100 A to the B layer cathode 7 while maintaining the voltage of the bias power supply 20 at −350 V at 2.0 Pa, metal ions are generated from the B layer cathode 7, and 0.5 μm An uppermost layer composed of an Al _0.7 V _0.3 C _0.4 N _0.6 layer having a thickness was formed. Then, the current supplied to the bias power source 20 was stopped after the uppermost layer was formed.

  Except for the above, in the same manner as in Example 1, a coating layer composed of alternating layers of A and B layers and the uppermost layer was formed, and the surface-coated cutting tool (blade-replaceable cutting tip) of Example 12 was formed. Produced. When the cross section of the coating layer of the surface-coated cutting tool of Example 12 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 4.7 μm.

(Example 13)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.3 Si _0.05 target is set on the A layer cathode 6, and the B layer cathode 7 is set. An Al _0.65 V _0.3 Si _0.05 target was set.

Then, an A layer made of an Al _0.65 Cr _0.3 Si _0.05 N layer having a thickness of 0.006 μm is first formed on the substrate, and then a B layer made of an Al _0.65 V _0.3 Si _0.05 N layer having a thickness of 0.006 μm. After that, the A layer and the B layer were alternately stacked one by one in this order (that is, the lowermost layer is an A layer made of an Al _0.65 Cr _0.3 Si _0.05 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 13 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 13 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 3.6 μm.

(Example 14)
A base material 5 is set on the rotary base material holder 4 of the cathode arc ion-plating apparatus 30 shown in FIG. 3, an Al _0.65 Cr _0.3 B _0.05 target is set on the A layer cathode 6, and the B layer cathode 7 is set. An Al _0.65 V _0.3 B _0.05 target was set.

Then, an A layer composed of an Al _0.65 Cr _0.3 B _0.05 N layer having a thickness of 0.006 μm is first formed on the substrate, and then a B layer composed of an Al _0.65 V _0.3 B _0.05 N layer having a thickness of 0.006 μm is formed. After that, the A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.65 Cr _0.3 B _0.05 N layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was once stopped.

Thereafter, after the gas in the cathode arc ion plating apparatus 30 is once exhausted, a temperature of the base material 5 is set to 400 ° C. and a reaction gas pressure is set while introducing a mixed gas of nitrogen and methane as a reaction gas into the chamber 1. By supplying an arc current of 100 A to the B layer cathode 7 while maintaining the voltage of the bias power supply 20 at −350 V at 2.0 Pa, metal ions are generated from the B layer cathode 7, and 0.5 μm An uppermost layer composed of Al _0.65 V _0.3 B _0.05 C _0.4 N _0.6 layer having a thickness was formed. Then, the current supplied to the bias power source 20 was stopped after the uppermost layer was formed.

  Except for the above, in the same manner as in Example 1, a coating layer composed of alternating layers of A layers and B layers and the uppermost layer was formed, and the surface-coated cutting tool (blade-replaceable cutting tip) of Example 14 was formed. Produced. When the cross section of the coating layer of the surface-coated cutting tool of Example 14 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 4.1 μm.

(Example 15)
With sets substrate 5 to a rotary substrate holder 4 of the cathode arc ion plating loading apparatus 30 shown in FIG. 3, to set the Al _0.7 Cr _0.3 target A layer for cathode 6, Al _0.7 to B layer for a cathode 7 A V _0.3 target was set.

Then, an A layer made of an Al _0.7 Cr _0.3 N _0.9 layer having a thickness of 0.006 μm is first formed on the substrate, and then a B layer made of an Al _0.7 V _0.3 N _0.9 layer having a thickness of 0.006 μm is formed. Thereafter, the A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.7 Cr _0.3 N _0.9 layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 15 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 15 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 3.6 μm.

(Example 16)
With sets substrate 5 to a rotary substrate holder 4 of the cathode arc ion plating loading apparatus 30 shown in FIG. 3, to set the Al _0.7 Cr _0.3 target A layer for cathode 6, Al _0.7 to B layer for a cathode 7 A V _0.3 target was set.

Then, an A layer made of an Al _0.7 Cr _0.3 N _1.1 layer having a thickness of 0.006 μm is first formed on the substrate, and then a B layer made of an Al _0.7 V _0.3 N _1.1 layer having a thickness of 0.006 μm is formed. Thereafter, the A layer and the B layer were alternately laminated one by one in this order (that is, the lowermost layer is an A layer composed of an Al _0.7 Cr _0.3 N _1.1 layer). In addition, about each thickness of A layer and B layer, it adjusted by increase / decrease in the rotational speed of the base material 5. FIG.

  When the number of layers A and B is 300 (total thickness of layer A: 1.8 μm, total thickness of layer B: 1.8 μm), cathodes 6 for A layer and B The current supplied to the layer cathode 7 was stopped.

  Except for the above, a coating layer composed of alternating layers of A and B layers was formed in the same manner as in Example 1, and a surface-coated cutting tool (blade-replaceable cutting tip) of Example 16 was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 16 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 3.6 μm.

(Comparative Examples 1-4)
For comparison, surface-coated cutting tools of Comparative Examples 1 to 4 in which a coating layer having the composition shown in Table 1 was formed on the same substrate as that of each of Examples 1 to 16 were produced. In the surface-coated cutting tools of Comparative Examples 1 to 3, the alternating layers are not formed as in the surface-coated cutting tools of Examples 1 to 16, but in Table 1, the surface coating of Comparative Examples 1 to 3 is used. The composition of the coating layer (single layer) of the cutting tool is described in the column of alternating layers A for convenience.

  Here, “one layer thickness” in Table 1 means the thickness of each of the A and B layers constituting the alternating layers. The values of the one layer thickness and the top layer thickness of the A layer and the B layer in Table 1 are values measured using SEM or TEM, respectively.

  Further, the “number of stacked layers” in Table 1 means the total number of layers of the A layer and the B layer in the alternating layers in which the A layer and the B layer are alternately stacked one by one.

  Further, the compositions of the A layer, the B layer, and the uppermost layer in Table 1 were measured using XPS (X-ray photoelectron spectroscopy analyzer).

In the composition of each of the A and B layers constituting the alternating layers in Table 1, for example, the B layer “Al _0.7 V _0.3 N” in Example 1 means a nitride containing Al and V, When the total number of metal atoms (ie, Al and V) constituting the B layer is 1, the ratio of the number of Al atoms is 0.7, and the ratio of the number of V atoms is 0.3 And the ratio of the number of N atoms when the total number of metal atoms is 1 is 1.

In the composition of the uppermost layer in Table 1, for example, the uppermost layer “Al _0.7 V _0.3 C _0.4 N _0.6 ” in Example 12 means a carbonitride containing Al and V, and the metal constituting the uppermost layer. When the total number of atoms (ie, Al and V) is 1, the ratio of the number of Al atoms is 0.7; the ratio of the number of V atoms is 0.3; When the total number is 1, the total number of atoms of C and N is 1, and when the total number of C and N is 1, the ratio of the number of C atoms is 0.4, and the ratio of the number of N atoms Is 0.6. In addition, the description regarding a composition shall show the same content also in another Example and a comparative example unless there is particular notice.

Here, the value of the hardness (GPa) of the coating layer in Table 2 is a value confirmed by a nanoindenter (Nano Indenter XP manufactured by MTS). Moreover, the compressive residual stress (-GPa) value of the coating layer in Table 2 was determined using the sin ² ψ method (“X-ray stress measurement method” (Japan Society of Materials Science, 1981 (Refer to pages 54 to 67) issued by Kendo). Further, the crystal structure of the entire coating layer in Table 2 was analyzed by an X-ray diffractometer. These notations and measurement methods are the same unless otherwise specified.

<Life evaluation of surface-coated cutting tools>
For each of the surface-coated cutting tools of Examples 1 to 16 and Comparative Examples 1 to 4 produced in the above steps, a dry face milling test (intermittent cutting test) and many holes were actually performed under the conditions shown in Table 3. A strong interrupted cutting test (strong interrupted cutting test) was performed with a punched block, and the time until the burr and the machined surface became cloudy and deviated from the product standard or the time until the cutting edge was broken (min) was measured. Table 4 shows the evaluation results of the tool life of these intermittent cutting tests and the strong intermittent cutting test. In Table 4, the larger the cutting time (min) value in the intermittent cutting test and the strong intermittent cutting test, the longer the tool life of the surface-coated cutting tool.

  As apparent from Table 4, like the surface-coated cutting tools of Examples 1 to 16, the coating layer includes alternating layers in which one or more of the A layers and the B layers are alternately laminated, and the A layer is made of Al. And the ratio of the number of Cr atoms when the total number of metal atoms constituting the A layer is 1, and the B layer is made of Al When the ratio of the number of V atoms is 0.05 or more and 0.4 or less when the total number of metal atoms constituting the B layer is 1 and is made of a nitride containing V, Comparative Examples 1 to 4 It was confirmed that the tool life of the surface-coated cutting tool (blade-replaceable cutting tip) in the intermittent cutting test and the strong intermittent cutting test was significantly longer than that of the surface-coated cutting tool.

  That is, the surface-coated cutting tools of Examples 1 to 16 of the present invention were excellent in stability at high temperatures, suppressed chipping of the blade edge, and succeeded in prolonging the tool life of the surface-coated cutting tool. Conceivable.

<Production of surface-coated cutting tool>
The surface-coated cutting tools of Examples 17 to 22 were produced as follows, and the tool life of each of the surface-coated cutting tools of Example 11, Examples 17 to 22, and Comparative Example 4 was evaluated.

(Example 17)
First, in the same manner as in Example 11, a layer A made of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm and a layer B made of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm were alternately formed 350 each. Alternating layers formed by layering were formed.

Next, while introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C. and the reaction gas pressure is set to 2.0 Pa. Metal ions are generated from the A layer cathode 6 by supplying a 100 A arc current to the A layer cathode 6 while maintaining a pulse DC of −100 V (pulse frequency 250 kHz, both ON time and OFF time 2 μsec). Then, on the B layer which is the uppermost layer of the alternating layers, the C layer made of the (Al _0.7 Cr _0.3 ) ₂ O ₃ layer having a thickness of 1.5 μm is formed so as to be the uppermost layer of the coating layer. A surface-coated cutting tool (blade tip exchangeable cutting tip) was produced.

  And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 17 was observed by SEM, it was confirmed that the thickness of the entire coating layer (total thickness) was 5.7 μm.

(Example 18)
While introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C., the reaction gas pressure is set to 2.0 Pa, and the voltage of the bias power source 20 is set to −100V. By supplying a 100 A arc current to the B layer cathode 7 while maintaining the pulse DC (pulse frequency 250 kHz, ON time and OFF time 2 μsec), metal ions are generated from the B layer cathode 7 alternately. Example 18 was carried out in the same manner as Example 17 except that a C layer composed of an (Al _0.7 V _0.3 ) ₂ O ₃ layer having a thickness of 1 μm was formed as the uppermost layer of the coating layer on the uppermost B layer. A surface-coated cutting tool (blade tip exchangeable cutting tip) was produced. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 18 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 5.2 μm.

(Example 19)
While introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C., the reaction gas pressure is set to 2.0 Pa, and the voltage of the bias power source 20 is set to −100V. By supplying a 100 A arc current to the A layer cathode 6 or the B layer cathode 7 while maintaining the pulse DC (pulse frequency 250 kHz, ON time and OFF time 2 μsec), the A layer cathode 6 and the B layer The metal ions are alternately generated from the cathode 7 and the (Al _0.7 Cr _0.3 ) ₂ O ₃ layer and the (Al _0.7 V _0.3 ) ₂ O ₃ layer are alternately formed on the uppermost B layer of the alternating layer. The surface-coated cutting tool of Example 19 (blade-replaceable cutting chip) was obtained in the same manner as in Example 17 except that a C layer composed of a 1 μm thick super-multilayer film formed in multiple layers was formed as the uppermost layer of the coating layer. Was made. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 19 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 5.2 μm.

(Example 20)
First, in the same manner as in Example 17, a layer A made of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm and a layer B made of an Al _0.7 V _0.3 N layer having a thickness of 0.006 μm were alternately formed 350 each. Alternating layers formed by layering were formed.

Next, an Al _0.7 Cr _0.29 Y _0.01 target was set on the cathode 6 for the A layer, and an Al _0.7 V _0.29 Y _0.01 target was set on the cathode 7 for the B layer.

Thereafter, while introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C., the reaction gas pressure is set to 2.0 Pa, and the voltage of the bias power supply 20 is − By supplying a 100 A arc current to the A layer cathode 6 or the B layer cathode 7 while maintaining a 100 V pulse DC (pulse frequency 250 kHz, both ON time and OFF time 2 μsec), the A layer cathode 6 Metal ions are alternately generated from the cathode 7 for the B layer, and the (Al _0.7 Cr _0.29 Y _0.01 ) ₂ O ₃ layer and the (Al _0.7 V _0.29 Y _0.01 ) ₂ O _{3 are formed} on the uppermost B layer of the alternating layer. A surface-coated cutting tool (blade-replaceable cutting tip) of Example 20 was formed by forming a C layer made of a 2.5 μm-thick super multi-layer film alternately formed in multiple layers, as the uppermost layer of the coating layer. It was manufactured. And after formation of a coating layer, the gas in the cathode arc ion plating apparatus 30 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 20 was observed by SEM, it was confirmed that the thickness of the entire coating layer (total thickness) was 6.7 μm.

(Example 21)
Using the cathode arc ion plating-sputtering composite apparatus 40 shown in FIG. 7, in the same manner as in Example 17, an A layer composed of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm and an Al _0.7 V _0.3 having a thickness of 0.006 μm. Alternate layers were formed by alternately laminating 350 layers of N layers and B layers one by one.

Next, an Al _0.7 Cr _0.29 Y _0.01 target was set on the sputter cathode 16. Thereafter, while introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C., the reaction gas pressure is set to 2.0 Pa, and the voltage of the bias power supply 20 is − Sputtering was performed via a sputter cathode pulse DC power source (pulse frequency 100 kHz, ON time was 8 μsec, and OFF time was 2 μsec) while maintaining a 100 V pulse DC (pulse frequency 250 kHz, ON time and OFF time 2 μsec). A metal ion is generated from the sputter cathode 16 by supplying a power of 3 kW to the cathode 16, and a C having 3 μm thick (Al _0.69 Cr _0.29 Y _0.02 ) ₂ O ₃ layer on the uppermost B layer of the alternating layer. The surface is formed as the uppermost layer of the coating layer, and the surface-coated cutting tool (blade-replaceable cutting tip) of Example 21 is produced. It was.

  After the coating layer was formed, the gas in the cathode arc ion plating / sputtering composite apparatus 40 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 21 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 7.2 μm.

(Example 22)
Using the cathode arc ion plating-sputtering composite apparatus 40 shown in FIG. 7, in the same manner as in Example 17, an A layer composed of an Al _0.7 Cr _0.3 N layer having a thickness of 0.006 μm and an Al _0.7 V _0.3 having a thickness of 0.006 μm. Alternate layers were formed by alternately laminating 350 layers of N layers and B layers one by one.

Next, an Al _0.69 Cr _0.2 V _0.09 Y _0.02 target was set on the sputter cathode 16. Thereafter, while introducing oxygen and argon gas as reaction gases into the chamber 1, the temperature of the substrate 5 is set to 700 ° C., the reaction gas pressure is set to 2.0 Pa, and the voltage of the bias power supply 20 is − Sputtering was performed via a sputter cathode pulse DC power source (pulse frequency 100 kHz, ON time was 8 μsec, and OFF time was 2 μsec) while maintaining a 100 V pulse DC (pulse frequency 250 kHz, ON time and OFF time 2 μsec). Metal ions are generated from the sputter cathode 16 by supplying a power of 3 kW to the cathode 16, and the (Al _0.69 Cr _0.2 V _0.09 Y _0.02 ) ₂ O ₃ layer having a thickness of 3 μm is formed on the uppermost B layer of the alternating layer. And forming the C layer as the uppermost layer of the coating layer, the surface-coated cutting tool of Example 22 (blade replaceable cutting tip) It was manufactured.

  After the coating layer was formed, the gas in the cathode arc ion plating / sputtering composite apparatus 40 was exhausted. When the cross section of the coating layer of the surface-coated cutting tool of Example 22 was observed by SEM, it was confirmed that the total thickness (total thickness) of the coating layer was 6.7 μm.

  Table 5 shows the configuration of the coating layer of each surface-coated cutting tool of Example 11 and Examples 17 to 22 and Comparative Example 4, and Table 6 shows the characteristics (hardness and compressive residual stress) of the coating layer of the surface-coated cutting tool. And the crystal structure of the C layer, which is the uppermost layer of the coating layer.

  Note that the crystal structure of the C layer, which is the uppermost layer of the coating layer in Table 6, was analyzed by an X-ray diffractometer. In addition, notations shown in Table 5 and Table 6 other than the above are the same as those described above, and thus the description thereof is omitted here.

<Life evaluation of surface-coated cutting tools>
Each of the surface-coated cutting tools of Example 11 and Examples 17 to 22 and Comparative Example 4 was actually subjected to a dry face milling test (intermittent cutting test) under the conditions shown in Table 7, and a strong interrupt by a block having many holes. A machining cutting test (strong interrupted cutting test) and a continuous turning test were performed, and the time until the burrs and the machined surface became cloudy and deviated from the product specification, or the time until the cutting edge was broken (min) was measured. Table 7 shows the cutting conditions (work material, cutting speed) of the surface-coated cutting tools of Example 11 and Examples 17 to 22 and Comparative Example 4 when the intermittent cutting test, the strong intermittent cutting test, and the continuous turning test were performed. vc, feed fz and notch ap). Table 8 shows the evaluation results of the tool life when the intermittent cutting test, the strong intermittent cutting test, and the continuous turning test were performed on the surface-coated cutting tools of Example 11, Examples 17 to 22, and Comparative Example 4. . In Table 8, the larger the cutting time (min) value in the intermittent cutting test, the strong intermittent cutting test, and the continuous turning test, the longer the tool life of the surface-coated cutting tool.

  As apparent from Table 8, like the surface-coated cutting tools of Example 11 and Examples 17 to 22, the coating layer includes alternating layers in which one or more of the A layers and the B layers are alternately laminated, The A layer is made of a nitride containing Al and Cr, and the ratio of the number of Cr atoms when the total number of metal atoms constituting the A layer is 1 is greater than 0.05 and less than or equal to 0.4. When the layer is made of a nitride containing Al and V, and the ratio of the number of V atoms satisfies 0.05 to 0.4 when the total number of metal atoms constituting the B layer is 1, a comparison is made. Compared with the surface-coated cutting tool of Example 4, it was confirmed that the tool life of the surface-coated cutting tool (blade-tip-exchangeable cutting tip) in the intermittent cutting test, the strong intermittent cutting test, and the continuous turning test was significantly increased.

  That is, the surface-coated cutting tools of Example 11 and Examples 17 to 22 of the present invention are excellent in stability at high temperatures, suppress chipping of the blade edge, and prolong the tool life of the surface-coated cutting tool. It is considered successful.

  Although the embodiments and examples of the present invention have been described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The surface-coated cutting tool of the present invention can be suitably used, for example, as a drill, end mill, milling throw-away tip, turning throw-away tip, metal saw, gear cutting tool, reamer, or tap.

  1 chamber, 2 gas inlet, 3 gas outlet, 4 rotary base holder, 5 base, 6 A layer cathode, 7 B layer cathode, 8, 9 arc power supply, 10 surface coating cutting tool, 11 coating Layer, 12 A layer, 13 B layer, 14 alternating layer, 15 C layer, 16 sputter cathode, 20 bias power source, 40 cathode arc ion plating-sputtering composite apparatus.

Claims (11)

A substrate;
A surface-coated cutting tool comprising a coating layer formed on the surface of the substrate,
The coating layer includes alternating layers in which one or more A layers and B layers are alternately laminated,
The A layer is seen containing Al and Cr, a nitride not containing V,
The atomic ratio of Cr when the total number of metal atoms constituting the A layer is 1 is greater than 0.05 and 0.4 or less,
The B layer is seen containing Al and V, a nitride which does not contain Cr,
The surface-coated cutting tool, wherein the atomic ratio of V is 0.05 or more and 0.4 or less when the total number of metal atoms constituting the B layer is 1.   The surface-coated cutting tool according to claim 1, wherein the thickness of the A layer and the thickness of the B layer are each greater than 1 nm and 200 nm or less.   3. The surface according to claim 1, wherein an atomic ratio of the Cr of the A layer adjacent in the coating layer and an atomic ratio of the V of the B layer are substantially the same. Coated cutting tool.   The surface-coated cutting tool according to claim 1, wherein a lowermost layer of the coating layer is the A layer.   The surface-coated cutting tool according to claim 1, wherein the lowermost layer of the coating layer is the B layer. In the alternating layers, the A layer and the B layer are stacked with an intermediate transition layer interposed therebetween,
The composition of the intermediate transition layer continuously changes in the thickness direction from the composition of the lower layer in contact with the intermediate transition layer to the composition of the upper layer in contact with the intermediate transition layer. The surface-coated cutting tool according to 1.   The surface-coated cutting tool according to any one of claims 1 to 6, wherein the coating layer has an average residual stress of -8 GPa or more and 0 GPa or less.   The residual stress of the coating layer changes in the thickness direction of the coating layer, and the absolute value of the residual stress of the coating layer increases as the distance from the base material increases. The surface-coated cutting tool according to 1.   The surface-coated cutting tool according to claim 1, wherein the crystal structure of the coating layer is a cubic crystal.   The uppermost layer of the coating layer includes a C layer made of an oxide containing Al as a main component and containing at least one of Cr and V and Al, and the total number of metal atoms constituting the C layer is 1. The surface-coated cutting tool according to any one of claims 1 to 9, wherein a ratio of the total number of atoms of Cr and V is greater than 0 and 0.4 or less.   The C layer further includes Y, and the ratio of the number of Y atoms when the total number of metal atoms constituting the C layer is 1 is greater than 0.01 and 0.1 or less. The surface-coated cutting tool according to claim 10.

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