JP4707541B2 - Hard coating coated member - Google Patents

Description

The present invention relates to a hard film-coated member whose surface is coated with a hard film . Examples of the member include wear-resistant tools that require high hardness such as cutting tools, dies, bearings, dies, and rolls.

  As for the hard film covering member, configurations of a lowermost layer and an intermediate laminated portion are disclosed in Patent Documents 1 to 3 below.

JP 2003-71610 A Japanese Patent Laid-Open No. 2004-238736 JP-A-7-205361

The present invention has a hard film coating which has a hard film intermediate layered portion containing Al, Cr and Ti as essential components, thereby increasing the hardness and improving the wear resistance with excellent heat resistance and lubrication characteristics. It is an object to provide a member.

The hard film covering member of the present invention is a hard film covering member obtained by coating the base layer surface with the lowermost layer, the intermediate laminated portion and the uppermost layer, and the intermediate laminated portion has a metal component composition (Al _W Cr _X Ti _Y Si _Z ) (however, in atomic%, W + X + Y + Z = 100) A layer and B layer made of any of nitrides, borides, carbides and oxides, or a solid solution or a mixture thereof. The layers A and B are alternately diffused layers of Al, Cr, and Ti, and the composition of the layer A is 70 <W + X <100, 45 ≦ W ≦ 65, 25 ≦ X ≦ 35, 0 <Y ≦ 10, and 0 <Z ≦ 10, and the composition of layer B is atomic percent 0 <W ≦ 10, 0 <X ≦ 10, 86.09 <Y <100 and 0 <Z. <30,
The uppermost layer is characterized by being Ti or Ti and Si nitride or carbonitride.
By adopting the above configuration, it is possible to achieve high hardness by having an intermediate laminated part of a hard film containing Al, Cr and Ti as essential components while having excellent heat resistance and lubrication characteristics. . At the same time, since the hard coatings to be laminated are formed in a state having excellent adhesion strength, peeling between the two layers hardly occurs and the peeling resistance and chipping resistance are excellent.

By applying the present invention , it is possible to increase the hardness of the intermediate laminated portion of the hard film containing Al , Cr and Ti as essential components while having excellent heat resistance and lubrication characteristics. In addition, it has been possible to provide an optimum hard film for a member that requires wear resistance in a severe wear environment, and to provide a member coated with this hard film. For example, it has been possible to provide a hard film coating tool and a hard film coating method that exhibit excellent wear resistance in high speed cutting and deep hole machining. This is because the laminated hard coatings each have excellent adhesion strength, delamination hardly occurs, and has high hardness, and is excellent in peeling resistance and chipping resistance, so that abnormal wear hardly occurs. It is because the effect was demonstrated.

In the present invention, the layer structure of the hard coating is important. It shows a schematic view of a laminated structure of hard film definitive to the present invention in FIG. The layer structure of the hard coating consists of multiple layers of hard coatings with different compositions formed by physical vapor deposition on the substrate, and consists of the lowermost layer, the uppermost layer, and the intermediate laminated portion in contact with the lowermost layer and the uppermost layer. . When there is no uppermost layer that exhibits excellent functions such as high hardness, heat resistance, and lubricity, the wear resistance effect cannot be exhibited. When the lowermost layer does not exist, it is not possible to absorb the residual stress of the upper intermediate layer and the uppermost layer, resulting in a wear state preceded by peeling and abnormal wear, and stable wear resistance cannot be improved. When there is no intermediate laminated portion, the characteristics of the uppermost layer cannot be fully exhibited.
Intermediate laminate portion, a nitride of composition of the metal component _{(Al W Cr X Ti Y Si} Z), borides, made from either or their solid solution or a mixture of carbides and oxides, the composition of the metal component at% W + X + Y + Z = 100, and in the laminated portion, the A layer and the B layer are alternately laminated in the layer thickness direction, the composition of the A layer is 70 <W + X <100, and the composition of the B layer is 30 <Y. By being <100, the balance of hardness, adhesion, and lubricity between the lowermost layer and the uppermost layer is optimal, and the hardness and heat resistance of the entire hard coating can be improved. The A layer is an atomic% of only the metal component, and when W + X + Y + Z = 100, it is important to satisfy 70 <W + X <100. When the value of W + X is 70 or less, the heat resistance improvement effect is not sufficient, and the increase in hardness due to the combination with the B layer is not confirmed. By containing W and Z even in a small amount, the hardness of the A layer and the B layer is improved. It is important for the B layer to satisfy 30 <Y <100 when W + X + Y + Z = 100 with atomic% of only the metal component. When the value of Y is 30 or less, it is confirmed that the adhesion strength between the A layer and the B layer is lowered and the hardness of the intermediate laminated portion is lowered. This is because the hcp structure appears in the product structure of the intermediate laminated portion.

The composition of the metal component of the A layer of the intermediate laminated portion according to the present invention is atomic%, 45 ≦ W ≦ 65, 25 ≦ X ≦ 35, 0 <Y ≦ 10, and 0 <Z ≦ 10. The composition is 0 <W ≦ 10, 0 <X ≦ 10, 86.09 <Y <100 and 0 <Z <30 in atomic percent. The stacking period in the layer thickness direction between the A layer and the B layer in the intermediate stacked portion is 0.5 nm or more and less than 100 nm, and has at least two peaks in the range of 40 to 45 degrees at 2θ in X-ray diffraction. It is preferable. It is necessary that the A layer and the B layer constituting the intermediate laminated portion are at least Al, Cr, and Ti interdiffusion layers, and the A layer and the B layer preferably have a continuous crystal lattice. Furthermore, it is preferable that the Si content of the intermediate laminated portion is different in the layer thickness direction, and that the Si content increases as it becomes closer to the surface layer side.
The lowermost layer is preferably a hard nitride film made of one or more metal elements selected from Al, Cr, Ti and Si. It is preferable that Al is contained by 50 atomic% or more, and the balance is one or more nitrides selected from Ti, Cr and Si.
The uppermost layer is preferably mainly composed of carbonitride or nitride containing 50 atomic% or more of Ti.
The layer thickness T μm of the uppermost layer is 0.01 ≦ T <5, the layer thickness M μm of the intermediate laminated portion is 0.1 ≦ M <5, and the layer thickness B μm of the lowermost layer is 0.01 ≦ B <3 and preferably M ≦ T ≦ B. The hardness H of the intermediate laminated portion is in the range of 30 GPa ≦ H ≦ 50 GPa, the elastic modulus E is in the range of 450 GPa ≦ E ≦ 550 GPa, and the elastic recovery rate R is in the range of 28% ≦ R ≦ 38%. It is preferable. The uppermost layer preferably contains oxygen and preferably has a maximum value of oxygen concentration in a depth region within 100 nm from the outermost surface in the film thickness direction. Moreover, it is preferable that a member is an end mill or a drill, and a base | substrate is a high speed steel, a cemented carbide, or a cermet.

  The coating method employs a physical vapor deposition method, and the physical vapor deposition method is preferably a sputtering method and / or an arc discharge ion plating (hereinafter referred to as AIP) method. A more preferable coating method is that the composition of the metal target material used for coating the hard coating differs between the top layer coating and the bottom layer coating, and when the intermediate laminated portion is coated, the composition for the top layer coating is different. It is preferable to use a method in which a vapor deposition source equipped with a target material and a vapor deposition source equipped with a target material for coating the lowermost layer are simultaneously operated and coated.

The lowermost layer preferably contains a hard film mainly composed of one or more nitrides containing 50 atomic% or more of Al and the balance selected from Ti, Cr and Si. As a result, it acts effectively as an intermediate laminated portion and an uppermost stress relaxation layer. Here, it is preferable that the interface between the lowermost layer and the intermediate laminated portion is an interdiffusion layer of both, and this provides excellent adhesion strength. The term “nitride-based” means that a small amount of oxygen, carbon, boron or sulfur may be contained as a nonmetallic component other than nitrogen.
The uppermost layer is a hard coating of Ti or a nitride and carbonitride of Ti and Si. Lubricity and film hardness can be further improved by the uppermost layer. Here, it is preferable that the interface between the uppermost layer and the intermediate laminated portion be an interdiffusion layer of the both, and this provides excellent adhesion strength. When the uppermost layer is coated on the upper layer side of the intermediate laminated portion, peeling and abnormal wear are remarkably suppressed, and the lubricity of the entire hard coating is improved.
The combination of the lowermost layer, the intermediate layer, and the uppermost layer is extremely important.
By controlling to the composition range of the present invention , the intermediate laminated portion is increased in hardness with excellent lubricity and heat resistance, excellent adhesion strength between the A layer and the B layer, and the lowermost layer and the uppermost layer. The adhesive strength is also excellent, and the balance of the strength of the entire hard coating is optimal and preferable.
The lowermost layer preferably contains 50 atomic% or more of Al, and the balance is one or more nitrides selected from Ti, Cr and Si. Thereby, it is excellent in adhesive strength with an intermediate lamination part, and can relieve the residual stress of an intermediate lamination part simultaneously. In particular, the effect is remarkably exhibited in the case of an iron-based substrate.

The uppermost layer is preferably mainly composed of carbonitride or nitride containing 50 atomic% or more of Ti with only atomic% of the metal element. The main component of carbonitride or nitride here is achieved even if it contains several percent of elements inevitably mixed. The uppermost layer has excellent adhesion strength with the intermediate laminated portion, and at the same time, the chip discharging property is remarkably improved by the effect of the lubricating property. It is particularly suitable as a coating layer for drills.
The layer period in the layer thickness direction of the A layer and the B layer is 0.5 nm or more and less than 100 nm, and it is a hard film having at least two peaks in the range of 40 to 45 degrees at 2θ in X-ray diffraction. It is preferable. By alternately laminating the thicknesses of the A layer and the B layer at a cycle of 0.5 nm or more and less than 100 nm in the layer thickness direction, the intermediate laminated portion containing Al, Cr, and Ti as essential components is increased in hardness, The balance between the adhesion strength between the lowermost layer and the uppermost layer and the strength of the entire hard coating is optimal. Moreover, the lubricity and hardness of the uppermost layer are improved by coating the uppermost layer on the upper layer side of the intermediate laminated portion. When the thicknesses of the A layer and the B layer are less than 0.5 nm in the layer thickness direction, the film hardness and the lubricity are lowered. On the other hand, when the thickness is 100 nm or more, it is not possible to sufficiently increase the hardness of the intermediate laminated portion containing Al, Cr, and Ti as essential components. It is preferable that the A layer and the B layer are alternately stacked so that the thicknesses are 0.5 nm or more and less than 100 nm. Therefore, in addition to the above structure, even when there is a laminated layer whose composition varies with a layer thickness of 100 nm or more, if there is a laminated part composed of the A layer and the B layer of 0.5 nm or more and less than 100 nm, The effect is demonstrated. It is preferable to have at least two peaks in the range of 40 ° to 45 ° at 2θ in the X-ray diffraction of the intermediate laminated portion. This indicates that a phase having two or more different lattice constants is formed in the intermediate laminated portion, which induces strain in the intermediate laminated portion and effectively acts for increasing the hardness.
It is necessary that the A layer and the B layer constituting the intermediate laminated portion are at least Al, Cr and Ti interdiffusion layers. In this case, the adhesion strength between the A layer and the B layer and the adhesion strength between the lowermost layer and the uppermost layer are excellent, and the hardness of the intermediate laminated portion is improved. Furthermore, the balance of the strength of the entire hard coating becomes optimal, and this is a particularly preferable layer structure.

The presence or absence of a mutual diffusion layer is confirmed by observation of a lattice image with a transmission electron microscope and energy dispersive X-ray spectroscopy (hereinafter referred to as EDS) analysis of each layer when the composition of the metal target material constituting each layer is known. can do. In this case, it can judge from the composition of the metal target material which comprises each layer, and the composition of A layer and B layer. Moreover, when mutual diffusion does not occur in the A layer and the B layer, it is a case where a solid solution is not formed by the A layer and the B layer, and a layer composed only of the target component is formed.
The A layer and the B layer in the intermediate laminated part preferably have a continuous crystal lattice. In this case, adhesion strength and wear resistance between the A layer and the B layer can be exhibited. The confirmation method of this structure is confirming from the lattice image observation by a transmission electron microscope, and the limited field diffraction image or the minute part electron beam diffraction of the A layer and the B layer. It is preferable that the Si content in the intermediate laminated portion is different in the layer thickness direction, and that the Si content is higher in the surface layer. As a result, the adhesion strength, hardness, and strength are graded at the intermediate laminated portion, and as a result, the adhesion strength, heat resistance, hardness, and membrane strength of the entire hard coating are graded, and wear resistance can be improved. .
It is preferable that Mμm of the intermediate laminated portion satisfies 0.1 ≦ M <5. When the intermediate laminate portion is less than 0.1 μm, the balance between the adhesion strength, hardness, and strength of the uppermost layer and the lowermost layer is poor, and the effect of improving the wear resistance may not be exhibited.
It is preferable that Tμm of the uppermost layer is 0.01 ≦ T <5. When the uppermost layer is less than 0.01 μm, the effect of the lowermost layer is not confirmed, and the wear resistance is not stable. When the lowermost layer is 5 μm or more, the wear resistance effect is not confirmed, which is not preferable.
It is preferable that B μm of the lowermost layer is 0.01 ≦ B <3. When the lowermost layer is less than 0.01 μm, the effect of improving the wear resistance by increasing the hardness of the uppermost layer is not confirmed. When the thickness of the uppermost layer is 3 μm or more, peeling of the hard film or abnormal wear may occur, which is not preferable. Furthermore, when the relationship of M ≧ T ≧ B is satisfied, the effect is exhibited to the maximum and a particularly preferable layer structure is obtained.

It is preferable that the hardness H of the intermediate laminated portion is in a range of 30 GPa ≦ H ≦ 50 GPa. By adopting the intermediate laminated part in the above range, the balance of adhesion strength, lubricity and heat resistance of the entire hard film is optimal, and the effects of the lowermost layer and the uppermost layer are maximized, and wear resistance It is effective for improving sex.
The elastic modulus E of the intermediate laminated part is preferably in the range of 450 GPa ≦ E ≦ 550 GPa. When the E value is within this range, the balance of adhesion strength, lubricity, and heat resistance of the entire hard coating is optimal, and the effects of the lowermost layer and the uppermost layer are maximized to improve adhesion strength. It is effective. The elastic recovery rate R of the intermediate laminated portion is preferably in the range of 28% ≦ R ≦ 38%. When the R value is less than 28%, the wear resistance is poor, and when it exceeds 38%, the peel resistance is poor and abnormal wear tends to occur. When the R value is within this range, the balance of adhesion strength, lubricity and heat resistance of the entire hard coating is optimal, and the effects of the lowermost layer and the uppermost layer are maximized and effective against abnormal wear. Is. As a method for measuring the hardness H, the elastic modulus E, and the elastic recovery rate R, the contact depth and the maximum displacement at the maximum load are obtained by a hardness measurement method by nanoindentation (WC Oliver and GM Pharr). : J. Mater.Res., Vol.7, No.6, June, 1992, 1564-1583). The elastic recovery rate R is defined by the equation R = 100 − {(contact depth) / (maximum displacement at maximum load)}. The hardness here is different from the plastic deformation hardness represented by the usual measuring method such as Vickers hardness.
The uppermost layer preferably contains oxygen, and the oxygen concentration is preferably maximized in a depth region within 100 nm in the film thickness direction. This is particularly effective for suppressing adhesion of the workpiece to the hard coating surface.

When the target member is an end mill or a drill, and this is coated with a hard film, the effect of improving wear resistance is remarkable, and tool wear can be remarkably reduced, which is preferable. Those having improved lubricity are particularly suitable for drills.
As for the coating method, the hard film-coated member coated by the sputtering method and / or the AIP method has a particularly high hardness and excellent adhesion strength, excellent peeling and abnormal wear suppression, and its effects are easily obtained. The hard coating is coated by sputtering and / or AIP. In the coating method, the composition of the metal target material used when coating the hard coating is different between the uppermost layer coating and the lowermost layer coating. During the coating, the vapor deposition source equipped with the target material for the uppermost layer coating and the vapor deposition source equipped with the target material for the lowermost layer coating are simultaneously operated and coated. By adopting this coating method, it is possible to obtain a hard film-coated member capable of exhibiting excellent wear resistance. As an example of the above-described coating method, the lowermost layer coating is first coated with the metal target 1 made of the lowermost layer constituent element, and then the discharge with the metal target 2 made of the uppermost layer constituent element is started. 1 and the metal target 2 simultaneously cover the intermediate laminated portion. Next, the coating with the metal target 1 is stopped, and the uppermost layer is coated with the metal target 2. Hereinafter, a description will be given based on examples.

Example 1
An AIP apparatus was used for the coating of the example of the present invention. FIG. 2 shows a schematic diagram of the apparatus, and the configuration and covering method will be described. The apparatus configuration includes a plurality of arc discharge evaporation sources 4, 5, 6, 7 and a substrate holder 8 that are insulated from the decompression vessel 3. Evaporation sources 4 to 7 are equipped with targets 1 and 2, which are metal components of the hard coating, and a predetermined current is supplied to each evaporation source to cause arc discharge on targets 1 and 2, thereby evaporating and ionizing the metal target components. Then, the substrate 9 was coated with a negative bias voltage applied between the decompression vessel 3 and the substrate holder 8. The substrate 9 has a rotation mechanism 10 and was rotated in the range of 1 to 10 rotations / minute. That is, when the substrate 9 is opposed to the front surface of the target 1, the hard coating containing the target 1 is coated, and when the substrate 9 is opposed to the front surface of the target 2, the hard coating containing the target 2 is coated. At this time, when the nitride containing each target material component was formed, the film was formed while introducing nitrogen gas. In the evaluation of the present invention example, an insert of JIS standard SNGA432 was manufactured using a cemented carbide having a composition of mass%, a Co content of 13.5%, the remaining WC and inevitable impurities. The substrate was degreased and cleaned and loaded into the substrate holder 8. The substrate was heated to 550 ° C. by a heating heater installed in the decompression vessel 3, and this state was maintained for 30 minutes for heating and degassing. Subsequently, Ar gas was introduced into the decompression vessel 3, and Ar was ionized by a hot filament installed in the decompression vessel 3. The substrate was cleaned with Ar ions for 30 minutes by a bias voltage applied to the substrate. Here, the method of adding carbon, oxygen, nitrogen, and boron components to the hard coating is based on the reaction gas N ₂ gas, CH ₄ gas, C ₂ H ₂ gas, Ar gas, O ₂ gas, CO gas, etc. It is possible to select a gas species so that a coating composition of 1 is obtained and introduce it into the vacuum vessel 3 during the coating process, or to add it to a metal target in advance.

The target material used for the hard film of Example 1 of the present invention is a metal target prepared by a powder method. In Example 1 of the present invention, Al ₆₀ Cr ₃₇ Si ₃ having a composition of atomic% was attached to the arc discharge evaporation sources 4 and 6 as the target material 1 for lowermost layer coating. Ti100 was attached to the arc discharge evaporation sources 5 and 7 as the target material 2 for covering the uppermost layer.
First, power of 25 V and 100 A is supplied to the evaporation source on which the target material 1 is mounted, the negative bias voltage is 50 V, the reaction gas pressure is 4 Pa, the coated substrate temperature is 500 ° C., and the substrate holder 8 is rotated 3 times / minute. And a nitride film of about 200 nm was coated on the surface of the substrate. The jig holding the coated substrate was rotated at 3 revolutions / minute. The composition of the target material 1 at this time was Al ₆₀ Cr ₃₇ Si ₃ , whereas the composition of the metal component in the hard film composition was Al ₅₇ Cr ₄₁ Si ₂ nitride. This hard film is the lowermost layer of Example 1 of the present invention.
Secondly, in the intermediate laminated portion, power of 25 V and 100 A was supplied to the evaporation source on which the target material 1 was mounted, and power of 20 V and 60 A was supplied to the evaporation source on which the target material 2 was mounted. In this state, all the vapor deposition sources equipped with the target materials 1 and 2 were simultaneously operated to start the coating of the nitride film. And the film-forming conditions of the nitride film were changed continuously. That is, the current supplied to the evaporation source equipped with the target material 2 is gradually increased from 60 A to 100 A as the coating time elapses, and at the same time, the current of the evaporation source equipped with the target material 1 is increased along with the elapse of the coating time. The coating was carried out by changing from 100 A to 60 A stepwise. A pulse bias voltage was applied to the substrate during coating. The conditions were a negative bias voltage of 60 V, a positive bias voltage of 10 V, a frequency of 20 kHz, an amplitude of 80% on the negative side, and 20% on the positive side. The total pressure is 6 Pa, the substrate temperature is 525 ° C., the jig for holding the coated substrate is rotated at 6 revolutions / minute, and the intermediate laminates of the respective nitrides released from the two types of targets 1 and 2 are target materials. Was coated at about 2600 nm.
Third, for the uppermost layer, the power supply to the evaporation source on which the target material 1 was mounted was stopped, and the film formation conditions were changed stepwise. Negative bias voltage is 100 V, positive bias voltage is 0 V, frequency is 10 kHz, amplitude is 95% on the negative side, 5% on the positive side, and total pressure is 1.5 Pa (N ₂ : 100 sccm, Ar: 30 sccm, C ₂ H ₂ 20 sccm), the substrate temperature was set to 500 ° C., and the substrate rotation speed was set to 3 revolutions / minute, and the carbonitride by the target material 2 was coated with about 200 nm.
The sample obtained by the first to third steps was taken as Example 1 of the present invention.
The layer thickness, film structure, composition and crystal structure of the intermediate laminated part of the hard film according to Example 1 of the present invention were confirmed. Qualitative analysis of crystal structure by X-ray diffraction and analysis of nano-region by transmission electron microscope were performed. A method for qualitative analysis of the crystal structure by X-ray diffraction will be described. The equipment used was Rotaflex Rotaflex, RV-200B, X-ray diffractometer. The conditions were set such that the tube voltage was 120 kV, the current was 40 μA, the X-ray source was Cukα, the incident angle was 5 degrees, the incident slit was 0.4 mm, and 2θ was 30 degrees to 70 degrees. Qualitative analysis of the crystal structure of the obtained hard coating was performed. In X-ray diffraction, in order to clarify the peak separation from the lowermost layer, the laminated portion, and the uppermost layer of Invention Example 1, a hard film composed only of the intermediate laminated portion of Invention Example 1 is formed. Evaluation was performed. An X-ray diffraction chart is shown in FIG. From FIG. 3, the intermediate laminated portion of Example 1 of the present invention showed an fcc structure. It was confirmed that the hard film had at least two peaks in the range of 40 to 45 degrees at 2θ. 3 is a diffraction peak from the fcc structure (111) plane of the B layer, peak 2 is a diffraction peak from the (111) plane of the A layer, and peak 3 is a diffraction from the (200) plane of the B layer. Peaks and peaks 4 are diffraction peaks from the (200) plane of the A layer. Next, a nano region analysis method using a transmission electron microscope (hereinafter referred to as TEM) will be described. As preparation of the sample used for the structure observation by TEM, the sample and the dummy substrate were bonded using an epoxy resin, and cut, reinforcing ring bonding, polishing, dimple ring, and Ar ion milling were performed. In the region where the sample thickness becomes the atomic layer thickness, the structure observation, lattice image observation, micro part (φ1 nm) energy dispersive X-ray spectroscopy (hereinafter referred to as EDS) analysis, micro part (φ1 nm) electron diffraction Done and determined the organizational structure. As for the observation position of TEM, the vicinity of the center was observed in the layer thickness direction of the intermediate laminated portion. As the apparatus used, a JEM-2010F type electrolytic emission transmission electron microscope (hereinafter referred to as FE-TEM) manufactured by JEOL Ltd. was used. The condition was that the structure was observed at an acceleration voltage of 200 kV, and the composition of the laminated film of nanometer order was determined for the micro EDS analysis using a Nolan UTW Si (Li) semiconductor detector attached to the apparatus. At this time, using an electron probe having a half-value width of 1 nm, it is considered that the beam is actually expanded when passing through the sample, and the region where X-rays are generated is expanded. However, the information obtained as a result is considered to be less than 2 nm. If the layer thickness is 2 nm or more, composition quantitative analysis by EDS analysis is possible. In addition, all the information in the depth direction is considered to be included, but since the sample thickness is the atomic layer thickness, it is considered to be information on the particles themselves. In general, when the sample is thinned, the number of X-rays obtained is reduced, so that the quantitative accuracy is considered to deteriorate. However, from this measurement result, the variation range was less than about 2%. Micro-electron beam diffraction focused the camera length to 50 cm and the beam diameter to 1 nm, and identified the crystal structure of the nanometer-order laminated film. FIG. 4 shows an observation image of the hard film structure by scanning transmission electron microscopy (hereinafter referred to as STEM) of an arbitrarily selected film cross section of the laminated portion of Example 1 of the present invention. From FIG. 4, it was confirmed that the intermediate laminated portion of Invention Example 1 had a nano-order constant periodic structure, and the thickness of each layer was about 0.5 nm or more and less than 100 nm. A preferable layer thickness at which the effects of the present invention can be easily obtained is 1 nm or more and less than 70 nm, and more preferably 2 nm or more and less than 50 nm. FIG. 5 shows a limited field diffraction image of the intermediate laminated portion 1250 nmφ in FIG. From FIG. 5, the ring resulting from two types of lattice constant was recognized by the intermediate | middle laminated part of this invention example 1 like the X-ray-diffraction result. In addition, since the inner and outer intensity distributions are the same in each ring, the orientation is uniform in each crystal grain, and the lattice is continuously grown in the film thickness direction. FIG. 6 shows an enlargement of FIG. Table 1 shows the results of EDS composition analysis at positions corresponding to numbers 1 to 5 in FIG.

In FIG. 6, number 1 and number 3 are the same layer, and number 2, number 4 and number 5 are the same layer. From Table 1, the Al content of the A layer of Invention Example 1 is atomic% of only the metal element, Al is 61.22% to 62.65%, and the Al content of the B layer is from 0.93%. It was 6.21%. What should be noted here is that the base is placed on a base holder having a rotation mechanism, and therefore, the A layer and the B layer of the intermediate laminated portion are theoretically placed on the front surface of the Al ₆₀ Cr ₃₇ Si ₃ target. when _approached, a nitride of Al _{60 Cr} 37 Si ₃ target component is _coated, when the substrate holder is approached _{Ti 100} target _front, a nitride of _{Ti 100} target component is to be coated. However, it is actually a layer in which an Al ₆₀ Cr ₃₇ Si ₃ target component and a Ti ₁₀₀ target component are mixed. This is because a film coated on a substrate with a layer thickness of several nanometers is such that the mutual diffusion of both metal components occurs between the layers after the next several nanometers of layer is deposited or during the deposition. Because it is. Since the interlayer bond by this interdiffusion is coated with the interlayer bond strength and heat resistance, excellent wear resistance is exhibited.

(Example 2)
Using substantially the same method as in Example 1, a hard film was coated using various target materials, and evaluation of the film and evaluation when the hard film was applied to a cutting tool were performed.

The composition of each layer of the intermediate laminated part was determined by the same measurement as that of TEM-EDS in Example 1. Confirmation of the lamination period was measured from a cross-sectional STEM image. The hardness, elastic modulus, and elastic recovery rate of the intermediate laminated part are measured by using a sample whose sample cross section is mirror-polished in the direction of 5 degrees. By nanoindentation, the indentation load is 49 mN, the maximum load holding time is 1 second, and the load load removal step. Ten points were measured at 0.49 mN, and the average value was obtained . The composition of the lowermost layer and the uppermost layer is also possible by electron probe microanalyzer (EPMA) analysis, energy dispersive X-ray spectroscopy (EDX) analysis, EDS analysis with transmission electron microscope, electron energy loss spectroscopy (EELS) analysis Furthermore, it can be determined comprehensively by depth direction analysis such as Rutherford backscattering (RBS) analysis method, electron spectroscopy (XPS) analysis method, AES analysis method and the like. As a tool used for the evaluation, a high-speed steel φ6 mm drill (cutting evaluation 1) and a cemented carbide two-blade ball end mill (cutting evaluation 2) were used. The film forming conditions for each sample are in accordance with Example 1 unless otherwise specified. Cutting evaluation conditions are

(Evaluation conditions for cutting evaluation 1)
Work material: Alloy steel, SCM440: HRC30
Tool rotation speed: 3200 rotations / minute Feed amount per rotation: 0.15 mm
Machining depth: 15 mm, blind hole Machining method: water-soluble cutting fluid, external lubrication Life judgment: Number of holes until cutting becomes impossible, but rounded down to less than 100 holes (evaluation conditions for cutting evaluation 2)
Work material: Martensitic stainless steel (HRC52)
Tool rotation speed: 20000 rotation / min Table feed rate: 4000 m / min Cutting depth: 0.4 mm in the axial direction, 0.2 mm pick feed
Machining method: Dry cutting Life judgment: Cutting length until maximum wear width reaches 0.1mm, but rounded down to less than 10m

Invention Example 1 was excellent in wear resistance. Invention Example 3 shows a case where the lamination period of the intermediate laminated part is in the range of 0.5 nm to 10 nm. The hardness of the intermediate laminated part was high and the cutting life was excellent. Invention Example 5 shows a case where the intermediate laminated portion is covered with an AlCrSi-based target and a Ti-based target, and the uppermost layer is covered with a TiSi-based target. It was a preferred form because of its wear resistance. In Example 6 of the present invention, the uppermost layer is a Ti (CN) layer having a thickness of 50 nm, and a sputtering evaporation source and an AIP evaporation source are simultaneously operated immediately below, thereby forming a nano-order laminated film of Ti (CN) and MoS _{2 to} a thickness of 150 nm. The case where it coat | covers is shown. This case was particularly suitable for drilling.
Invention Example 7 shows a case where oxygen is contained in the intermediate laminated portion. Excellent wear resistance. The reason for this is that oxygen effectively acts to increase the hardness of the intermediate laminated portion and improve the adhesion between the layers.
Invention Example 8 shows the case where boron is contained in the intermediate laminated portion. In particular, it was effective in increasing the hardness of the intermediate laminated portion, and the cutting life was excellent.
Invention Example 9 shows a case where boron is contained in the intermediate laminated portion and the uppermost layer. It was excellent in chip discharge performance and resulted in excellent cutting life.
Invention Example 11 shows a case where the uppermost layer is titanium nitride and does not contain carbon. Compared to Example 1 of the present invention, when carbon was contained in the uppermost layer, the cutting life was long, which was a preferable form.
Invention Example 12 shows a case where the uppermost layer is a (TiSi) N film, and was particularly excellent in wear resistance.
Invention Examples 14 and 15 show cases where the film thickness ratios of the lowermost layer, the intermediate laminated portion, and the uppermost layer are different from those of Invention Example 1. As a more preferable film thickness configuration, it was preferable that the intermediate laminated portion was the thickest as in the case of the present invention example 1. Furthermore, it is preferable to make the bottom layer thicker than to make the top layer thick.
Invention Example 19 shows a case where the oxygen concentration becomes maximum within a range of less than 100 nm from the hard coating surface. In particular, it was excellent in lubrication characteristics and was a preferred form.
Invention Example 20 shows a case where a hard coating is coated by a sputtering method. Similar to the AIP method, the cutting life was excellent.

  The coating conditions of the comparative example are basically the same processing conditions as the present invention example. Comparative Example 24 shows a case where the sum of the contents of Al and Cr in the A layer of the intermediate laminated portion is 70%. The adhesion strength with the uppermost layer was not sufficient, and the effect of improving the wear resistance was not confirmed. Comparative Example 25 shows a case where the lamination period of the intermediate laminated part is from 105 nm to 150 nm. The upper layer and the intermediate laminate portion were not sufficiently hardened, no interdiffusion was confirmed between the layers of the intermediate laminate portion, and no improvement in wear resistance was confirmed. Comparative Example 26 is a case where the content of Al in the intermediate laminated portion is 15% or less, and shows a case where the peak is composed of only one kind in the range of 40 ° to 45 ° at 2θ in X-ray diffraction. No improvement in wear resistance was found. Comparative Example 27 shows a case where a film containing no Ti is used for the uppermost layer, and Comparative Example 28 shows a case where the uppermost layer is not present. The variation in wear resistance was large, and stable wear resistance was not exhibited. It is hard to say that the wear resistance has been improved.

  Next, the coating of the conventional example was made by referring to the coating conditions described in the literature. Conventional Example 29 is the case where TiN is the lowermost layer and the (TiAl) N-based film is coated on the upper layer, and Conventional Example 30 is a single layer of (TiAl) N film, and Conventional Example 31 is (AlCrSi). In the case of a single layer of N-based coating, the conventional examples 32 and 33 are in the case of a single layer of (AlCr) N-based coating, the conventional example 34 is in the case of a single layer of (AlCrTi) N-based coating, and the conventional example 35 is In the case of a single layer of an (AlCrTiSi) N-based film, the conventional example 36 is an (AlCr) N-based laminated film, and the conventional example 37 is an (AlCr) N-based and (TiAl) N-based laminated film. Conventional Example 38 shows a case of a (TiAl) N-based laminated film. However, all of them were abnormally worn during the cutting process, and their wear resistance was not sufficient.

FIG. 1 shows a schematic diagram of a cross section of a hard coating of an example of the present invention. FIG. 2 is a schematic view of a film forming apparatus according to an example of the present invention. FIG. 3 shows an X-ray diffraction result of the intermediate laminated portion of Example 1 of the present invention. FIG. 4 shows a cross-sectional STEM image of the intermediate laminated portion of Example 1 of the present invention. FIG. 5 shows a limited field diffraction image of the intermediate laminated portion of Example 1 of the present invention. FIG. 6 shows an enlarged image of FIG.

Explanation of symbols

1: target material 2: target material 3: decompression container 4: evaporation source 5: evaporation source 6: evaporation source 7: evaporation source 8: substrate holder 9: substrate 10: rotating mechanism

Claims (1)

In the hard film covering member formed by covering the base surface with the lowermost layer, the intermediate laminated portion and the uppermost layer,
Intermediate laminate portion, composition of the metal component _{(Al W Cr X Ti Y Si} Z) ( where, in atomic%, W + X + Y + Z = 100.) Nitride represented by, borides, carbides and oxides Layers A and B made of either or their solid solution or mixture are alternately laminated in the layer thickness direction,
The A layer and the B layer are at least Al, Cr, and Ti interdiffusion layers, and the composition of the A layer is 70% <W + X <100, 45 ≦ W ≦ 65, 25 ≦ X ≦ 35, 0 <Y ≦ 10 in atomic percent. And 0 <Z ≦ 10, and the composition of the B layer is represented by atomic percent 0 <W ≦ 10, 0 <X ≦ 10, 86.09 <Y <100 and 0 <Z <30.
The uppermost layer is Ti or a nitride and carbonitride of Ti and Si.