JP5267365B2 - Surface coated cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool having a coating film for reducing any crater wear and imparting high wear resistance. <P>SOLUTION: The surface-coated cutting tool includes one or more layers, and at least one layer out of the layers is a Y/Si added titanium zirconium layer containing a first compound indicated by the chemical formula Ti<SB>1-X</SB>Zr<SB>X</SB>M<SB>&alpha;</SB>Z<SB>&beta;</SB>(where M denotes at least one of Y and Si; X, &alpha;, &beta; denote atomic ratio, respectively, X satisfies 0.2&le;X&le;0.6, &alpha; satisfies 0.02&le;&alpha;&le;0.2, and &beta; satisfies 0.1&le;&beta;&le;2; Z denotes at least one element selected from the group consisting of oxygen, carbon and nitrogen.) The first compound has a crystalline structure in which the ratio B/A of the peak intensity B of (200) plane to the peak intensity A of (111) plane in X-ray diffraction satisfies 0&le;B/A&le;1. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a surface-coated cutting tool comprising a substrate and a coating formed on the substrate.

  Surface-coated cutting tools used to cut various work materials can improve the surface wear resistance of hard substrates such as WC-base cemented carbide, cermet, high-speed steel, etc. For the purpose of improving the protective function, the surface has been coated with a hard coating such as TiN, TiCN, TiAlN or the like. In particular, since a coating made of TiAlN exhibits excellent wear resistance, it is widely used as a coating for such surface-coated cutting tools in place of a coating made of titanium nitride, carbide, carbonitride, or the like.

  However, the life of cutting tools is much shorter than before due to the diversification of work materials and the need for high-speed cutting to improve processing efficiency. Furthermore, as a recent trend of cutting tools, there is a tendency that dry processing (dry processing) without using a cutting fluid is required from the viewpoint of global environmental conservation.

  For this reason, the characteristics required for cutting tools are becoming increasingly sophisticated, and various advanced characteristics are also required for the coating of surface-coated cutting tools.

As an attempt to meet such a demand, for example, _a hard coating made of a nitride or carbonitride of (Ti _a Al _b Zr _c ) has been proposed (where 0 <a ≦ 0.5, 0 <b ≦ 0.5, 0.01 ≦ c ≦ 0.5 (a, b, and c represent atomic ratios of Ti, Al, and Zr, respectively) (Patent Document 1) In this proposal, Ti and Ti are used as components of the film. By mixing Zr with Al, it is said that the residual stress of the film can be reduced and the thickness of the film can be increased.

  However, in this proposal, it is difficult to prevent crater wear (a rake face wear phenomenon) due to Al since Al is included as an essential component as a coating.

JP-A-9-323204

  The present invention has been made in view of the current situation as described above, and an object of the present invention is to provide a surface-coated cutting tool having a coating capable of reducing crater wear and imparting high wear resistance. Is to provide.

The surface-coated cutting tool of the present invention includes one or more layers, and at least one of the layers has the chemical formula Ti _1-X Zr _X M _α Z _β (where M is at least one of Y and Si, X , Α, and β each represent an atomic ratio, X is 0.2 ≦ X ≦ 0.6, α is 0.02 ≦ α ≦ 0.2, and β is 0.1 ≦ β ≦ 2. , Z represents at least one element selected from the group consisting of oxygen, carbon, and nitrogen.) And a Y / Si-added titanium zirconium layer containing a first compound represented by the following formula: It has a crystal structure in which the ratio B / A between the peak intensity A of the (111) plane and the peak intensity B of the (200) plane in diffraction is 0 ≦ B / A ≦ 1.

_{X in the} chemical formula Ti _1-X Zr _X M _α Z _β is preferably 0.35 ≦ X ≦ 0.5.

  The first compound preferably has a crystal grain size of 0.1 nm to 200 nm.

  The Y / Si-added titanium zirconium layer is formed by laminating one or more first layers including the first compound and a second layer including the second compound, and the second compound includes Si And at least one element selected from the group consisting of Cr, Al, Ti, Hf, Ta, Nb, and V, and at least one element selected from the group consisting of boron, oxygen, carbon, and nitrogen It is preferable.

  The first layer preferably has a thickness of 0.5 nm to 200 nm, and the second layer preferably has a thickness of 0.5 nm to 200 nm.

  In the surface-coated cutting tool of the present invention, a base layer is formed on a substrate as a coating, and a Y / Si-added titanium zirconium layer is formed on the base layer. The base layer includes Ti, boron, oxygen, and the like. It is preferable to include a third compound containing at least one element selected from the group consisting of carbon, and nitrogen.

  The Y / Si-added titanium zirconium layer preferably has a thickness of 0.3 μm or more and 10 μm or less.

  The surface-coated cutting tool of the present invention can reduce crater wear and provide high wear resistance.

Hereinafter, the present invention will be described in more detail.
<Surface coated cutting tool>
The surface-coated cutting tool of the present invention comprises a substrate and a film formed on the substrate. The surface-coated cutting tool of the present invention having such a configuration is, for example, a drill, end mill, milling or turning cutting edge replaceable cutting tip, metal saw, gear cutting tool, reamer, tap, or pin shaft milling of a crankshaft. It can be used extremely useful as a chip for an automobile. And the surface-coated cutting tool of the present invention is a drill for heat-resistant alloy processing such as Ti alloy processing or Inconel alloy, end mill, milling processing or cutting edge replacement type cutting tip for turning, metal saw, gear cutting tool, reamer, It can be particularly useful as a tap or the like.

<Base material>
As the base material of the surface-coated cutting tool of the present invention, a conventionally known material known as such a cutting tool base material can be used without 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 mentioned as examples of such a substrate. When a cemented carbide is used as such a base material, the effect of the present invention is exhibited even if such a cemented carbide contains an abnormal phase called free carbon or η phase in the structure.

  In addition, these base materials may have a modified surface. For example, in the case of cemented carbide, a de-β layer may be formed on the surface, or in the case of cermet, a surface hardened layer may be formed, and even if the surface is modified in this way, The effect is shown.

<Coating>
The coating film formed on the base material of the surface-coated cutting tool of the present invention includes one or more layers. And at least 1 layer is a Y / Si addition zirconium titanium layer containing the 1st compound explained in full detail below among those layers. As long as the Y / Si-added zirconium titanium layer is included, the coating of the present invention may further include other layers. In addition, the film of this invention is not restricted only to what coat | covers the whole surface on a base material, The aspect in which the film is partially formed is included.

  The total thickness of such a coating (the total thickness when two or more layers are formed) is preferably 0.3 μm or more and 15 μm or less, more preferably the upper limit is 10 μm or less, and further preferably 6 μm. Hereinafter, the lower limit is 0.5 μm or more, more preferably 1 μm or more. If the thickness is less than 0.3 μm, the effect of improving various properties such as wear resistance may not be sufficiently exhibited. If the thickness exceeds 15 μm, the residual stress may increase and the adhesion to the substrate may decrease. . In addition, as a measuring method of a film thickness, it can obtain | require by cut | disconnecting a cutting tool and observing the cross section using SEM (scanning electron microscope). Hereinafter, the coating will be described in more detail.

<Y / Si-added zirconium titanium layer>
The Y / Si-added zirconium titanium layer of the present invention has a chemical formula Ti _1-X Zr _X M _α Z _β (where M is at least one of Y and Si, X, α, and β each represents an atomic ratio, and X is 0 .2 ≦ X ≦ 0.6, α is 0.02 ≦ α ≦ 0.2, β is 0.1 ≦ β ≦ 2, and Z is selected from the group consisting of oxygen, carbon, and nitrogen. At least one kind of element. Such a first compound exhibits higher hardness than a compound having a structure not containing Zr. This is probably due to the fact that in the crystal lattice of the first compound, Zr is mixed as an interstitial type or a substitution type with respect to Ti at a specific site, so that the crystal lattice is distorted and the crystal grains themselves become finer. Is done.

  Also, by adding at least one of Y (yttrium) and Si, the phase transformation of the Zr oxide layer is suppressed, and a stable oxide layer is formed even at high temperatures, thereby improving the wear resistance during cutting. Can do. It is known that the crystal structure of Zr oxide changes reversibly with temperature, and thermal fatigue occurs, and volume expansion or contraction due to change in crystal structure also causes oxide layer peeling, which is resistant to resistance. Abrasion was low. By adding at least one of Y (yttrium) and Si, this crystal structure change can be suppressed, and wear resistance can be improved.

  The Y / Si-added zirconium titanium layer of the present invention can be composed of only the first compound except for inevitable impurities. However, it may contain other components (elements) as described later, and may be formed by laminating a layer containing a first compound and a layer containing another compound as described later. good.

  Note that such a Y / Si-added zirconium titanium layer is formed with the first compound and the secondary compound (formed simultaneously with the formation of the first compound or formed over time after the formation). It may also contain a chemical compound. Such a secondary compound is contained in a small amount with respect to the first compound, and examples thereof include a compound composed of Ti and Z in the chemical formula, a compound composed of Zr and Z in the chemical formula, Ti simple substance and Zr simple substance can also be mentioned.

<First compound>
The first compound contained in the Y / Si-added zirconium titanium layer has the chemical formula Ti _1-X Zr _X M _α Z _β (where Y (yttrium) and at least one of Si, X, α, and β each have an atomic ratio. X is 0.2 ≦ X ≦ 0.6, α is 0.02 ≦ α ≦ 0.2, β is 0.1 ≦ β ≦ 2, and Z is oxygen, carbon, and nitrogen And at least one element selected from the group consisting of: In the above chemical formula, the atomic ratio X is preferably 0.35 ≦ X ≦ 0.5, the lower limit of X is more preferably 0.4, still more preferably 0.44, and the upper limit is more preferably 0. .49, more preferably 0.47. When the atomic ratio X exceeds 0.6, excellent wear resistance is not exhibited.

  The constituent element M of the first compound is at least one of Y and Si. That is, both of these elements (Y and Si) or alone (Y or Si) are added into the film. Α represents an atomic ratio of the atomic weight of these elements added to the total atomic weight of Ti and Zr, and 0.02 ≦ α ≦ 0.2. The lower limit is more preferably 0.03, still more preferably 0.04, and the upper limit is more preferably 0.15, and even more preferably 0.12. When at least one of Y and Si is added in the above atomic ratio, the crystal transformation of the Zr oxide is suppressed, the phase transformation of the Zr oxide layer is suppressed, and a stable oxide layer is formed even at a high temperature. The wear resistance at the time can be improved. Zr oxide is known to change its crystal structure reversibly with temperature, and it is resistant to thermal fatigue as well as volumetric expansion or contraction due to change in crystal structure, which causes the oxide layer to peel off. Abrasion was low. By adding at least one of Y (yttrium) and Si, this crystal structure change can be suppressed and the wear resistance can be improved.

  As is apparent from the chemical formula as described above, since the first compound of the present invention does not contain Al as a constituent element in principle, crater wear can be reduced extremely effectively. Moreover, by including Zr in the above atomic ratio, the coating hardness is greatly increased, and the crater wear can be drastically reduced by acting synergistically. Conceivable.

  In the above chemical formula, Z represents at least one element selected from the group consisting of oxygen, carbon, and nitrogen. That is, Z may be composed of these elements alone or in combination of two or more elements. When two or more elements are combined, the atomic ratio of each element is not particularly limited, but when nitrogen is included, nitrogen occupies these constituent elements (that is, with respect to β in the above chemical formula). The atomic ratio is preferably 50% or more.

  Further, the atomic ratio β is not particularly limited as long as 0.1 ≦ β ≦ 2, but more preferably 0.4 ≦ β ≦ 1.8. When β is less than 0.1, the wear resistance is lowered, which is not preferable. On the other hand, if β exceeds 2, the wear resistance is lowered, which is not preferable. In addition, when Z is comprised by 2 or more types of elements as mentioned above, atomic ratio (beta) shall show atomic ratio with respect to the total atomic weight of Ti and Zr of the total amount of those elements.

<Crystal structure of the first compound>
The first compound has a crystal structure in which the ratio B / A between the peak intensity A of the (111) plane and the peak intensity B of the (200) plane in X-ray diffraction satisfies 0 ≦ B / A ≦ 1. And That is, the crystal structure thus defined indicates that the orientation of the first compound of the present invention is not (200) preferred orientation but (111) preferred orientation. This fact is supported by the ratio B / A of the non-oriented TiN powder being 1.3 and the ratio B / A of the non-oriented CrN powder being 1.25. This is because if the first compound of the present invention is non-oriented, the ratio B / A is naturally expected to show a value in the range of 1.25 to 1.3.

  The upper limit of the ratio B / A is more preferably 0.8, still more preferably 0.5, and the lower limit is ideally 0.

  As described above, when the crystal structure of the first compound exhibits the (111) preferential orientation, extremely high wear resistance is exhibited. In the present invention, it has been found that the (111) preferential orientation has extremely high lubricity as compared with the case of the (200) preferential orientation, and it is considered that the wear resistance during cutting is thereby improved. It is done.

  Furthermore, the first compound of the present invention preferably has a crystal grain size of 0.1 nm or more and 200 nm or less, more preferably the upper limit is 100 nm, and even more preferably 60 nm. When the crystal grain size is less than 0.1 nm, it cannot be distinguished from the amorphous state, and when it exceeds 200 nm, the cutting performance may be deteriorated.

  Thus, it is preferable that the crystal grain size of the first compound of the present invention is as small as the above-mentioned range, and the smaller the size, the more the densification is promoted and the toughness is improved and the cutting performance is improved. Will be. Therefore, the smaller the crystal grain size, the better. However, if the crystal grain size is less than 0.1 nm as described above, the crystal state cannot be maintained and an amorphous state is obtained, so that the cutting performance is deteriorated.

  In addition, such a crystal grain diameter means the average value which can be calculated | required from the half value width of the peak resulting from the (111) plane in X-ray diffraction.

<Laminated structure of Y / Si-added zirconium titanium layer>
The Y / Si-added zirconium titanium layer of the present invention is formed by laminating one or more layers each including a first layer containing the first compound and a second layer containing the second compound. The second compound is selected from the group consisting of at least one element selected from the group consisting of Si, Cr, Al, Ti, Hf, Ta, Nb, and V, and boron, oxygen, carbon, and nitrogen. And at least one element. Such a first layer preferably has a thickness of 0.5 nm to 200 nm, and the second layer also preferably has a thickness of 0.5 nm to 200 nm.

  Here, the second compound is composed of boron, oxygen, carbon, and nitrogen with respect to at least one element selected from the group consisting of Si, Cr, Al, Ti, Hf, Ta, Nb, and V. It is preferable to contain at least one element selected from the group in an atomic ratio of 0.1 or more and 2 or less. By setting the atomic ratio within this range, the following excellent effects are exhibited. In addition, when two or more different elements among Si, Cr, Al, Ti, Hf, Ta, Nb, and V are included, the atomic ratio between the elements is as long as the total amount satisfies the atomic ratio in the above range. Is not particularly limited. Similarly, when two or more different elements of boron, oxygen, carbon, and nitrogen are included, the atomic ratio between the elements is not particularly limited.

  By adopting the laminated structure as described above, the following excellent effects are exhibited. That is, since the second compound is excellent in oxidation resistance, in addition to the action of reducing crater wear and the action of improving wear resistance, the Y / Si-added zirconium titanium layer as a whole exhibits excellent oxidation resistance. In addition, by laminating two layers having different compositions in this way, it is possible to extremely effectively prevent cracks from progressing in the thickness direction of the film, and wear phenomenon caused by film destruction due to the progress of the cracks can be suppressed. As a result, the wear resistance can be further improved.

  Here, as described above, the first layer preferably has a thickness of 0.5 nm to 200 nm, and similarly, the second layer preferably has a thickness of 0.5 nm to 200 nm. This is because having a thickness in this range exhibits particularly excellent wear resistance during cutting. And as for each thickness of the said 1st layer and the 2nd layer, More preferably, the upper limit is 100 nm, More preferably, it is 50 nm, The lower limit is more preferably 1 nm. It is difficult to form each layer with a thickness of less than 0.5 nm. When the thickness exceeds 200 nm, the above-described excellent effects may not be shown. Particularly preferably, the total thickness of only the first layer is 0.3 μm or more and 10 μm or less, and more preferably 0.7 μm or more and 5 μm or less. By making the total thickness of only the first layer within these ranges, the above effect is most effectively exhibited. As long as the total thickness of only the first layer falls within such a range, the total thickness of only the second layer is not particularly limited, but a thickness of 1 μm or more and 10 μm or less is usually sufficient. The thicknesses of the first layer and the second layer laminated in this way may be approximately equal or different.

  Note that the laminated structure indicates that the first layer and the second layer are formed by laminating one or more layers, and more preferably, the first layer and the second layer are respectively formed. It is preferable that a plurality of layers are stacked alternately one above the other. In such a laminated structure, the lowermost layer and the uppermost layer may be formed of either the first layer or the second layer. In addition, the number of stacked layers is not particularly limited, but each layer may be 1 layer or more and 8000 layers or less, more preferably 20 layers or more and 5000 layers or less.

<Thickness of Y / Si-added zirconium titanium layer>
The Y / Si-added zirconium titanium layer of the present invention preferably has a thickness of 0.3 μm or more and 10 μm or less. More preferably, the upper limit is 8 μm or less, more preferably 7 μm or less, particularly preferably 6 μm or less, and the lower limit is more preferably 0.7 μm or more, and further preferably 1 μm or more.

  When the thickness is 0.3 μm or more, crater wear can be further reduced. Conventionally, it is known that the wear resistance is improved as the thickness of the cutting tool increases. However, as a result of considering the followability of the cutting edge shape and the like, it has been found that a film having excellent wear resistance and toughness can be obtained when the above is preferably 10 μm or less, more preferably 7 μm or less. The above-described effect is particularly excellent when the thickness is 1 μm or more and 6 μm or less.

<Underlayer>
In the surface-coated cutting tool of the present invention, a base layer may be formed on a base material as a coating, and the Y / Si-added zirconium titanium layer may be formed on the base layer. A third compound containing Ti and at least one element selected from the group consisting of boron, oxygen, carbon, and nitrogen can be included. This third compound is excellent in adhesion to the base material. Therefore, the base layer is formed on the base material so as to be in contact with the base material, and the Y / Si-added zirconium titanium layer is formed on the base layer. In this case, these films are formed on the substrate with high adhesion as a whole.

  Examples of such a third compound include TiN, TiAlN, TiC, TiCN, TiBN, TiNO, TiCrN, TiCrNO, and TiWN. In addition, when atomic ratio is not prescribed | regulated especially in these chemical formulas, the atomic ratio of each element does not necessarily become an equivalent ratio, but all the conventionally well-known atomic ratio shall be included. For example, when TiN is described, the atomic ratio of Ti and N includes 1: 1, and includes 2: 1, 1: 0.95, 1: 0.9, etc. (otherwise, unless otherwise specified) Same for describing chemical formula). That is, the atomic ratio between Ti and at least one element selected from the group consisting of boron, oxygen, carbon, and nitrogen (including the atomic ratio of that element when other (metal) elements are included in addition to Ti, In the case where two or more kinds of boron, oxygen, carbon, or nitrogen are contained, the atomic ratio between these elements is also not particularly limited, and all conventionally known atomic ratios are included.

  The underlayer as described above preferably has a thickness of 0.05 μm to 2 μm, more preferably 0.1 μm to 1 μm. In addition, such an underlayer can be composed of one layer, or can be composed of two or more layers (when composed of two or more layers, the total thickness is within the above range). ).

<Other layers>
The film of the present invention may further contain one or more layers other than the Y / Si-added zirconium titanium layer and the underlayer as described above. For example, such other layers can be formed between the underlayer and the Y / Si-added zirconium titanium layer, or can be formed on the Y / Si-added zirconium titanium layer. By forming such other layers, the effect of the present invention of reducing crater wear and imparting high wear resistance can be further improved, or lubricity can be imparted. The effect that welding can be suppressed can also be achieved.

Examples of the compound constituting such another layer include oxides such as Al ₂ O ₃ , siliconitrides such as TiSiN, carbonitrides such as TiCN, and the like. Note that such other layers preferably have a thickness of 0.05 μm to 5 μm, more preferably 0.1 μm to 2 μm.

<Manufacturing method>
Since the coating of the present invention, particularly the Y / Si-added zirconium titanium layer, needs to be composed of a highly crystalline compound as described above, the coating of the present invention is composed of such a highly crystalline compound. It is preferable that the film is formed by a simple film forming process. Therefore, it is desirable that the film of the present invention is formed by physical vapor deposition (PVD method). Examples of such physical vapor deposition include balanced magnetron sputtering, unbalanced magnetron sputtering, arc ion plating, and combinations of these. Even when the Y / Si-added zirconium titanium layer is formed in the above laminated structure, it can be formed by a conventionally known method under these physical vapor deposition methods.

  In particular, specific conditions for suitably forming the above-described Y / Si-added zirconium titanium layer are as follows. That is, when the arc ion plating method is adopted, a target containing each corresponding element at an appropriate blending ratio is set in an arc evaporation source so as to obtain a first compound having a desired structure, and a substrate (base material) ) By setting the temperature to 400 to 700 ° C. and the reaction gas pressure in the apparatus to 2.0 to 6.0 Pa, and selecting one or more gases from among nitrogen, methane, oxygen, etc. as the reaction gas Is introduced. Then, while maintaining the substrate (negative) bias voltage at −60 V to −200 V, an arc current of 50 to 120 A is supplied to the cathode electrode to generate metal ions and the like from the arc evaporation source, thereby adding Y / Si added zirconium. A titanium layer can be formed.

When the unbalanced magnetron sputtering method is adopted, the substrate (base material) temperature is set to 400 to 600 ° C., the reaction gas pressure in the apparatus is set to 300 mPa to 800 mPa, and the reaction gas corresponding to the desired first compound For example, one or more gases are selected from nitrogen, acetylene, and oxygen (introducing the reaction gas, the ratio of the rare gas / reaction gas is preferably set to 1 to 5). ). Then, while maintaining the substrate (negative) bias voltage at 0 V to -90 V (the higher the bias voltage is, the more the orientation of the crystal structure of the first compound tends to improve), 0.12 is applied to the target. it is possible to form the Y / Si added zirconium titanium layer by generating a power density of ~0.3W / mm ^2.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In addition, the chemical composition (composition of the compound) of each layer constituting each of the following films is confirmed by an energy dispersive X-ray fluorescence spectrometer (SEM-EDX) attached to the secondary electron microscope, and the thickness of each layer is determined by the thickness of the film. The cross section was confirmed by observing with a secondary electron microscope (SEM).

  In this example, the coating film formed on the substrate was formed by the cathodic arc ion plating method or the sputtering method as follows.

<Cathode-type arc ion plating (AIP) method>
First, as a base material, a cutting tip having a grade of P30 (JIS B 4053-1998) cemented carbide and a shape of SNGN120408 (JIS B 4121-1998) was prepared, washed, and then a cathodic arc. The substrate was set in the ion plating apparatus (deposition apparatus) at the substrate mounting position. As such a film forming apparatus, a conventionally known apparatus can be used without any particular limitation.

And while reducing the inside of this apparatus to 1x10 <^-4> Pa or less with a vacuum pump, the temperature of the said base material was heated to 650 degreeC with the heater installed in this apparatus, and it hold | maintained for 1 hour.

  Next, argon gas was introduced to maintain the pressure in the apparatus at 3.0 Pa, the substrate (base material) bias voltage was gradually increased to −1500 V, and the surface of the base material was cleaned for 15 minutes. Thereafter, argon gas was exhausted.

  Next, each of the corresponding elements is included so that the chemical composition of the coating film (that is, the Y / Si-added zirconium titanium layer made of the first compound) formed on the substrate surface is as shown in Table 1 below. However, each target was set in a raw material evaporation source (an arc evaporation source). The substrate (base material) temperature is set to 550 to 650 ° C., the reaction gas pressure in the apparatus is set to 4.0 Pa, and the reaction gas corresponding to the chemical composition shown in Table 1 is selected from among nitrogen, methane, and oxygen. This was introduced by selecting the above gas. Then, while maintaining the substrate bias voltage at −80 V, an arc current of 50 to 120 A was supplied to the cathode electrode, and metal ions and the like were generated from the arc evaporation source to form a Y / Si-added zirconium titanium layer.

  That is, a metal ion, a metal element, or a cluster generated from an arc evaporation source reacts with the reaction gas in a plasma atmosphere, whereby a Y / Si-added zirconium titanium layer (that is, the first compound) is formed on the substrate. It will be formed (deposited). As the reaction gas, nitrogen is selected when the final product (first compound) is a nitride, and methane (a hydrocarbon gas such as acetylene is not limited to methane, but is not limited to methane). And argon gas can be selected as the atmospheric gas (for reactive gas partial pressure control), and in the case of oxide, argon gas can be selected as the oxygen and atmospheric gas (for reactive gas partial pressure control). In the case of other carbonitrides or nitride oxides, two or more kinds of reaction gases were selected and used based on the above example.

For Example 1 and Example 2, an alloy target of Ti—Zr—Y was used as the metal source. For Example 3, Example 4, Example 17, and Example 18, a Ti—Zr—Y ₂ O ₃ alloy target was used as the metal source. In Example 3, Example 4, Example 17, and Example 18, films were formed in a nitrogen atmosphere, but oxygen contained in Y ₂ O ₃ was contained in the films. For Example 5 and Example 6, a Ti—Zr—Si alloy target was used. For Example 7 and Example 8, a Ti—Zr—Y ₂ O ₃ —Si alloy target was used.

  And when the thickness described in Table 1 is reached, the current supplied to the arc evaporation source is stopped, and after cooling, the inside of the apparatus is opened to the atmosphere, and then the surface-coated cutting tool with the coating formed on the substrate is used. By taking out from the apparatus, the surface-coated cutting tool of the present invention was produced. In the section of “Production method” in Table 1, the surface-coated cutting tool produced by this cathodic arc ion plating method was indicated as “AIP”.

<Sputtering (SP) method>
First, as the base material, the same base material as that used in the above-described cathodic arc ion plating method was prepared, washed, and then set at the substrate mounting position in the sputtering apparatus (film forming apparatus). Next, each of the corresponding elements is included so that the chemical composition of the coating film (that is, the Y / Si-added zirconium titanium layer made of the first compound) formed on the substrate surface is as shown in Table 1 below. Each target was set (Examples 9 to 16). The target may be an alloy target, or a single metal target may be divided so as to have the above chemical composition. As such a film forming apparatus, a conventionally known apparatus can be used without any particular limitation.

And while reducing the inside of this apparatus to 1x10 <^-4> Pa or less with a vacuum pump, the temperature of the said base material was heated to 500 degreeC or more with the heater installed in this apparatus, and it hold | maintained for 1 hour.

  Next, argon gas was introduced to maintain the pressure in the apparatus at 500 mPa to 650 mPa, the substrate (base material) bias voltage was gradually increased to −600 V, and the surface of the base material was cleaned for 30 minutes. Subsequently, the substrate bias voltage was set to −350 V, and the substrate surface was further cleaned for 60 minutes using a holocathode gas activation source. Thereafter, argon gas was exhausted.

  Next, the substrate (base material) temperature is set to 500 to 600 ° C., the reaction gas pressure in the apparatus is set to 500 mPa to 650 mPa, and the reaction gas corresponding to the chemical composition shown in Table 1 is selected from among nitrogen, acetylene, and oxygen. This was introduced by selecting one or more gases from When introducing the reaction gas, the flow rate ratio of the rare gas / reaction gas was set to 1-5.

Then, while maintaining the substrate bias voltage at −90 V, a power density of 0.12 to 0.3 W / mm ² is generated on the target, thereby adding a coating (that is, adding Y / Si made of the first compound) on the substrate. Zirconium titanium layer) was formed. The power density supplied to the target was stopped when the coating reached the thickness shown in Table 1.

  A DC pulse method was used as the substrate bias power source and the target supply power source. The substrate bias power supply supplies positive and negative voltages at a frequency of 350 kHz, and the time for supplying the positive voltage per cycle is 500 ns. The frequency of the power supply for target supply was 50 kHz, and the supply time of positive and negative voltages per cycle was half each.

  The reaction gas was always mixed with a rare gas (preferably, but not limited to argon). The selection criteria for the reaction gas are the same as those for the cathode arc ion plating method. When boron was included in the chemical composition, a target containing a desired amount of boron element in advance was used.

Thus, the surface-coated cutting tool of the present invention was produced. In addition, in the section of “Production method” in Table 1, the surface-coated cutting tool produced by this sputtering method (unbalanced magnetron sputtering method) was indicated as “SP”. For Example 9 and Example 10, an alloy target of Ti—Zr—Y was used as the metal source. For Example 11 and Example 12, a Ti—Zr—Y ₂ O ₃ alloy target was used as the metal source. In Example 11 and Example 12, film formation was performed in a nitrogen atmosphere, but the film contained oxygen derived from Y ₂ O ₃ . For Example 13 and Example 14, a Ti—Zr—Si alloy target was used. For Example 15 and Example 16, a Ti—Zr—Y ₂ O ₃ —Si alloy target was used.

<Laminated structure>
In the section of “Laminated structure” in Table 1, when the Y / Si-added zirconium titanium layer is formed by laminating the first layer and the second layer described above, it is denoted as “present”, and When it is not a structure (that is, in the case of a single layer), it is described as “none”.

  In the case where such a laminated structure is formed by the cathodic arc ion plating method, the target 1 for forming the first layer (the composition is set to a composition that can obtain the first compound shown in Table 1) and the first layer A target 2 for forming two layers (the composition is set to a composition that can obtain the second compound shown in Table 3) is set on the inner wall of the apparatus at the same height, and an intermediate point between the two targets (approximately the center of the apparatus). ) Was set on the substrate. Then, by rotating the base material while evaporating both the target 1 and the target 2, a first layer is formed when the base material is located in front of the target 1, and when the base material is located in front of the target 2, the first layer is formed. Two layers were formed. Although a laminated structure can be formed in this way, the conditions for evaporating the target were the same as the above conditions for forming the Y / Si-added zirconium titanium layer.

  When such a laminated structure is formed by a sputtering method, the base material, the target 1 and the target 2 are arranged in the apparatus in the same manner as in the case of the cathode arc ion plating method, and Y / By adopting the same conditions as the sputtering conditions for forming the Si-added zirconium titanium layer, a laminated structure could be formed.

  Details of the laminated structure thus obtained are shown in Table 3. In Table 3, the first layer is composed of the first compound described in Table 1, and the second layer is composed of the second compound described in Table 3. And each layer was laminated | stacked alternately by the thickness described in Table 3, and the Y / Si addition zirconium titanium layer of the thickness described in Table 1 was formed. In addition, the lowest layer of each laminated structure was the first layer, and the uppermost layer was the second layer.

As described above, the surface-coated cutting tools of Examples 1 to 18 having the configurations described in Table 1 and Table 3 were manufactured. The surface-coated cutting tools of these examples comprise a substrate and a coating formed on the substrate, the coating having the chemical formula Ti _1-X Zr _X M _α Z _β (where M is At least one of Y and Si, X, α, and β each represent an atomic ratio, X is 0.2 ≦ X ≦ 0.6, α is 0.02 ≦ α ≦ 0.2, and β is 0.1 ≦ β ≦ 2, and Z represents at least one element selected from the group consisting of oxygen, carbon, and nitrogen. As will be confirmed below, this first compound is a crystal in which the ratio B / A between the peak intensity A of the (111) plane and the peak intensity B of the (200) plane in X-ray diffraction is 0 ≦ B / A ≦ 1. It was characterized by having a structure.

<Confirmation of crystal structure>
For the surface-coated cutting tools of Examples 1 to 18 manufactured as described above, by performing X-ray diffraction by the θ-2θ method, the crystal structure of the Y / Si-added zirconium titanium layer (that is, the first compound), That is, the ratio B / A between the peak intensity A of the (111) plane and the peak intensity B of the (200) plane, the crystal grain size, the plane spacing of the (111) plane, and the plane spacing of the (200) plane were obtained. . The X-ray was CuKα ray, the crystal grain size (that is, the crystal grain size of the first compound) was calculated from the half width of the (111) plane, and the plane spacing was calculated from the 2θ angle at the point where the peak intensity was maximum. These results are shown in Table 4 below.

<Comparative Examples 1-11>
As Comparative Example 1, a surface-coated cutting tool in which a film made of a compound containing no Zr in the first compound (specifically, TiN) was formed on a substrate was manufactured. Further, as Comparative Example 2, a surface-coated cutting tool in which a film made of TiAlN was formed on a substrate was manufactured. In Comparative Example 3, a film made of a compound having the same composition as the first compound of Example 2 was formed. By changing the bias voltage during film formation to 0 V, the peak intensity of the (111) plane was This is a surface-coated cutting tool that differs from Example 2 in that the ratio B / A between A and the peak intensity B of the (200) plane is 1.13.

  Comparative Example 4 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio X in the chemical formula of the first compound exceeds 0.6. Comparative Example 5 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio X in the chemical formula is less than 0.2. Comparative Example 6 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio α in the chemical formula exceeds 0.2. Comparative Example 7 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio α in the chemical formula is less than 0.04. Comparative Example 8 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio β in the chemical formula of the first compound is less than 0.2.

  Comparative Example 9 is a surface-coated cutting tool obtained in the same manner as in Example 2 except that the atomic ratio β in the above chemical formula exceeds 2 in the first compound. Comparative Examples 10 and 11 are surface-coated cutting tools obtained in the same manner as Comparative Example 4 except that the film thicknesses are different. The physical properties and the like of the surface-coated cutting tools of these comparative examples are shown in Table 2 and Table 4.

<Cutting test>
With respect to the surface-coated cutting tools of Examples 1 to 18 and the surface-coated cutting tools of Comparative Examples 1 to 11 manufactured as described above, flank wear is performed by performing a continuous turning test for 8 minutes under the following cutting conditions. The amount and the amount of crater wear were measured. The smaller the flank wear amount, the better the wear resistance, and the smaller the crater wear amount, the lower the crater wear. The results are shown in Table 5 below.

(Cutting conditions)
Work material: SCM435
Cutting speed: 350 m / min
Cutting depth: 1.5mm
Feed: 0.15 mm / rev.
Dry / Wet: Wet

In Tables 1 and 2, “X”, “α”, “β”, and “Z” are X, α, β, Z in the chemical formula Ti _1-X Zr _X M _α Z _β which is the first compound. Respectively. In Table 3, the numerical value described in the “second compound” section indicates an atomic ratio.

  As is clear from Table 5, the surface-coated cutting tool of the example of the present invention showed superior results in both the reduction of crater wear and the improvement of the wear resistance compared to the surface-coated cutting tool of the comparative example. It is clear that Therefore, the surface-coated cutting tool of the present invention has excellent cutting performance. In addition, the wear resistance of the cutting test is affected by the film thickness, and it can be seen that the wear amount decreases as the film thickness increases. That is, by comparing Examples 3, 17 and 18, when the Y / Si-added titanium zirconium layer containing the first compound in the present invention is provided, the amount of wear can be further reduced as the film thickness increases. Recognize. The superiority of the present invention can be confirmed even when the film thickness is 1 μm or 10 μm by comparing Example 17 with Comparative Example 10 and comparing Example 18 with Comparative Example 11.

  In the above-described embodiments, only the Y / Si-added zirconium titanium layer is formed as a coating on the base material. However, the base layer as described above is formed on the base material, and the base layer is formed on the base layer. A Y / Si-added zirconium titanium layer can also be formed, and the adhesion between the substrate and the coating can be further improved.

  Although the embodiments and examples of the present invention have been described as 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.

Claims (7)

A surface-coated cutting tool comprising a substrate and a coating formed on the substrate,
The coating comprises one or more layers;
At least one of the layers has the chemical formula Ti _1-X Zr _X M _α Z _β (where M is at least one of Y and Si, X, α, and β each represents an atomic ratio, and X is 0.2 ≦ X ≦ 0.6, α is 0.02 ≦ α ≦ 0.2, β is 0.1 ≦ β ≦ 2, and Z is at least selected from the group consisting of oxygen, carbon, and nitrogen A Y / Si-added titanium-zirconium layer containing the first compound represented by 1).
The first compound has a crystal structure in which the ratio B / A between the peak intensity A of the (111) plane and the peak intensity B of the (200) plane in X-ray diffraction satisfies 0 ≦ B / A ≦ 1. A surface-coated cutting tool. The surface-coated cutting tool according to claim 1, wherein the X in the chemical formula Ti _1-X Zr _X M _α Z _β is 0.35 ≦ X ≦ 0.5.   The surface-coated cutting tool according to claim 1 or 2, wherein the first compound has a crystal grain size of 0.1 nm or more and 200 nm or less. The Y / Si-added titanium zirconium layer is formed by laminating one or more layers each including a first layer containing the first compound and a second layer containing a second compound.
The second compound is at least one element selected from the group consisting of Si, Cr, Al, Ti, Hf, Ta, Nb, and V, and at least selected from the group consisting of boron, oxygen, carbon, and nitrogen. The surface-coated cutting tool according to claim 1, comprising one kind of element. The first layer has a thickness of 0.5 nm or more and 200 nm or less,
The surface-coated cutting tool according to claim 4, wherein the second layer has a thickness of 0.5 nm or more and 200 nm or less. In the surface-coated cutting tool, a base layer is formed on the substrate as the coating, and the Y / Si-added titanium zirconium layer is formed on the base layer.
The surface-coated cutting tool according to claim 1, wherein the underlayer includes a third compound containing Ti and at least one element selected from the group consisting of boron, oxygen, carbon, and nitrogen. .   The surface-coated cutting tool according to claim 1, wherein the Y / Si-added titanium zirconium layer has a thickness of 0.3 μm to 10 μm.