JPS6148582B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Technical Field The present invention relates to improvements in alumina-coated cemented carbide tools. (b) Background Art So-called alumina-coated tools, which improve cutting performance by coating cemented carbide with alumina, are widely used as main tools as cutting speeds increase in the market. However, when alumina is directly coated on cemented carbide, there are various problems such as its adhesion. After coating, a method is adopted in which the outer layer is coated with alumina. It is known that the properties of this alumina change depending on the crystal grain size, and fine grained alumina has better performance as a cutting tool. A common method to reduce the grain size of this alumina layer is to slow down the reaction rate at low temperatures and suppress grain growth.
Alumina has a slower growth rate than elements such as TiC, TiN, etc., so coating tools with a fine alumina layer have excellent performance but poor productivity, so productivity is increased at the expense of performance. This is the current situation. (C) Disclosure of the Invention As a result of repeated research in order to provide an alumina-coated tool that fully utilizes the properties of alumina and can be easily manufactured, the present inventors have discovered that amorphous alumina and crystallized alumina can be used as alumina. It was discovered that an alumina film composed of amorphous alumina and crystallized alumina obtained under conditions where amorphous alumina and crystallized alumina are simultaneously produced is fine and dense, and has high productivity, and has developed the present invention. It has been reached. Namely, in an atmosphere of AlCl ₃ , H ₂ , CO ₂ or H ₂ O, plasma chemical vapor deposition at a low temperature of 500 to 900°C or organic compounds of Ti, Zr, or BCl ₃
Amorphous alumina and crystallized alumina are simultaneously produced by chemical vapor deposition in the presence of trace amounts of doping substances such as 0.5 μm
It was discovered that the following fine-grained alumina film grows. In addition, organic compounds such as dimethylamide titanium [Ti(NMe ₂ ) ₄ ], dimethylamide zirconium [Zr(NMe ₂ ) ₄ ], etc. are used as doping agents in the plasma chemical vapor deposition of alumina.
If BCl ₃ or the like is present at a ratio of 0.2 or less to the flow rate of AlCl ₃ , the growth rate of alumina will be significantly faster and productivity will be increased, which is advantageous. The particle size and amount of amorphous alumina in this alumina layer vary depending on the reaction temperature, reaction gas composition, plasma density, and doping amount, but as a tool material, 0.01
It exhibits sufficient performance in the particle size range of ~0.5 μm, and since amorphous alumina has lower hardness than crystallized alumina, it is not preferable to use more than 60% by volume of amorphous alumina because the wear resistance will be poor. Ten
% or less, the alumina particle size is difficult to become fine, so a range of 10 to 60% by volume is appropriate. The amorphous alumina and crystallized alumina of the outer layer can also be produced by physical vapor deposition methods that have a fast growth rate, such as ion plating and sputtering, but it is difficult to obtain a fine and dense film with these physical vapor deposition methods. , those by the above-mentioned chemical vapor deposition method are preferred. The thickness of the alumina layer is preferably 0.5 to 10 μm,
There is no improvement in wear resistance below 0.5 μm, and 10
If it exceeds μm, toughness will be impaired. Regarding the adhesion of the outer layer, since the outer layer contains amorphous alumina, the adhesion to the base is slightly inferior to that of a single layer of crystallized alumina. Therefore, the inner layer includes Ti, V, Cr, Mo,
A combination of carbides, nitrides, carbonitrides, borides, boronitrides, etc. made of one or more of W and Si satisfies the adhesion required as a tool material. Specific examples include TiC, VC, Cr ₇ C ₃ , WC,
_Mo2C , SiC, TiN, _Si3N4 , _TiCN , _TiB2 , Ti
(BN), etc., but for example, TiC and TiN
It can be produced by conventional chemical vapor deposition methods using TiCl ₄ and CH ₄ or N ₂ and H ₂ atmosphere at 1000° C. and 50 Torr. The optimum film thickness is 0.5 to 5 μm. If the thickness is more than 5 μm, the strength as a coating chip decreases.
m or less, plastic deformation of the tool is likely to occur. Therefore, the present invention uses Ti, V, Cr, Mo, W, Si.
an inner layer consisting of one or more of one or more of carbides, nitrides, carbonitrides, borides, and boronitrides, and
The present invention relates to a coated cemented carbide tool, characterized in that it has a coating layer consisting of an outer layer made of alumina made of amorphous alumina and crystallized alumina with a particle size of 0.01 to 0.5 μm. Further, the present invention uses a cemented carbide as a base material, and the surface of the base material contains one or more carbides, nitrides, carbonitrides, borides, and boronitrides of Ti, V, Cr, Mo, W, and Si. coated with a layer of one or more of AlCl ₃ , H ₂ ,
Supercoating consisting of a further coating of amorphous alumina and crystallized alumina with a grain size of 0.01-0.5 μm by plasma-enhanced chemical vapor deposition at 500-900°C in an atmosphere of CO ₂ or H ₂ O. This invention relates to a method for manufacturing hard metal tools. (d) Best Mode for Carrying Out the Invention Example 1 P-30 cemented carbide was coated with TiC as an inner layer to a thickness of 5 μm by chemical vapor deposition, and then heated at 700°C.
Plasma was generated by applying 500 W of high frequency power of 13.56 MHz in 1 volume % AlCl ₃ , 10 volume % CO ₂ , 89 volume % H ₂ gas under 1 torr, and Al ₂ O ₃ C was 0.1μ
It was coated to a thickness of m, 5 μm, and 10 μm. this
When the surface of the Al ₂ O ₃ film was examined using a scanning electron microscope, it was found to be a dense film with a particle size of 0.1 μm, and a weak α-Al ₂ O ₃ peak was observed in X-ray diffraction. For comparison, P-30 cemented carbide coated with 5 μTiC by chemical vapor deposition was coated with 2 μm grain size.
Coating chips coated with Al ₂ O ₃ at thicknesses of 0.1 μm, 5 μm, and 10 μm were prepared. Table 1 shows the results of cutting performance tests conducted on chips of the present invention and comparative examples under the following conditions. Cutting speed 300m/min Feed 0.4m/min Depth of cut 1.5mm Work material SCM3

[Table] When the chips A, B, and C were heat-treated at 1300℃, a stronger α-Al ₂ O ₃ diffraction peak was observed compared to before the heat treatment, and the previously prepared α-Al ₂ O ₃ film was From the relationship between thickness and peak intensity, amorphous Al ₂ O ₃
Calculating the capacity percentage of A is 20%, B is 45%, and C is
It was 60%. Example 2 VC was applied to P-30 cemented carbide in the same manner as in Example 1.
Each thickness of 0.1μm, 5μm, 10μm and Cr ₇ C ₃ 5μ
m as an inner layer, and then apply 1KW, 500W, and 50W of 13.56MHz high frequency power to 0.02μ
Al ₂ O ₃ films with particle sizes of m, 0.1 μm, and 1 μm were coated with a thickness of 3 μm. These chips were heat treated at 1300° C. and the volume percent of amorphous Al ₂ O ₃ was calculated, and these data are summarized in Table 2. For comparison, a VC of 5 μm using the conventional method,
A chip was prepared with an inner layer of VC of 10 μm and Cr ₇ C ₃ of 5 μm, and an outer layer coated with Al ₂ O ₃ of 2 μm particle size to a thickness of 3 μm. The results of cutting tests under these conditions are also shown in Table 2.

EXAMPLE 3 The inner layer shown in Table 3 was produced to a thickness of 4μ by chemical vapor deposition at 1000°C and a reduced pressure of 50 Torr. Moreover, on top of this inner layer, 0.1 μm particle size and 5 μm thickness
Amorphous amorphous Al ₂ O ₃ containing 20% by volume was prepared under the same conditions as in Example 1. These chips were subjected to a cutting test under the cutting conditions shown in Example 1.

[Table] For comparison, the outer layer Al ₂ O ₃ is added to the inner layer in Table 3.
When the product was produced with a thickness of 5 μm (particle size: 2 μm) at 1000° C. and under a reduced pressure of 40 Torr using a conventional chemical vapor deposition method and cut under the same cutting conditions, the cutting time was about half that of the product of the present invention.

Claims (1)

[Scope of Claims] 1 An inner layer consisting of one or more of Ti, V, Cr, Mo, W, and Si carbides, nitrides, carbonitrides, borides, and boronitrides, and 0.01 to 0.5 A coated cemented carbide tool, characterized in that it has a coating layer consisting of an outer layer made of alumina made of amorphous alumina and crystallized alumina with a particle size of μm. 2 Inner layer thickness is 0.5 to 5 μm, outer layer thickness is 0.5
~10μm, the amount of amorphous alumina in the outer layer is 10
A coated cemented carbide tool according to claim 1, wherein the coated cemented carbide tool is 60% by volume. 3 The base material is cemented carbide, and the surface of the base material is coated with Ti,
A layer consisting of one or more of V, Cr, Mo, W, and Si carbides, nitrides, carbonitrides, borides, and boronitrides is coated, and then AlCl ₃ , H ₂ , CO ₂ or A coated cemented carbide tool consisting of further coating with a layer consisting of amorphous alumina and crystallized alumina with a grain size of 0.01-0.5 μm by plasma-enhanced chemical vapor deposition at 500-900° C. in an atmosphere of H ₂ O. manufacturing method.