JPH07164209A - Composite cutting tool - Google Patents

Abstract

PURPOSE:To exhibit excellent cutting performance for a long period, in the case of use of a composite cutting tool in cutting of non-ferrous metal, by forming an artificial diamond thick film on the surface of a particular ceramics sintering basic substance by means of gaseous phase composition. CONSTITUTION:This cutting tool is formed out of either of carbide and carbon nitride of W, TiTa and Mo, or composite carbide and composite carbon nitride of more than two types mentioned above, and is provided with a ceramics sintering basic substance whose theoretical density ratio is 90-96% and thickness is 1-10mm. Artificial diamond thick film whose thickness is 0.1-5mm is formed on the surface of the ceramics sintering basic substance by means of gaseous phase composition. As a result, the thermal expansion coefficient of the basic substance is made roughly equal to that of the diamond thick film, and no peeling-off is generated between them for cutting work under severe conditions. Since the diamond thick film is also very thick, 0.1-5mm, it is possible to exhibit excellent cutting performance for a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, when used for cutting non-ferrous metals such as Al-Si alloys with high silicon content, is a composite composed of artificial diamond thick film that exhibits excellent cutting performance for a long period of time. Regarding cutting tools.

[0002]

2. Description of the Related Art Conventionally, 1 to 1 have been used for the above non-ferrous metal cutting.
0.00 formed on the surface of a WC-based cemented carbide substrate having a thickness of 0 mm and a theoretical density ratio of 98% or more by vapor phase synthesis
A surface-coated WC-based cemented carbide cutting tool coated with an artificial diamond thin film having a thickness of 3 to 0.01 mm is used.

[0003]

On the other hand, recently, there is a strong demand for high performance and labor saving in cutting of non-ferrous metals,
Along with this, heavy cutting such as higher speed cutting, high feed and high depth of cut is unavoidable, but with the conventional surface-coated WC-based cemented carbide tool, under the severe cutting conditions as described above, Due to the large difference in the coefficient of thermal expansion between the diamond thin film and the WC cemented carbide, the diamond thin film easily peels off, and this thin film also contributes to a relatively short service life. It is the current situation.

[0004]

Therefore, the present inventors have
From the above viewpoints, as a result of research to develop a cutting tool that exhibits excellent wear resistance for a long period of time even under severe cutting conditions, the results show that the cutting tool is made of carbides and carbonitrides of W, Ti, and Mo, and these. Of two or more kinds of composite carbides and composite carbonitrides and having a theoretical density ratio of 90 to 96% and a thickness of 1 to 10 mm; .. 1 to 5 mm of the ceramics sintered base and an artificial diamond thick film formed by vapor phase synthesis on the surface of the ceramics sintered base having a thickness of 0.1 to 5 mm. In the tool, since the coefficient of thermal expansion of the substrate and the diamond thick film are almost the same, there is no peeling between the two even in the cutting process under severe conditions. 5mm extreme Thicker and covering waited it was obtained a finding that excellent cutting performance over a considerably long.

The present invention has been achieved based on the above findings, and includes any of carbides and carbonitrides of W, Ti, Ta, and Mo, and two or more kinds of composite carbides and composite carbonitrides thereof. And has a theoretical density of 9
A ceramic sintered base having a thickness of 0 to 96% and a thickness of 1 to 10 mm, and an artificial diamond thick film formed by vapor phase synthesis on the surface of the ceramic sintered base having a thickness of 0.1 to 5 mm. It is characterized by a composite cutting tool constituted by.

The reason why the numerical values are limited as described above in the composite cutting tool of the present invention will be described below. (A) Theoretical density ratio of the sintered substrate The theoretical density ratio of the sintered substrate adjusts the difference from the coefficient of thermal expansion of the diamond film. If the theoretical density ratio exceeds 96%, the coefficient of thermal expansion exceeds And the difference in thermal expansion coefficient from the diamond thick film becomes too large, and the diamond film is liable to peel off. On the other hand, when the theoretical density ratio is less than 90%, the thermal expansion coefficient becomes small and the diamond thick film Therefore, the theoretical density ratio was determined to be 90 to 96% because the difference between the coefficient of thermal expansion and the coefficient of thermal expansion becomes large and sufficient strength cannot be obtained in the sintered substrate.

(B) Thickness of Sintered Substrate If the thickness is less than 1 mm, the desired strength cannot be obtained. On the other hand, if the thickness is 10 mm, the strength is sufficient. It was set to 10 mm.

(C) Thickness of diamond thick film If the thickness is less than 0.1 mm, the desired cutting life cannot be obtained. On the other hand, if the thickness is 5 mm, the desired long-term cutting life can be obtained. The thickness was set to 0.1-5 mm.

[0009]

EXAMPLES Next, the composite cutting tool of the present invention will be specifically described by way of examples. As raw material powder, TiC powder, WC powder, TaC powder, (TiMo) C powder, (TiTa) C having a predetermined average particle size within the range of 1 to 3 μm
Powder, (TiW) C powder, TaCN powder (TiW) CN
Powder TaCN powder (TiTa) CN powder is prepared, and these raw material powders have a length of 30 mm, a width of 20 mm, and a thickness of 20 mm.
Compression-molded to the size of 1600 to 17 in Ar atmosphere
After sintering at 00 ° C. for 3 hours, the temperature of each of the sintered bodies was 15
Various ceramics sintered materials are produced by hydrostatic pressing under the conditions of 00 to 1600 ° C, pressure: 1000 to 1500 atm, and time: 1 hour.
It was processed into a square shape with a thickness of 12 mm, one side of which was polished and then scratched with diamond powder.
Ceramic sintered substrates A to O having theoretical density ratios and thicknesses shown in the table were manufactured, respectively. Then, using the hot filament method, the microwave plasma method and the DC arc plasma method as the gas phase synthesis method on the surfaces of the ceramics sintered substrates A to O, the following conditions are provided: (a) Hot filament method Raw material gas flow rate H ₂ : 500SCCM C ₂ H ₅ OH: 13SCCM Pressure: 30 Torr Filament temperature: 2250 ° C. (b) Microwave plasma method Raw material gas flow rate H ₂ : 300 SCCM CH ₄ : 2.5 SCCM Pressure: 50 Torr Microwave power: 800 W (13.50 MH)
z) (c) DC arc plasma method material gas flow rate _{Ar: 65SLM H 2: 4SLM CH} 4: 0.10SLM Pressure: 80 Torr introduced Power: by forming the film thickness of the diamond thick film shown in Table 2 at 10KVA, The composite cutting tools 1 to 15 of the present invention were produced. For the purpose of comparison, the substrate has a composition of Co: 5.5 wt% WC: balance, and has a theoretical density ratio of 99.9% and a 4.8 mm thick WC-based cemented carbide, And, on this surface, by the hot filament method under the above conditions, the thickness: 0.008
A commercially available surface-coated WC-based cemented carbide cutting tool (hereinafter referred to as a conventional cutting tool) was manufactured by forming an artificial diamond thin film of mm.

Then, with respect to the cutting tools 1 to 15 of the present invention and the conventional cutting tool, Ni metal is vapor-deposited on the substrate side by a sputtering method, and then the vapor-deposited metal side is decompressed in a H 2 atmosphere with a commercially available Ti-containing brazing material. 1000 in
After brazing to a cemented carbide shank at 10 ° C for 10 minutes, with the rake surface polished with a # 2000 diamond grindstone, work material: A390-T6 (Al-18% Si alloy) Cutting speed: 900 m / min Depth of cut 1.2 mm Feed 0.3 mm / rev Cutting time 20 minutes Wet high speed continuous cutting test of Al-Si alloy under the condition of coolant and water-soluble oil, and measured the flank wear width of the cutting edge. The results are shown in Table 2.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

From the results shown in Table 2, all of the cutting tools 1 to 15 of the present invention do not cause peeling in the diamond thick film even at high speed cutting of high Si content Al alloy which is a difficult-to-cut material. While it exhibits excellent wear resistance, it is clear that the conventional cutting tool causes delamination of the diamond film within a relatively short time after the start of cutting, leading to the end of its service life. As described above, the composite cutting tool of the present invention has extremely excellent adhesion to the ceramics sintered substrate of the diamond thick film.
Not only high-speed cutting but also heavy cutting under harsh conditions does not cause peeling of the diamond thick film and exhibits excellent cutting performance for a remarkably long time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical indication C04B 35/56 301 F C23C 16/26 C30B 25/02 P 29/04 X 8216-4G C04B 35 / 56 S

Claims (1)

[Claims] 1. A carbide and carbonitride of W, Ti, Ta and Mo, or a composite carbide or composite carbonitride of two or more of these, and having a theoretical density ratio of 9
A ceramics sintered base having a thickness of 0 to 96% and a thickness of 1 to 10 mm, and an artificial diamond thick film formed on the surface of the ceramics sintered base having a thickness of 0.1 to 5 mm by vapor phase synthesis. A composite cutting tool characterized by being configured with.