JPH04322903A - Cutting tool excellent in hard phase adhesion, made of ultra-high pressure sintered material - Google Patents

Abstract

PURPOSE:To enhance the wear resistance of a cutting tool made of an ultra-high pressure sintered material composed of a diamond hard phase, c-BN hard phase and a Ti compound group binding phase. CONSTITUTION:A cutting tool is made of an ultra-high pressure sintered material composed of 10 to 60vol.% of a Ti compound group binding phase consisting of more than one kind materials among TiC, TiN and TiCN, as a main component, with inevitable impurities, and 10 to 60% of a diamond hard phase covered with a vapor-deposited c-BN layer having a thickness of 0.01 to 5mum and 10 to 60% of a C-BN hard phase.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention has excellent adhesion of the hard phase to the binder phase, not only for continuous cutting but also for interrupted cutting of composite materials. This invention relates to a cutting tool made of ultra-high pressure sintered material that exhibits extremely little wear and exhibits excellent cutting performance over a long period of time.

0002

[Prior Art] Conventionally, as described in Japanese Patent Publication No. 62-19394, capacity % (hereinafter, % is capacity %) is used.
), mainly consisting of one or more of Ti carbides, nitrides, and carbonitrides (hereinafter referred to as TiC, TiN, and TiCN), and further contains titanium boride and tungsten carbide as necessary. , tungsten boride, aluminum nitride, and aluminum oxide (hereinafter referred to as
TiB2, WC, WB, AlN and Al2 respectively
Ti containing one or more of the following:
Compound binder phase and unavoidable impurities: 10-60%, cubic boron nitride (hereinafter referred to as c-BN) hard phase: 10
A cutting tool made of ultra-high pressure sintered material having a composition of ~60% and a diamond hard phase of 10-60% is known, and this cutting tool made of ultra-high pressure sintered material can be It is also known to be used for cutting.

0003

[Problems to be Solved by the Invention] On the other hand, cutting processes have become more diverse in recent years, and for example, engine blocks in which multiple cast iron liners are cast with Al-Si alloy have been developed for the purpose of reducing the weight of automobile engines. Intermittent cutting of the composite material is indispensable for the production of these materials, but when using the conventional ultra-high pressure sintered material cutting tools mentioned above, the adhesion of the hard phase to the Ti compound binder phase is poor. The current situation is that the hard phase is likely to peel off, resulting in accelerated wear and the end of the service life in a relatively short period of time.

0004

[Means for solving the problem] Therefore, the present inventors
From the above-mentioned point of view, we conducted research to develop cutting tools made of ultra-high pressure sintered materials that exhibit excellent wear resistance even when used for interrupted cutting of various composite materials, and as a result, (a) In general, we found that: Although the Ti compound binder phase has a high bonding strength with the c-BN hard phase, it has a low bonding strength with the hard phase of single diamond. Therefore, when it is used for interrupted cutting of various composite materials, Insufficient wear resistance due to shedding of the hard phase. (b) However, when manufacturing a cutting tool made of an ultra-high pressure sintered material in which the c-BN hard phase and the diamond hard phase coexist, a c-BN vapor deposited layer is formed on the surface of the diamond powder using a normal physical vapor deposition method. When diamond powder coated with c-BN vapor-deposited coating layer is used as raw material powder, c-
Not only the BN hard phase but also the diamond hard phase is c-B.
It firmly adheres to the Ti compound binder phase through the N vapor-deposited coating layer, and therefore, even when used for interrupted cutting of composite materials under severe cutting conditions, the hard phase peels off from the Ti compound binder phase significantly. As a result, the research results show that the wear resistance is suppressed, resulting in excellent wear resistance and a longer service life.

[0005] This invention was made based on the above research results, and it is based on the above research results.
Ti compound binder phase mainly composed of one or more types of N and unavoidable impurities: 10 to 60%, average layer thickness: 0.01
Diamond hard phase coated with ~5 μm c-BN vapor deposited layer: 10-60%, c-BN hard layer: 10-60%,
This cutting tool is characterized by being made of an ultra-high pressure sintered material having a composition of:

Next, the reason why the composition of the ultra-high pressure sintered material constituting the cutting tool of the present invention is limited as described above will be explained.

(a) Ti compound-based bonded phase whose ratio is 10
If the content is less than 60%, the sinterability will decrease and the desired strength cannot be secured, while if the content exceeds 60%, the wear resistance will be significantly reduced.
It was set at ~60%.

(b) Average layer thickness of c-BN vapor deposited layer When the average layer thickness is less than 0.01 μm, Ti of the diamond hard phase
Adhesion to the compound-based binder phase is insufficient, while 5μ
If the average layer thickness exceeds m, it must be deposited thicker on the surface of the diamond powder, which is the raw material powder, in the manufacturing process, which increases the cost. It was determined to be 5 μm.

(c) Diamond hard phase coated with c-BN vapor deposited layer If the proportion of the diamond hard phase, including the c-BN vapor deposited layer, is less than 10%, the desired high hardness cannot be achieved. On the other hand, if the proportion exceeds 60%, the proportion of the Ti compound binder phase and the c-BN hard phase becomes relatively low, and the strength and high temperature hardness decrease. The combined ratio of the coating layer and the diamond hard phase was determined to be 10 to 60%.

(d) c-BN hard phase If the proportion is less than 10%, the high temperature hardness will not be stable, while if the proportion exceeds 60%, the strength and hardness will similarly decrease. Therefore, the ratio was set at 10% to 60%.

[0011] Furthermore, the cutting tool made of the ultra-high pressure sintered material of the present invention starts with raw material powder, preferably 0.1 to 10
On the surface of diamond powder with an average particle size of 0 μm,
For example, the target is hexagonal boron nitride (h-
BN) (in this case, h-BN in the target changes to c-BN during the deposition process, but some h-BN phase or amorphous BN phase may remain). Using the physical vapor deposition method, the c-BN vapor deposited coating layer was
．． This c-BN was formed by vapor deposition with an average layer thickness of 01 to 5 μm.
A predetermined proportion of c- is added to the diamond powder for forming the vapor deposited coating layer.
BN powder, TiC powder, TiN powder, and TiCN
one or more of the powders, and optionally TiB2
powder, WC powder, WB powder, AlN powder, and Al2
Blend and mix one or more types of O3 powder,
All of the following are press-molded into a green compact of a predetermined shape under normal conditions, and the green compact is pressed at a pressure of 5 GPa or more and a temperature of:
Manufactured by ultra-high pressure sintering at 1300°C or higher.

0012

[Example] Next, the cutting tool made of ultra-high pressure sintered material of the present invention will be explained in detail with reference to an example.

[0013] Diamond powders having various average particle sizes shown in Table 1 are prepared as hard phase forming components, and the average layer thickness c shown in Table 1 is applied to the surface of these diamond powders by a normal sputtering method. - A BN vapor-deposited coating layer is formed, and then c-BN powder having an average particle size shown in Table 1 as a hard phase forming component and 0.3 c-BN powder as a binder phase forming component are added to the c-BN coated diamond powder. ~2
TiC powder with a predetermined average particle size in the range of μm, T
iN powder and TiCN powder, as well as TiB2 powder,
WC powder, W2 B powder, AlN powder, and Al2
O3 powder was mixed in the proportions shown in Table 1, wet mixed using acetone as a solvent, and dried.
It is press-molded into a green compact at a pressure of 0 MPa, and the green compact is placed on a support chip having a composition of WC-6 wt% Co and dimensions of diameter: 7 mm x thickness: 2 mm to form a normal belt. The mold was charged into an ultra-high pressure sintering device, pressure: 6 GPa,
Diameter: 7 mm x Thickness: 1 mm (WC-based cemented carbide) is sintered under ultra-high pressure at a temperature of 1,350°C and has substantially the same composition as the compounded composition, and is lined with WC-based cemented carbide. The shape of SPGN432 was obtained by cutting this sintered body into four equal parts, brazing it to a WC-based cemented carbide base of WC-6 wt% Co, and polishing it. Cutting tools 1 to 5 made of the ultra-high pressure sintered material of the present invention (hereinafter referred to as the cutting tool of the present invention) having the following properties were manufactured, respectively.

For the purpose of comparison, a c-BN coating layer was not formed on the surface of the diamond powder, but instead a diamond powder having the same particle size as the c-BN vapor deposition coated diamond powder was used. and the sintering temperature was 150
Cutting tools 1 to 5 made of conventional ultra-high pressure sintered material (hereinafter referred to as conventional cutting tools) were manufactured under the same conditions except that the temperature was 0°C.

[0015] Next, for the various cutting tools obtained as a result, work material: four rod cast iron liners with dimensions of 65 mm in diameter x 15 mm in thickness x 130 mm in height were cast and arranged in parallel. 140mm x length 375mm
Composite material block material with dimensions of x height 130 mm and composition of Al-8 wt% Si, cutting speed: 400
m/min, feed: 0.2mm/rev. , depth of cut:
A wet interrupted cutting (single-blade milling cutting) test was conducted on the composite material under the following conditions: 0.5 mm, cutting time: 100 passes on the upper surface in the length direction of the block material (liner exposed surface), and the flank wear width of the cutting edge was determined. It was measured. The results are also shown in Table 1.

[0016]

[Table 1]

[0017]

Effects of the Invention From the results shown in Table 1, it can be seen that the adhesion of the diamond hard phase in the ultra-high pressure sintered material constituting the cutting tools 1 to 5 of the present invention is improved by the presence of the c-BN vapor deposited coating layer. Since it is of excellent quality, c-
It is clear that these cutting tools exhibit much better wear resistance than conventional cutting tools 1 to 5 in which no BN vapor-deposited coating layer is present.

As mentioned above, the cutting tool made of the ultra-high pressure sintered material of the present invention has a high adhesion of the diamond hard phase in the ultra-high pressure sintered material constituting it, so it can be used not only for continuous cutting but also for continuous cutting. Even in interrupted cutting of composite materials, which requires cutting under even harsher conditions, chipping of the diamond hard phase is significantly suppressed, and as a result, it exhibits excellent wear resistance and can be cut for a long time. It has industrially useful properties such as.

Claims (1)

[Claims] 1. Ti compound binder phase mainly consisting of one or more of Ti carbides, nitrides, and carbonitrides and inevitable impurities: 10 to 60% by volume, average layer thickness: 0. Constructed of an ultra-high pressure sintered material having a composition of: 10-60% diamond hard phase coated with a cubic boron nitride vapor deposited layer of 0.01-5 μm, and 10-60% cubic boron nitride hard layer. A cutting tool made of ultra-high pressure sintered material with excellent hard phase adhesion.