JPH086155B2 - Surface-modified titanium carbonitride-based cermet member with excellent wear resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has excellent wear resistance, and particularly titanium carbonitride (hereinafter referred to as TiCN) that exhibits excellent performance when used as a cutting tool or an abrasion resistant tool. Shown) for the base cermet member.

[Prior Art] Conventionally, generally, the main constituent of the hard phase forming component is TiCN, and the main constituent of the binder phase forming component is an iron group metal (one or more of Co, Ni, and Fe). TiCN-based cermet members are manufactured by ordinary powder metallurgy, and are used as various cutting tools and wear resistant tools, etc. in the state of the sintered skin surface or the state of being ground by grinding. Well known.

[Problems to be solved by the invention]

However, this conventional TiCN-based cermet member does not show satisfactory results in wear resistance, and on the other hand, for the purpose of extending the service life, chemical vapor deposition or physical vapor deposition is used to form a Although a hard coating layer has also been formed, in this case, because the adhesion of the hard coating layer to the surface of the TiCN-based thermet member is not stable, peeling easily occurs in the hard coating layer easily, Since the wear material is not constant, it is difficult to control the tool life and the cost is increased.

[Means for solving problems]

Therefore, the present inventors, from the above-mentioned viewpoint, as a result of conducting research to improve the wear resistance of the TiCN-based cermet member without forming a hard coating layer, it was produced by a normal powder metallurgy method. For the TiCN-based thermite member, put it in a vacuum container, and in an Ar atmosphere at a pressure of 10 ^-1 to 10 ^-4 Torr,
A negative voltage is applied to the member, a glow discharge is generated, and the surface of the member is etched with Ar ions.
After removing Ar and then leaving it in a vacuum with a pressure of 10 ^-1 to 10 ^-4 Torr or in a glow discharge generated under the same pressure, the surface of the member In addition, as compared with the inside of the member, a modified layer having a relatively large amount of Ti and N components and a small amount of iron group metal is formed, and a TiCN-based cermet member having this surface modified layer is formed. Has been found to exhibit excellent wear resistance in practical use.

This invention was made based on the above findings, in which the main component of the hard phase forming component is TiCN, and the main component of the binder phase forming component is the surface of the TiCN-based cermet member composed of an iron group metal, from the surface. Excellent wear resistance due to the formation of a surface-modified layer having a distribution of components containing a large amount of Ti and N, while containing a small amount of iron group metal, over a depth of 0.1 to 0.45 μm compared to the inside of the member. It is characterized by a surface-modified TiCN-based cermet member.

In the TiCN-based cermet member of the present invention, the depth of the surface-modified layer is limited to 0.1 to 0.45 μm because the desired excellent wear resistance is ensured for a long period of time when the depth is less than 0.1 μm. The depth is 0.45μ
The reason is that if it exceeds m, the fracture resistance will decrease.

〔Example〕

Next, the TiCN-based cermet member of the present invention will be specifically described with reference to Examples.

As a TiCN-based thermite member, 51% TiCN-by weight%
Having a composition consisting of 14% WC-9% TaC- 10% Mo 2 C-6% Ni-10% Co, and prepared slow Au H. class tap of the cutting tool model number SNGN432, the slow Au H. class tap, to the vacuum vessel Put in, first apply a vacuum of 1 x 10 ^-5 torr and then 2
An Ar atmosphere of × 10 ^-2 torr was applied to the chip in this state.
A voltage of 1000 V is applied to generate a glow discharge in the container, the resulting Ar ions etch the chip surface for 60 minutes, then Ar is removed, and the atmosphere is made a vacuum of 1 × 10 ^-1 torr. By leaving it in this vacuum for 60 minutes, a chip 1 of the present invention having a surface modified layer formed over a depth of 0.32 μm from the surface was manufactured.

Instead of leaving the chip of the present invention in vacuum at 1 × 10 ^-1 torr, a voltage of -1000 V is applied to the chip in a N ₂ atmosphere of 1 × 10 ^-2 torr to generate glow discharge. Then, under the same conditions, except that the treatment for standing for 60 minutes was performed during this glow discharge, a chip 2 of the present invention having a surface-modified layer formed over a depth of 0.41 μm from the surface was produced.

Further, for the purpose of comparison, the above throwaway chip was placed in a vacuum vessel, heated to 1250 ° C., and maintained at the elevated temperature for 60 minutes as 100 torr N ₂ atmosphere to maintain the range of the present invention from the surface. A comparative chip having a surface modified layer formed over a depth of 0.72 μm was manufactured.

Further, on the surface of the above-mentioned throwaway chip, 0.5% TiN as a hard coating layer by an ordinary physical vapor deposition method.
A conventional surface-coated chip formed with a layer thickness of 2 μm was prepared.

The depth of the surface modified layer in each of the chips 1 and 2 of the present invention and the comparative chip was measured by Auger electron spectroscopy. Both surface modified layers contained more Ti and N components than the inside of the chip, Co and It had a component distribution with a small amount of Ni component.

Next, regarding these 4 types of chips and the slow-away chip (hereinafter referred to as the conventional chip) that has not been subjected to any of the above treatments, the work material: SNCM439 (hardness: H _B 230), cutting speed: 180 m / min A continuous cutting test of steel was carried out under the following conditions: feed: 0.2 mm / rev, depth of cut: 1 mm, cutting time: 60 mm, number of tests: 5, and the flank wear width of the cutting edge was measured. The results of these measurements are shown in FIG.

〔The invention's effect〕

From the results shown in FIG. 1, the conventional chip has relatively low wear resistance. On the other hand, the conventional surface-coated chip also has excellent wear resistance, but the adhesion of the hard coating layer is unstable. For this reason, there are some chips that cause peeling in the hard coating layer, and there are large variations, and in the comparative chip, the depth of the surface-modified layer is too large, so the fracture resistance of this is reduced, and the conventional surface-coated chip It is clear that the chips 1 and 2 of the present invention both show excellent wear resistance, and the variations are extremely small, while the results show large variations as in the case of.

As described above, the TiCN-based cermet member of the present invention,
By forming a surface-modified layer, excellent wear resistance can be stably exhibited over a long period of time, and the amount of wear is almost constant with little variation, so life management is easy and industrially useful. It has various characteristics.

[Brief description of drawings]

 FIG. 1 shows the cutting test results.

Claims (1)

[Claims] 1. A titanium carbonitride-based cermet member comprising a hard phase forming component mainly composed of titanium carbonitride, and a binder phase forming component mainly composed of an iron group metal.
Over the depth of 0.45 μm, the Ti
And a surface-modified titanium carbonitride-based cermet member having excellent wear resistance, which is formed by forming a surface-modified layer having a large amount of N component and a small amount of iron group metal.