JPS59170264A - Surface coated sintered hard alloy member for cutting tool - Google Patents

Abstract

PURPOSE:To improve machineability and life by forming a hard coating layer of aluminum oxycarbonitride of a crystal type on a coating layer formed on the surface of a prescribed sintered hard alloy base body. CONSTITUTION:A titled member is obtd. by forming a hard coating layer of aluminum oxycarbonitride of a crystal type on a single or double coating layers formed on the surface of a sintered hard alloy base body. Said sintered hard alloy base body is mainly formed of a hard dispersion phase formed of >=1 kind among carbide, nitride and carbonitride of IVa, Va and VIa group metals of periodic table and a bond phase formed of >=1 kind among ferrous metals or said metals and >=1 kind of chromium group metals and Al. The single or double coating layers formed on the surface of said base body consist of carbide, nitride and oxide of IVa, Va and VIa group metals of periodic table as well as a solid soln. of >=2 kinds among said materials.

Description

[Detailed Description of the Invention] This invention provides an excellent cutting tool when used for cutting steel and cast iron, especially for heavy cutting such as high-speed cutting of these rigid materials, high-feed cutting, and deep-cut cutting. The present invention relates to a surface-coated cemented carbide member that exhibits cutting performance.

Generally, the hard dispersed phase is mainly 4a of the periodic table of elements,
5a, and one or more of carbides, nitrides, and carbonitrides of group 6a metals, while the dependent phase is mainly composed of one or more of iron group metals, or iron. One or two of the group metals (heavy or higher,
The same (4a+5
A coating layer consisting of a single layer or a multilayer of two or more of the group consisting of carbides, nitrides, and dredged materials of a+ and group 6a metals, and solid solutions of two or more of these is formed by chemical vapor deposition. It is well known that surface-coated cemented carbide members formed by such methods are used as cutting tools.

However, some of these conventional surface-coated super 1" EZ alloy parts show excellent cutting performance when used for cutting steel, but do not show the desired cutting performance when cutting cast iron, and are relatively poor. Others, on the contrary, show excellent performance when cutting cast iron, and exhibit comparatively long service lives, while others show poor performance when cutting steel. It does not exhibit satisfactory cutting performance when cutting both steel and cast iron, such as short cutting life, and even more so when cutting these corrugated materials at high speed, high feed cutting, and deep cutting. Of course, this is true when cutting under severe conditions such as cutting.

Therefore, from the above-mentioned viewpoint, the inventors of the present invention have found that it can be used not only for cutting both steel and cast iron, but also under severe conditions such as high-speed cutting and heavy cutting of both of these corrugated materials. As a result of our research to develop a cutting tool that exhibits excellent cutting performance even when cutting, we found that crystalline aluminum carbonitride oxide (hereinafter referred to as All CN O ), this A7 CN O becomes
It has high hardness and toughness at room and high temperatures.

Since it is chemically extremely stable at high temperatures, the resulting surface-coated cemented carbide member with the A7 CNO layer formed is excellent when used as a cutting tool for cutting steel and cast iron. Furthermore, we have found that even when used for high-speed cutting and heavy-duty cutting of the above-mentioned rigid materials, the same excellent cutting performance can be achieved and a long service life can be ensured. It was.

This invention was made based on the above findings, and the above MCN0 coating layer can be formed in a normal plasma chemical vapor deposition apparatus under high temperature and reduced pressure at a pressure of 0.1 to 10 torr and a temperature of 800 to 1200°C, and in an atmosphere. Inside, Al
Using a mixed reaction gas consisting of C4, CO2, N2, H2, and Ar, a negative voltage or high frequency is applied to the substrate to generate a glow discharge, thereby activating the atmosphere and producing crystalline klcNO' on the surface of the member. It can be formed by vapor deposition. In addition, A, l? obtained as a result? It can be easily confirmed by X-ray diffraction measurement that the CNO coating layer has crystal engraving, and the atomic ratio is Alo, 5a - o, at Co, + 5 - 0.22.
It has a composition of NO, 02-0, 0800, 13-0, 20.

Further, it is desirable that the average layer thickness of the AACNO coating layer of the present invention is 0.5 to 20 μm, because if the average layer thickness is less than 1.5 μm, the desired excellent cutting performance cannot be maintained for a long period of time. On the other hand, 20.
The reason for this is that if the layer thickness exceeds Um, the coating process time becomes longer, which causes the crystals to become coarser and reduce toughness, but also that the surface becomes rough and uneven. EXAMPLES Next, the surface-coated cemented carbide member of the present invention will be specifically explained with reference to Examples.

EXAMPLES Surface-coated cutting chips having the substrate compositions and coating layers shown in Table 1 were prepared as surface-coated superhard alloy members, and these surface-coated cutting chips were subjected to a reaction in a conventional plasma chemical vapor deposition apparatus. The surface of the present invention is then charged into a container, and then subjected to plasma chemical vapor deposition treatment under the conditions shown in Table 1 to form a harder MCNO coating layer on the surface of the surface-coated cutting tip. Coated cutting tips 1 to 9 were each manufactured.

Next, the surface-coated cutting tip 1 of the present invention obtained as a result
The composition, crystal form, Vickers hardness, and average layer thickness of the A7 CN O coating layer in Samples 9 to 9 were measured, and these measurement results are also shown in Table 1.

Furthermore, regarding the above-mentioned surface-coated cutting tips 1 to 9 of the present invention, rigid material: SNCM-8 (hardness: HB270), cutting 1''u
Speed: 180 m/min.

Feed: 0.25 mu/rev, depth of cut: 1.
5mm, cutting time 230m1n.

High-speed cutting test of copper under the conditions and work material: FC-
25 (hardness: HB200), cutting speed: 200 m/
High-speed cutting test of cast iron under the following conditions: min, Feed: 0.25 goose/rev, Depth of cut: 1.5 mm, Cutting time: 20 min, Work material: FC
-25 (hardness: HB200), cutting speed: 140m/
mtn.

Feed: 0.5 yni/rev.

Depth of cut: 11-5n.

Cutting time: 20m1n.

A high feed cutting test was conducted on cast iron under the following conditions, and the flank wear width of the cutting edge after the test was determined to be 4111. The results of these measurements are shown in Table 2. Table 2 also includes, for comparison purposes,
In the above-mentioned surface-coated cutting chips 1 to 4 of the present invention, the surface-coated cutting chips before forming the AlCN O coating layer (hereinafter referred to as conventional surface-coated cutting chips 1 to 4) and the conventional surface-coated cutting chips 1 to 4, respectively. The cutting test results under the same conditions of surface-coated cutting chips f (hereinafter referred to as conventional surface-coated cutting chips 5 to 8) in which 40 g of A with an average/% second table thickness of 2.5 μm was further coated on the surface of No. 4 are also shown. Ta.

From the results shown in Table 2, the surface-coated cutting tips 1 to 9 of the present invention are superior to the conventional surface-coated cutting tips 1 to 8 in both high-speed cutting of steel and cast iron, and high-feed cutting of cast iron. It is clear that it exhibits excellent cutting performance and can be used stably for a long period of time.

As mentioned above, the surface-coated cemented carbide member of the present invention includes:
Due to the formation of the AlCN0 layer, it exhibits high hardness at both room and high temperatures, and is chemically extremely stable at high temperatures.This, combined with the toughness of the cemented carbide base itself, makes it possible to use this as a cutting tool. When used, it exhibits excellent performance in cutting both steel and cast iron, and even in high-speed cutting and heavy cutting of steel and cast iron, which require cutting under even harsher conditions. It provides stable performance over a long period of time.

Claims (1)

[Claims] The hard dispersed phase is mainly 4a and 5a of the periodic table of elements.
+ and 6a group metal carbides, nitrides, and carbonitrides, while the binder phase is mainly composed of one or two iron group metals (S, upper °,
Or one or more iron group metals and one of the chromium group metals and Al! Group 4a, 5a+ and 6a metals of the periodic table (carbides, nitrides, iron oxides etc. , and one of the solid solutions of two or more of these 111le&
or multiple layers of two or more buildings), the entire covering layer "l'!,
A surface-coated super-hard alloy member for a cutting tool, which further comprises a hard coating layer made of crystalline aluminum carbonitrate on the wave layer.