JPS6150146B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a surface-coated sintered alloy member for a cutting tool that exhibits excellent cutting performance when cutting steel and cast iron, particularly when cutting under severe conditions such as high-speed cutting and high-feed cutting. Generally, tungsten carbide (hereinafter referred to as WC)
Alternatively, titanium carbide (hereinafter referred to as TiC) is the main component, and iron group metals (Fe, Fe,
one or more of the following (Ni, Co), or one or more of the iron group metals and one of the chromium group metals (Cr, Mo, W) and A
or two or more species, and if necessary, as a hard dispersion-forming component,
On the surface of a substrate made of WC-based cemented carbide sintered alloy or TiC-based sintered cermet containing one or more of carbides, nitrides, and carbonitrides of group 4a, 5a, and 6a metals, Similarly 4a, 5a, and
A coating layer consisting of a single layer or a multilayer of two or more of the group consisting of group 6a metal carbides, nitrides, and oxides, and solid solutions of two or more of these metals is formed by chemical vapor deposition or the like. It is well known that surface-coated sintered alloy members made of these materials are used as cutting tools. However, these conventional surface-coated sintered alloy members for cutting tools show excellent cutting life when the workpiece material is steel, but only short cutting life when the workpiece material is cast iron. , on the contrary, cast iron shows a long cutting life;
Most steel machining shows only a short cutting life, and there is no material that shows a satisfactory cutting life when cutting either steel or cast iron, much less high-speed cutting and high feed of both these materials. At present, there is no material that exhibits satisfactory cutting performance when cutting under severe conditions. Therefore, from the above-mentioned viewpoint, the present inventors developed a cutting tool that can not only be used for cutting both steel and cast iron, but also capable of high-speed cutting and high-feed cutting of both of these work materials. As a result of conducting research to develop the above-mentioned conventional surface-coated sintered alloy members, it was found that 4a, 5a, And instead of a coating layer consisting of carbides, nitrides, and oxides of group 6a metals, and solid solutions of two or more of these, a composite carbonate nitride of Si and A [hereinafter referred to as (Si, A) CON] A surface-coated sintered alloy member formed by forming a coating layer consisting of the above (Si, A) with an average layer thickness of 0.5 to 20 μm
The CON coating layer has high room temperature and high temperature hardness, high toughness, and excellent wear resistance and oxidation resistance.
Furthermore, due to its chemical stability at high temperatures, when used as a cutting tool for cutting steel and cast iron, it has an excellent cutting life when cutting both materials, especially when cutting both materials. They found that it exhibits extremely excellent cutting performance even in high-speed cutting and high-feed cutting of materials. This invention was made based on the above knowledge, but the reason why the average layer thickness of the coating layer is set to 0.5 to 20 μm is that if the average layer thickness is less than 0.5 μm, the desired excellent cutting performance cannot be maintained for a long time. On the other hand, if the average layer thickness exceeds 20 μm, the coating process time becomes longer, which not only causes the crystal grains of the coating layer to become coarser and reduce the toughness. This is because the surface becomes rough and uneven. Next, the surface-coated sintered alloy member of the present invention will be specifically explained using examples. Examples Each of the ingredients had the composition shown in Table 1.
Cutting chips of WC-based cemented carbide sintered alloy and TiC-based sintered cermet are prepared, and the surfaces of these cutting chips are subjected to chemical vapor deposition treatment under the conditions also shown in Table 1 to obtain the compositions shown in Table 1. By forming a covering layer having the formula and average layer thickness,
Surface-coated sintered alloy cutting chips of the present invention (hereinafter referred to as present invention coated cutting chips) 1 to 4 and conventional surface-coated sintered alloy cutting chips 1 and 2 (hereinafter referred to as conventional coated cutting chips) were manufactured, respectively. The coating layers in coated cutting chips 1 to 4 of the present invention all had an amorphous solid phase. Next, regarding the coated cutting chips 1 to 4 of the present invention and the conventional coated cutting chips 1 and 2 obtained as a result, work material: SNCM-8 (Brinell hardness: 270),
Steel high-speed cutting test under the conditions of cutting speed: 180m/min, feed: 0.25mm/rev., depth of cut: 1.5mm, work material
SNCM-8 (Brinell hardness: 270), cutting speed:
120m/min, feed: 0.5mm/rev.,

【table】

[Table] Steel high feed cutting test under conditions of depth of cut: 1.5mm, work material: FC-25 (Brinell hardness: 200), cutting speed: 160m/min, feed: 0.25mm/rev., depth of cut:
Cast iron high-speed cutting test under the condition of 1.5 mm, work material: FC-25 (Brinell hardness: 200), cutting speed:
120m/min, feed: 0.5mm/rev., depth of cut: 1.5mm
A cast iron high-feed cutting test was conducted under the following conditions, and the flank wear depth of the chip cutting edge was measured after 30 minutes of continuous cutting. These results are shown in Table 2. From the results shown in Table 2, the coated cutting chips 1 to 4 of the present invention all have much better cutting performance than the conventional coated cutting chips 1 and 2 in high-speed cutting and high-feed cutting of steel and cast iron. show,
It is clear that cutting can be carried out over an extremely long period of time. As mentioned above, the surface-coated sintered alloy member of the present invention has a coating layer that has high room temperature and high temperature hardness,
It also has high toughness, as well as excellent wear resistance, oxidation resistance, and chemical stability at high temperatures (Si, A).

[Table] Since it is composed of -CON, when used for cutting steel and cast iron, it exhibits a long cutting life in both cases, and is also excellent in high-speed cutting and high-feed cutting of both of these work materials. It has properties that make it useful as a cutting tool, such as excellent cutting performance.

Claims (1)

[Claims] 1. Average layer thickness of a composite carbon nitride of Si and A on the surface of a tungsten carbide-based cemented carbide sintered alloy substrate or a titanium carbide-based sintered cermet substrate: 0.5~
A surface-coated sintered alloy member for cutting tools formed with a 20μm coating layer.