JPS6274508A - Surface-coated cemented carbide cutting tip - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cutting tip made of a cemented carbide with a surface of 1 m in which the variation in the amount of wear between cutting tips of the same type is extremely small.

[Conventional technology]

Conventionally, generally, the surface of tungsten carbide (WC) L4 cemented carbide is coated with 4a, 5a, j and 6a of the periodic table.
hX metal, Δl, carbides, nitrides, and oxides of Si, and a single layer of one kind or a composite solid solution of two or more of these? A surface wave 7a cemented carbide cutting tip coated with a hard layer consisting of 12 layers is known.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional surface-coated cemented carbide cutting inserts
If this is put into practical use, even chips of the same type will have one tube phase H.
At present, there is a large variation in the wear m between the two, and therefore the service life is not constant and varies considerably.

(Means for solving problems) Therefore, the inventors of the present invention, from the above-mentioned viewpoint.

As a result of making small holes in order to stabilize the amount of wear in 1 vil coated cemented carbide cutting tips for each type of surface, the reason for the variation in wear ω in the conventional surface coated cemented carbide cutting tips is that The cause is that the hard layer is directly coated on the as-sintered WCC cemented carbide substrate surface, that is, the rough-sintered surface with a surface roughness of about 3.2S. , we have shown the knowledge that if a hard layer is coated on a smooth surface with a surface roughness of 0.2S or less, the resulting dispersion in wear m in surface-coated cemented carbide cutting tips becomes extremely small. It is.

This invention was made based on the above knowledge, and it is possible to apply 4a and 5
a, and group 6a metals, Δ2゜3i carbides, nitrides,
and oxide, and a single layer or a multilayer of two or more of these two or more types of composite solid solutions.
In a surface-coated cemented carbide cutting tip coated with a hard layer, variations in wear amount are significantly suppressed by making the base surface covered with the hard layer a smooth surface with a surface roughness of 0.23 or less. It is characterized by the fact that it was made possible.

In addition, in the cutting tip of this invention, the surface roughness of the substrate surface coated with the hard layer is determined empirically, and if the surface roughness exceeds 0.23, the amount of wear tends to vary. Therefore, the surface roughness was set to 0.2S or less.

〔Example〕

Next, the cutting tip of the present invention will be specifically explained using examples.

WC-7%C0-2%Ti as WC-based cemented carbide M body
Composition of C-3% TaC (weighted percentage) and ISO
Prepare five indexable tips each having the shape of 5NG432, and use a lapping machine to coat the surfaces of the tips covered with the hard layer, that is, the top and side surfaces, to the surface roughness shown in Table 1. The polished smooth surfaces are then coated with a hard layer of the composition and average layer thickness shown in Table 1 using a conventional chemical vapor deposition method to form a surface coating of the present invention consisting of 5 pieces each. Cemented carbide cutting dips (hereinafter referred to as the coated chips of the present invention) 1 to 7 were manufactured.

For comparison purposes, conventional surface-coated cemented carbide was cut under the same conditions except that the surface coated with the hard '11 layer was a rough sintered surface (surface roughness of 3.23). Chips 1 to 7 (hereinafter referred to as conventional coated chips) were manufactured.

Next, regarding the present invention coated tips 1 to 7 and the conventional coated tips 1 to 7, each of which consists of five pieces, the following results were obtained: Work material: SN0M439 (Hardness: 1-18230).

Cutting speed: 200771/min.

Feed: 0.3#/reV.

Depth of cut = 2M5 Cutting time: 20 minutes.

A continuous steel cutting test was conducted under the following conditions, and the flank wear width of the cutting edge was measured for all samples. Based on these measurement results, the variation width (maximum wear a - minimum wear ff1) was determined. These results are shown in Table 1.

[Effects of the Invention] From the results shown in Table 1, it is clear that the coated chips 1 to 7 of the present invention have significantly smaller variations in wear amount than the conventional m-covered chips 1 to 7.

Above) Does the surface-coated cemented carbide cutting tip of this invention cause wear between the tips? Since the variation in the amount of water is extremely small, if the type is the same, it will almost always show the same usage, and this brings about industrially useful effects such as ease of management.

Claims (1)

[Claims] On the surface of the tungsten carbide-based cemented carbide substrate, carbides of group 4a, 5a, and 6a metals of the periodic table, Al, and Si,
A surface-coated cemented carbide cutting tip coated with a hard layer consisting of a single layer or a multilayer of two or more of nitrides, oxides, and composite solid solutions of two or more of these, A cutting tip made of surface-coated cemented carbide, characterized in that the substrate surface covered with the hard layer is a smooth surface with a surface roughness of 0.2S or less.