JPH02254144A - Manufacture of coated cutting tool having excellent wear resistance and chipping resistance - Google Patents

Abstract

PURPOSE:To obtain the cutting tool having excellent wear resistance and chipping resistance by coating the surface of a sintered hard alloy or a high-speed steel with a hard compound layer of specified metal and thereafter subjecting it to shot peening treatment. CONSTITUTION:The surface of a cutting tool by a sintered hard alloy contg. hard carbide, nitride and carbon nitride of IVa, Va and VIa metal in a periodic table such as W, Ti, Ta, Hf, Nb and Zr and contg. Ni, Co, etc., as a bonding material at the time of sintering or of a cutting tool by a high-speed steel is coated with a single phase of hard substance such as the carbide, nitride, carbon nitride, oxide, oxygen carbide, oxygen nitride and oxygen carbon nitride of the above W or other metal and alumina, etc., or a double layer constituted of two or more kinds among the above by a PVD method, a CVD method or the like. The surface of the superhard coated layer is subjected to shot peening treatment by iron powder, cast steel powder, WC powder, ceramic powder of 10 to 2000mum grain size at >=30 degrees angle of projection and at 20 to 120m/sec projecting speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a cutting tool that requires wear resistance and chipping resistance.

[Prior Art and Problems to be Solved by the Invention] Conventional coated cemented carbide cutting tools are made of carbides, nitrides and carbonitrides of metals of groups 4a, 5a and 6a of the Periodic Table of the Elements, for example. The carbides, nitrides, carbonitrides, and oxides of the metals of groups 4a, 5a, and 6a are added to the surface of the cemented carbide base material containing one or more of the above metals and one or two of Co and Ni. Manufactured by PVD or CVD coating of a single layer or multiple hard layers consisting of two or more of the following: aluminum oxide, oxycarbide, oxynitride, oxycarbonitride, and aluminum oxide. . However, coated cemented carbide cutting tools manufactured using these conventional manufacturing processes exhibit excellent wear resistance when used for continuous cutting, but when subjected to intermittent loads such as milling or turning of grooved materials. In the case of cutting, it cannot be said that both wear resistance and chipping resistance are necessarily satisfactory.

In addition, the high speed steel tool has the above-mentioned 4a and 5 on the surface of the high speed steel.
m layer consisting of one type of carbide, nitride, carbonitride, oxide, oxycarbide, oxynitride, and oxycarbonitride of group A and 6A metals, or a multilayer hard layer consisting of two or more types. PV
Manufactured by D coating. Coated high-speed steel cutting tools produced by this method exhibit excellent wear resistance, but surface-coated cemented carbide cutting tools are not as popular. This is because even higher wear resistance is often required due to cost considerations. As a countermeasure, cutting methods,
Coating method and base material M! according to cutting conditions! q people are employed with the passive ability to use different types of tools, and no knowledge has yet been proposed to proactively improve the performance of tools by improving manufacturing methods.

Therefore, the inventors of the present invention conducted research to manufacture a layered coated tool with excellent wear resistance and chipping resistance, and found that by applying shot peening to the surface of the coated tool, the wear resistance of the coated tool was improved. It was found that the fracture resistance was significantly improved.

[Means for Solving the Problems] The present invention, based on the knowledge described in -1-, has the following configuration.

1. Cemented carbide containing one or more of the carbides, nitrides, and carbonitrides of 48.5a and Iia metals in the Periodic Table of the Elements, and one or two of Co and Nj. The surface of the base material is made of one of carbides, nitrides, carbonitrides, oxides, oxycarbides, oxynitrides, and oxycarbonitrides of Group 01 metals 4a, 5a, and 6a, and aluminum oxide. Wear resistance characteristics characterized by shot peening the surface of the coated cutting tool after coating when manufacturing a coated cemented carbide cutting tool made of a single layer or a multi-layer hard layer coated with two or more types. , a method for manufacturing coated cemented carbide cutting tools with excellent fracture resistance.

2. The surface of high-speed steel is coated with carbides, nitrides, carbonitrides, oxides, oxycarbides, oxynitrides, and oxycarbonitrides of metals from groups 4a, 5a, and 6a, as well as aluminum oxides. In manufacturing a coated high-speed steel cutting tool which is coated with a multi-layer hard layer or a multi-layer hard layer consisting of two or more types, the surface of the coated cutting tool is shot peened after coating. A method for manufacturing N-subject high-speed steel cutting tools with excellent properties and fracture resistance.

3. Abrasion resistance and chipping resistance as described in item 1 or 2 of ``-L, characterized in that the particle size of the shot is 10 μm to 2000 μm, the projection speed is 20 to 120 m/sec, and the projection angle is 30 degrees or more.'' A method for manufacturing coated cutting tools with excellent properties.

Therefore, the typical cemented carbide targeted by this invention is W
, T4. Ta, ) If, Nb, Zrfj one or more of J oxides, nitrides and carbonitrides, and Co,
Contains one or two types of Ni, and a typical coating is Ti.
, Hf carbide, nitride, carbonitride, oxide, oxycarbide, oxynitride, oxycarbonitride, and aluminum oxide. It consists of the CVD hard trade layer. In addition, typical compositions of high-speed steel include Or, Mo, W, V, as alloying elements.
Contains Go, and typical coatings are single or double layers of Ti, 11f carbides, nitrides, carbonitrides, oxides, oxycarbides, oxynitrides and oxycarbonitrides, and aluminum oxides. Consists of multiple PVD hard layers. In the present invention, after coating the hard layer, this coated portion is subjected to shock I/peening. This improves wear resistance and chipping resistance because the residual tension stress on the coating surface becomes compressive stress, and when the residual stress on the coating surface is compressive, the compressive stress becomes even larger. This may be the cause.

The conditions for shot peening on Tl-LJL are as follows: Material of shot: Cast iron, cast steel, WC, Ceramic Shot particle size: 10 μm to 2000 μm Projection speed:
20 to 120 m/sec Projection angle: preferably 30 degrees or more.

The material of the shot can be selected from cast iron, cast steel, WC, or ceramics depending on the quality and thickness of the coating layer, or it can be limited to those with similar properties such as hardness. Not sure. shot particle size]
The limit value is 10 μm or more in order to obtain the necessary kinetic energy.
Since the diameter of a part of the corner of the -1 core is as small as 0.8+r+n+, it is necessary to set the diameter of the shot to 2000 um or less in order to apply the shot uniformly. The lower limit of the projection speed is 2 to obtain the necessary interlocking energy.
The speed is preferably 0 m/sec or more, and preferably 120 m/min to prevent damage to the T-piece coating. The projection angle is 90 degrees when the projection angle is perpendicular to the material, and if it is less than 30 degrees, the predetermined compressive stress cannot be obtained, so it is necessary to set the projection angle to 30 degrees or more.

[Example] Next, the method of the present invention will be specifically explained with reference to Examples.

Examples Engineered tungsten carbide (WC) 90 wt%, titanium carbide (Tie): 2 wL'4, tantalum carbide (
TaC): 2 wt Lord, Co:6ivl:! An indexable tool was manufactured by sintering a square cemented carbide with a composition of T and having a side of 12.7 mm, and coating it with TiC/TlCN/A120i in this order (: V D).

Cast iron balls with an average grain size of 100 um are thrown into this tool at a speed of 8.
Each side of the tool was shot under the conditions of 0 m/sec and a projection angle of 70 to 90 degrees.

On the other hand, as a comparison tool, a tool was manufactured under the same conditions as Example I except for the shot. A cutting test was conducted on the coated tool of the present invention and a comparative tool obtained as a result. The conditions are as follows.

Rigid material: JIS 545G, 5 grooves with a width of 10 vum were equally spaced on a round bar with a diameter of 60 mm parallel to the rolling direction.

Cutting speed: 150 m/min Feed: 0.35 mm/rev 1 cutting depth: 2, Omm Comparing the tool life based on the number of collisions with the groove, the comparison material was 2.
:The tool broke after 1XIO 2 times and its life was reached. The tool of the present invention was damaged at 1.5XlO' and the tool was facing the other way.

The effect of Shoku] was extremely significant.

Example 2 C: 1.3L Si: 0.25%, Mn: 0.
32%, Cr: 4. ]LMo: 3.5L W
: 10! t, V: 3.5 machines Co: An indexable tool was manufactured by pvoJ & overturning TiN on a high speed steel tool of 10%. Each side of the tool was shot with a cast steel method having an average grain size of 150 μm at a shooting speed of 401 n/sec and a shooting angle of 70 to 90 degrees. The shape of the tool is a parting type with a width of 5+ om, a rake angle of 10°, and a front relief angle of 5°. On the other hand, as a comparison tool, a tool was manufactured under the same conditions as the manual example except for the shot. A cutting test was conducted on the coated tool of the present invention and a comparative tool that did not yield the results.

The conditions are as follows.

Work material: 8I S I 121. , ] 4 Diameter 8
0mm, length 50mm cutting machine = NO lathe Cutting speed 80n+/min Feed 0, 05mm/rev Cutting cycle 2.0sec Cutting-B, 0sec Number of cutting cycles when the wear width of the front flank surface becomes 300 μm The wear resistance of the tool was judged based on the size. The comparison tool was cycled 8 x 103 times and the flank wear width was 3.
The wear width of the tool of the present invention reached 300 μm after 5×10 4 cycles. The effects of shot piping are extremely significant.

[Effects of the Invention] By adding a shot peening process to the coating after PVD or CVD coating, the present invention can significantly improve the wear resistance and chipping resistance of cutting tools, and the industrial effect is extremely high. Is there something remarkable?

Claims (1)

[Scope of Claims] 1. One or more carbides, nitrides, and carbonitrides of metals from groups 4a, 5a, and 6a of the Periodic Table of the Elements;
The carbides, nitrides, carbonitrides, oxides, oxycarbides, oxynitrides and oxidants of the group 4a, 5a and 6a metals are coated on the surface of a cemented carbide base material containing one or two of Co and Ni. When manufacturing a coated cemented carbide cutting tool coated with a single layer or a multi-layer hard layer made of one or more of carbonitride and aluminum oxide, after coating, coating cutting is performed. A method for manufacturing a coated cemented carbide cutting tool with excellent wear resistance and chipping resistance, which comprises shot peening the surface of the tool. 2. One of the carbides, nitrides, carbonitrides, oxides, oxycarbides, oxynitrides, and oxycarbonitrides of metals from groups 4a, 5a, and 6a, and aluminum oxide on the surface of high-speed steel. When producing a coated high-speed steel cutting tool made of a single layer or a multi-layer hard layer made of two or more types, the surface of the coated cutting tool is subjected to shot peening after coating. A method for manufacturing coated high-speed steel cutting tools with excellent wear characteristics and fracture resistance. 3. Abrasion resistance and chipping resistance according to claim 1 or 2, characterized in that the shot particle size is 10 μm to 2000 μm, the projection speed is 20 to 120 m/sec, and the projection angle is 30 degrees or more. A method for manufacturing coated cutting tools with excellent performance.