JPS63251129A - Coated cutting edge for cutting tool - Google Patents

Abstract

PURPOSE:To extend substantially the lifetime of a cutting edge by forming a coat resisting fracture on the honing part of the cutting edge and a coat resisting abrasion on the cutting face, flank and and the like thereof. CONSTITUTION:One, two or more than two coats of titanium carbide, titanium nitride or titanium carbon nitride are formed on the honing part of a cutting edge for a cutting tool, using a physical deposition method. The cutting face, flank or other faces of the cutting edge are applied with the same coats via a chemical deposition method. Or the lower coat is formed with the chemical deposition method and the upper coat with the physical deposition method. And the total thickness of said coats is made 0.5mu to 20mu. According to the afore-said constitution, the coats of the honing part come to have higher tough ness and higher resistance against a fracture, thereby enabling the prevention of a fracture at the honing part of the cutting edge, such as a cutting edge exposed to a continuous cutting load. Also, the formation of the coats on the cutting face, flank and the like of the cutting edge using the chemical deposition method for ensuring superior adhesion and abrasion resistance, enables the lifetime of of the cutting edge to be substantially extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to improvements in coated cutting blades mainly used for cutting metals, and more specifically to improving the chipping resistance and resistance of the cutting blades. It has been improved to improve wear resistance and extend the life of the cutting edge.

[Prior art]

Conventionally, titanium carbide or It is well known that one or more layers of titanium nitride or titanium carbonitride, etc., formed by chemical vapor deposition or physical vapor deposition are widely used to extend the life of cutting edges.

[Problem that the invention seeks to solve]

However, in the above-mentioned cutting tools in which the coating is formed on the surface of the cutting edge by chemical vapor deposition, the coating has good tightness to the cutting edge surface and has excellent wear resistance. There are problems in defect resistance and chipping resistance, and those in which the coating is formed on the cutting edge by the vlj vapor deposition method, which has high toughness and excellent chipping resistance, have problems in wear resistance.

Therefore, if the Iff or two layers of titanium carbide, titanium nitride, titanium carbonitride, etc. are applied to the cutting edge by physical vapor deposition, or by chemical vapor deposition, the cutting edge will be chip-resistant. Those with excellent wear resistance have problems with wear resistance, and those with excellent wear resistance have problems with fracture resistance.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and during cutting, it forms a chipping-resistant coating on the honed part of the cutting edge that receives a particularly large cutting load (receiving the cutting load). The purpose is to extend the life of the cutting blade by forming a wear-resistant coating on the surface.

[Means for solving problems]

The present invention solves the above-mentioned problems by using the configuration described below.

That is, a coating of titanium carbide, titanium nitride, or titanium carbonitride of iff or 2Je5 or more is formed by physical vapor deposition on the honing part of the cutting edge of a cutting tool made of a hard material, and on the rake face, flank face, or other parts. The coating is formed by chemical vapor deposition, or the lower layer (where it is simply cut out with a hard material cutting blade) is formed by chemical vapor deposition, and the upper layer (
The outer layer portion of the layer is formed by physical vapor deposition, and the total thickness of these layers is 0.5 μm to 20 μm.

[Action of the invention]

With the above-described structure, the present invention has high coating toughness (and excellent chipping resistance) at the honed part, and can be cut under severe cutting conditions such as cutting tools such as milling cutters and end mills, that is, repeated cutting loads. What can be added to the blade,
Furthermore, the above-mentioned damage to the coating on the honed portion of tools such as bits and drills in which a cutting load is continuously applied to the cutting edge can be prevented. The shape of the honing formed on the cutting edge is chamfer honing, round honing, combination honing, or the like.

Note that if the thickness of the layer coated on the cutting edge is less than 0.5 μm, the unique effects of forming the film, that is, the toughness of the cutting edge and the chipping resistance and wear resistance cannot be achieved. If the thickness of the layer exceeds 20 μm, peeling of the layer becomes noticeable during cutting, which is not preferable.

The cutting edge may be made of a hard material such as cemented carbide, cermet, ceramics, or special steel.
The coating is formed on the groove and flank surfaces of the cutting blade by chemical vapor deposition, which has good adhesion and is highly wear resistant. However, due to various conditions such as cutting conditions, Good results can be obtained by forming the above-mentioned coating by physical vapor deposition on top of the chemical vapor deposited coating.

〔Example〕

Tip (model number CNM) made of cemented carbide (P30 equivalent)
G120412GG) was prepared.

A titanium carbide film having a thickness of 3 μm was formed on the surface of this chip by chemical vapor deposition.

Next, 0.0゛5 mv to the intersection of the escaped blood and the rake face.
Chamfer honing of sa x Q, Q 8sum x 20° was performed. Thereafter, a 2 μm thick titanium nitride film was formed on the surface of the chip by physical vapor deposition.

As a result of the above, the chamfer honing part of this chip is formed with a titanium nitride layer with a thickness of 2μ by physical vapor deposition.
The groove and flank surfaces are made of two layers: a titanium carbide layer with a thickness of 3 μm formed by chemical vapor deposition, and a titanium nitride layer with a thickness of 2 μm formed on the top surface by physical vapor deposition.

〔Effect of the invention〕

A coating of titanium carbide, then titanium carbonitride, and then titanium nitride was coated on the surface of sample A according to the present invention described above and a cemented carbide equivalent to P30 which had been subjected to water fall honing for comparison. Comparative Sample B was prepared in which a total layer thickness was 8 μm, and Comparative Sample C was prepared in which a similar coating was formed on the surface of a cemented carbide equivalent to P30 that had been chamfer-honed.

The following tests were conducted to confirm the performance of each of these samples.

Tool model number: CNMG 120412GG, work material: 3
0M445 (four grooves formed in the axial direction on the outer circumference), cutting speed: 120m/fniN, feed: 1 on the cutting edge
After applying 00 shocks, Q, l −rn*/rz
Increase the feed in steps of a and keep doing this until the cutting edge breaks.

As a result of the above, comparative sample B has an average cumulative number of impacts of 137.
The cutting edge was damaged at this time. Comparative sample C suffered damage to the cutting edge after an average cumulative number of impacts of 132, whereas sample A according to the present invention had a problem with the cutting edge after an average cumulative number of impacts of 662. The performance was improved by about 5 times compared to .

Claims (1)

[Claims] (1) Apply titanium carbide, titanium nitride, or titanium carbonitride to the honing part of the cutting edge of a cutting tool made of hard material.
A layer or two or more layers of coating are formed by physical vapor deposition, and the coating is formed on the rake face and flank surface or other parts by chemical vapor deposition, or the lower layer is formed by chemical vapor deposition, and the upper layer is formed by physical vapor deposition. A coated cutting edge for a cutting tool, characterized in that the coated cutting edge is formed by a method, and the total thickness of the layers is 0.5μ to 20μ.