Surface covered tool

Abstract

Disclosed is a surface covered tool, such as a cutting tool (1), wherein the surface of a base body (2) is covered with a cover layer (6), the cover layer (6) is composed of a lower layer (8) and an upper layer (9), and the lower layer (8) and the upper layer (9) are both composed of columnar particles (10) extending perpendicularly to the surface of the base body (2). The average crystal width of the columnar particles (10b) constituting the upper layer (9) is smaller than the average crystal width of the columnar particles constituting the lower layer, dispersed particles containing tungsten exist in both the lower layer and the upper layer, and the distribution density of the dispersed particles existing in the upper layer is smaller than the distribution density of the dispersed particles existing in the lower layer. The surface covered tool is provided with the cover layer which improves abrasion resistance and defect resistance.

Description

technical field [0001] The present invention relates to a surface-coated tool formed by forming a coating layer on the surface of a substrate. Background technique [0002] Currently, tools such as wear-resistant tools such as cold forging and warm forging tools such as punches and forging machines (headers), sliding members, and cutting tools require wear resistance, slidability, and chipping resistance. The method used in such tools is to form a variety of coating layers on the surface of hard material substrates such as WC-based superhard alloys, TiCN-based cermets, ceramics, diamonds, or cBN, so as to make wear-resistant Improved damage resistance, sliding properties, and chipping resistance. [0003] As such coating layers, TiCN layers and TiAlN layers are generally widely used, and various improvements have been made for the purpose of higher wear resistance and improvement of chipping resistance. [0004] For example, Patent Document 1 describes a cutting tool in wh...

AI Technical Summary

Problems solved by technology

[0010] However, the coating containing a high-hardness ultrafine particle compound such as the above-mentioned Patent Document 1 has insufficient toughness of the coating, and a coating layer excellent in toughness and fracture resistance is desired.

In addition, Patent Document 1 also describes that making the above-mentioned ultrafine particle compound an amorphous substance with high hardness can suppress the propagation of cracks progressing in the film by virtue of energy dispersion in the film. If it is amorphous, the effect of improving toughness is small, and further improvement in fracture resistance is required

In addition, as can be seen in Patent Document 2, the coating layer composed of vertically elongated crystals also has limitations in improving wear resistance.

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