Diamond-cladded hard alloy-made cutting tool improving tool nose strength

Abstract

The invention provides a diamond-cladded hard alloy-made cutting tool improving tool nose strength. Stripping resistance between a diamond film and a tool basal body is improved. The tool nose strength is improved. Tool breaking resistance and wearing resistance are also improved. The diamond-cladded hard alloy-made cutting tool comprises a partially-eliminated metal matrix phase zone having a part eliminated by chemical processing from an interface of the tool basal body made of tungsten carbide-based hard alloys and the diamond film towards the tool basal body inner part as deep as 8 mu m. When the tool is observed from the right angle cross section of a rear tool plane adjacent to the tool nose (a zone located within 100 mu m from the tool nose front), a tungsten carbide crystal boundary beyond combination crystal boundaries between the tungsten carbides inside the partially-eliminated metal matrix phase zone and between the tungsten carbides and other carbides has a metal matrix phase with a thickness ranging from 10 nm to 300 nm and a length over a half of the tungsten carbide crystal boundary length exist. The weight ratio of the chromium existing in the metal matrix phase in the tungsten carbide crystal boundary to cobalt is between 0.21 to 0.4.

Description

technical field [0001] The present invention relates to diamond-coated carbonization that exhibits excellent chipping resistance at the tip of a tool tip by possessing excellent toughness and strength in high-speed cutting of difficult-to-cut materials such as carbon fiber reinforced composite materials (CFRP: Carbon Fiber Reinforced Polymer) Tungsten-based carbide cutting tools. Background technique [0002] In the past, a diamond-coated cemented carbide cutting tool coated with a diamond film in a substrate composed of tungsten carbide-based (WC-based) cemented carbide (hereinafter simply referred to as "cemented carbide") is known, but in In the existing cutting tools made of diamond-coated cemented carbide, since the adhesion between the cemented carbide substrate and the diamond film is insufficient, in order to improve this point, it has been proposed that when the diamond film is formed on the cemented carbide substrate, the There are various options such as film for...

AI Technical Summary

Problems solved by technology

[0009] In recent years, in the technical field of cutting tools, there is a strong demand for labor-saving, energy-saving and further cost reduction. Therefore, there is a trend of increasing the speed of cutting processing. However, the above-mentioned existing diamond-coated alloy cutting When tools (hereinafter simply referred to as "diamond-coated tools") are used for cutting various sharp cutting edges, such as drills that require difficult-to-cut materials such as CFRP, the toughness of the tool matrix made of cemented carbide is not sufficient, so it is easy to Breaking of the blade occurs, and there are cases where the service life is reached prematurely

In addition, high-speed cutting of difficult-to-cut materials such as CFRP requires particularly high tip strength. However, the existing diamond-coated tools have insufficient tip strength and are prone to peeling off of the diamond film. Therefore, they cannot perform well after long-term use. Satisfactory chipping resistance and wear resistance, as a result, most of them reach the service life in a relatively short period of time

[0010] As a result of intensive research on the subject of the above-mentioned diamond-coated tool, the present inventors found that in the diamond-coated tool, in order to improve the adhesion between the diamond film and the tool substrate as described above, the Treatment of cobalt in the outermost metal bond phase, but as a result, the toughness of the blade tip decreases, which becomes the cause of the decrease in the strength of the blade tip

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