Study on micro-cutting of cemented carbides with SEM direct observation method

摘要

This paper describes that the micro-cutting of cemented carbides using PCD (Poly-Crystalline Diamond) cutting tools are performed with SEM direct observation method. The purpose of this study is to clarify the cutting mechanism of the cemented carbides and the behavior of WC particles at the plastic deformation zone in orthogonal micro-cutting. Summary of results are shown as follows. (1) From the in-situ observation of the micro-cutting, primary WC particles were crushed and/or fine grained in the shearing deformation zone. Some of them were observed to collide directly with a cutting edge of the tool as the micro-cutting was carried on. This appears to be the cause of the severe tool wear in turning of the cemented carbides. (2) The thrust cutting forces tend to increase more rapidly than the principal forces, as the depth of cut and the cutting speed are increased preferably in the orthogonal micro-cutting. (3) The tool wear on the flank face was larger than that on the rake face in the orthogonal micro-cutting.