Characterization of Carbide Tool Wear and the Influence of Titanium Carbide Coatings

Abstract

Typical data are presented for the chemical and physical characterization of commercial carbide cutting tools before and after machining tests on heat treated alloy steel AISI-4340. Particular attention is paid to the morphology of crater wear relating chemical constitution and carbide microstructure to tool/workpiece interactions. Direct observation of chemical impurity transfer is reported and a mechanism proposed for the deleterious liquid phase attack of intergranular cobalt. The influence of TiC coatings on improved cutting performance is discussed; and the characteristics of several different coatings correlated with varied machining results. Characterization techniques employed include optical and scanning electron microscopy, electron microprobe analysis and x-ray emission identification.