Development of Improved Cutting Tool Materials.

摘要

When the normal stresses on the tool face are less than about half the transverse rupture strength of the tool,cratering wear of cemented carbide tools occurs by the thermally activated dissolution of the pure WC grains in the tool. Complex carbide grains are not removed in this manner but come off as discrete particles of the order of magnitude of the grain size. At any given cutting temperature,these complex carbides have only a minor influence on the cratering wear rate. The major beneficial effect of the complex carbides appears to be to reduce the chip-tool contact length. The conclusions with respect to the cratering wear of high speed steel tools are generally similar to those for carbide tools. A critical stress level exists below which adhesive wear does not occur. An atomic jump model of thermally activated wear correlates the experimental data with good accuracy. (Author)