Effect of high-energy milling and sintering temperature on the structure of a hardmetal.

Abstract

This paper evaluated the effect of high-energy milling and sintering temperature on the structural characteristics of WC- 10%Co. These samples were sintered at temperatures of 1350°C, 1400°C and 1450°C. The cooling rate of 100°C/h was used within the temperature range of 1000°C and 800°C to relieve residual stress from the sintering process. The samples were submitted to X-ray diffraction analysis with Rietveld refinement in order to characterize, at the atomic level, the effects of each processing stage on the material structure. The high-energy milling process may have accelerated the dissolution process of a large part of the WC particles during sintering, contributing to the formation of n phases. The characterization techniques were effective to evaluate the effects of high-energy milling, sintering temperature and residual stress on the structural characteristics of the composites investigated and the formation of amounts above 34% by weight of the Co W C and Co W C phases.