Dynamic recrystallization behavior of biomedical CCM alloy with additions of C and N

Abstract

In order to examine the dynamic recrystallization (DRX) behaviors of Co-29Cr-6Mo alloy with additions of both C and N (hereafter CCMCN alloy), uniaxial compression tests in the temperature range of 1273 to 1473 K and strain rates of 0.01 to 30s-1 were carried out. The influence of hot forging conditions (i.e., temperature, strain rate, and strain) on the microstructure of deformed sample was investigated in detail by means of electron backscattering diffraction (EBSD) and optical microscopy (OM). The results revealed that the initial microstructure is a stable y face-centered cubic (FCC) phase with a large number Of M23C6 precipitates both inside the grains and at grain boundaries. The DRXed grains were observed to be uniformly distributed and to decrease with strain. The high volume fraction of Ε3 boundaries after the DRX was observed, indicating a close relation between the DRX mechanism and Ε3 boundary formations. In addition, the activation energy Q of CCMCN alloy was observed to be higher as compared to those of alloys without C or N addition and that with N addition. © 2010 The Japan Institute of Metals.