Re-Measurement of Peritactic Temperature of the Sigma Phase in the Ta-Pd System
Richard M. Waterstrat
The anomalously high peritectic temperature reported for the sigma-phase in the Ta-Pd system together with the liklihood that significant losses of palladium had occured during the measurements has led to a reinvestigation of the peritectic temperature. optical metallography was used to detect liquifaction in homogenous single-phase samples of the sigma phase (Ta3Pd) annealed for short periods of time in small temperature increments. This resulted in a revised peritectic temperature of 2000 + 10 degrees C and a revised Ta-Pd phase diagram.