Grain growth behavior of tungsten heavy alloys based on the master sintering curve concept

Abstract

Time and temperature relationships for grain growth by Ostwald ripening are transformed into the master sintering curve (MSC) form. The resulting MSC equations are used to analyze grain size data obtained from W-Ni-Fe heavy alloys that were quenched from sintering temperatures ranging from 1200 degrees C to 1500 degrees C. Activation energies for grain growth during both solid-state and liquid-phase sintering are calculated and compared to experimental values for diffusion. The MSC equations are further modified to include the effect of the solid volume fraction on the grain growth constant. A sensitivity analysis of material properties and process variables shows that the grain growth rate constant is most affected by changes in the sintering temperature and activation energy.