Effects of Y2O3 additions on mechanically alloyed and sintered W-4 wt.% SIC composites

In this study, the effect of Y2O3 additions on the microstructural and the physical properties of W-SiC composites was investigated. Powder blends of W-4 wt.% SiC. W-4 wt.% SiC-1 wt.% Y2O3 and W-4 wt.% SiC -5 wt.% Y2O3 were mechanically alloyed (MA'd) using a Spex mill for 24 h. MA'd composite powders were sintered under inert Ar and reducing H-2 gas conditions at 1680 degrees C for 1 h. Microstructural and morphological characterizations of composite powders and sintered samples were carried out via SEM and XRD analyses. Furthermore, density measurements and hardness measurements of sintered samples were carried out. A highest Vickers microhardness value of 11.4 GPa was measured for the sintered W-4 wt.% SiC-5 wt.% Y2O3 while W-4 wt.% SIC sample possessed the highest relative density value of 97.7%. (C) 2011 Elsevier Ltd. All rights reserved.