W-2 wt.%Y2O3 composite: Microstructure and mechanical properties

A W-2Y(2)O(3) composite is produced by powder metallurgy, including the pressing of the mixed elemental powders, their sintering and hot forging. The microstructure of the obtained composite is investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. It appears that the material is composed of W grains having a mean size of 1-2 mu m and Y2O3 particles having a mean size of 300 nm to 1 mu m. The W grains contain a high density of dislocations. The mechanical properties of this material are investigated using nanoindentation and 3-point bend test. Berkovich hardness value is found to be 4.9 GPa at 10 N load, which is similar to that of pure W. 3-Point bend test shows that the composite starts to show ductile behavior approximately at 400 degrees C and the bending stress continuously decreases from 200 degrees C to 1000 degrees C. (C) 2012 Elsevier B.V. All rights reserved.