DBTT and tensile properties of as-sintered tungsten alloys reinforced by yttrium-zirconium oxide

Abstract

Tungsten alloys with 0.5wt%Y2O3 and 0-2.0wt%ZrO2 was prepared by spark plasma sintering (SPS). The grain size of W-0.5wt%Y2O3-0.5wt%ZrO2 (WYZ05) is about 1.95 µm, which is much smaller than that of W-0.5wt%Y2O3 (WY). The tensile tests results at high temperature show that compared with pure W and WY alloys, WYZ05 alloy has higher high temperature hardness and lower ductile-to-brittle transition temperature (DBTT). At 500°C, the tensile strength of WYZ05 alloy is 525.2 MPa, which is 67.53% higher than that of WY. The DBTT of W-0.5wt%Y2O3-(0.5, 1.0, 2.0)wt%ZrO2 material is between 300°C and 400°C. According to the microstructure analysis, it is considered that the reason for improving the mechanical properties of WYZ05 alloy is the fine grain strengthening and Orowan strengthening caused by Y2O3/ZrO2 particles.