High compressive strong-ductile tungsten-rhenium alloy via B4C addition

Abstract

Tungsten-rhenium alloys with high-temperature strength and creep resistance are widely used in the cutting-edge scientific and technological sectors. However, W-5Re alloy with Re content of 5 wt% shows brittleness at room temperature, limiting its aviation temperature measurement. This work provides W-5Re-xB4C (x = 0∼2.0 wt%) tungsten-rhenium alloys with high compressive performance by introducing B4C ceramic phase and regulating the B4C content. The alloys are composed of W(Re) solid solution, W2B phase and a few W2C. When increasing B4C addition, the grain size of the W(Re) matrix decreases from about 200 μm to 17 μm in W-5Re-2B4C and the content of intermetallic compounds increase to be about 12% in W-5Re-0.5B4C and 58% in W-5Re-2B4C. The W-5Re-0.5 wt% B4C alloy exhibits a high yield strength of 1.19 GPa and compressive plasticity with a plastic strain of 42.50%, while the W-5Re-0.75B4C alloy has a high yield strength of 1.52 GPa and good compressive plasticity of 22.52%, obviously higher than the reported W-5Re alloys. Fine-grain strengthening from the refinement of W(Re) and second-phase strengthening from intermetallic compounds simultaneously enhance the alloys, while good deformability of W(Re) metallic phase contributes to the room-temperature plasticity. This study provides necessary data accumulation and theoretical support for the application of tungsten-rhenium alloys.

Keywords

• Tungsten alloy
• Metallurgy
• Ceramics
• Microstructure
• Mechanical properties