Microstructural evolutions of molybdenum‑rhenium (47.5 wt.%) alloy under room and high temperature compressions

Abstract

Act as a candidate for heat pipe reactor core, molybdenum‑rhenium (47.5 wt%) alloy possesses excellent mechanical properties at a wide temperature range (from room temperature to recrystallized temperature). Compressions at varied temperatures and strain rates were given to study the microstructural evolutions of Mo-47.5Re alloy. Yield strength is similar in sample compressed at 400 °C with high strain rate (1.67 × 10⁻¹ /s) and the one at room temperature with low strain rate (1.67 × 10⁻³ /s). However, deformation twins are only observed under room temperature and are absent as temperature rises to 400 °C. Thus. Twinning in MoRe alloy is much sensitive to temperature. The microstructure of Mo-47.5Re alloy is quite stable even compression at 1200 °C. Although sub-grains increasing after 1200 °C compressions, no recrystallization was detected. In addition, microstructural evolutions of Mo-47.5Re are outstandingly dependent on strain rates at 400 °C, while are much less obviously at 800 °C and 1200 °C. No phase changes are detected, which verifies good structural stability in Mo-47.5Re.