Investigation of microstructure evolution and mechanical properties of cold crucible directional solidification Nb-Si alloy

Abstract

In this work, the microstructure and properties of Nb-16Si-24Zr alloy directionally solidified by electromagnetic cold crucible under different process parameters were investigated. As the pulling rate increases, the size of both primary Nbss and eutectic Nbss decreases, resulting in a straighter primary dendrite γ-Nb5Si3 and a fishbone like Nbss/γ-Nb5Si3 coupling structure of secondary eutectic. As the power supply increases, the size of the nascent Nbss and γ-Nb5Si3 increases, and the coupling growth trend of Nbss and Nb5Si3 weakens. As the pulling rate and power supply increase, the toughness shows a trend of first increasing and then decreasing, while the room temperature compressive strength gradually increases.