Microstructural evolution and hardness of as-cast Be-Al-Sc-Zr alloy processed by laser surface remelting

• 作者: Qingdong XU Yu LUO Xiangdong LIU Lei YANG Shixiong HE Xin WANG Wenyuan WANG Tao SHI Ruiwen LI Pengcheng ZHANG
• 来源期刊: 中国航空学报（英文版）
• 年，卷（期）: 2021,（8）
• 页码范围: 131-142
• 页数: 12页
• 语种: 英文

摘要

As-cast beryllium-aluminum (Be-Al) alloy exhibits a coarse microstructure with pore defects due to a large solidification interval,greatly limiting its mechanical properties.In this research,the relationship between laser surface remelting process and microstructure and hardness of as-cast Be-Al-Sc-Zr alloy was established.The experimental results demonstrated that a pore-free refined microstructure of remelted layer was obtained by controlling the parameter of effective laser energy input.The microstructure of as-cast Be-Al-Sc-Zr alloy consisted of equiaxed grains with Al phase forming a continuous frame wrapping Be phase,which was significantly refined in the remelted zone (from 25 μm to 2 μm).The Vickers hardness in the remelted zone (approximately 210 HV) was approximately 3 times that of as-cast Be-Al-Sc-Zr alloy.Analysis of the Vickers hard-ness and the Be phase size showed a good agreement with a Hall-Petch equation.In addition,trans-mission electron microscopy (TEM),auger electron spectroscopy (AES) and X-ray diffraction(XRD) analysis evidenced that Sc and Zr elements formed a single blocky phase Be13(Scx,Zr1-x),which was also greatly refined from 8 μm to 1.5 μm in the remelted zone.The results obtained in this study indicate that the laser surface remelting allowed refining the microstructure and further strengthening the Vickers hardness of Be-Al-Sc-Zr alloy.