摘要
由激光粉末床熔融(LPBF)成形的纯钼材料普遍存在着致密度低、孔隙缺陷多的问题,对其宏观力学性能具有较大影响。重熔作为LPBF工艺中常见的扫描策略,对提高难熔金属的致密度、改善其力学性能具有重要作用。采用重熔与未重熔工艺分别获得了纯钼试样,研究了两种工艺试样的微观组织与力学性能差异,通过对比致密度、缺陷、微观组织以及维氏硬度与拉伸性能,揭示了重熔工艺对LPBF纯钼成形质量的影响规律及作用机制。结果表明:重熔后缺陷明显减少,致密度得到了显著提高,晶粒增大,平行于成形方向的硬度提高、强度降低、断后伸长率增加,为增材制造金属钼及其合金的性能调控提供了参考。
Pure molybdenum materials fabricated by Laser Powder Bed Fusion(LPBF)generally suffer from low density and porosity defects,which significantly affect their mechanical properties.As a common scanning strategy in the LPBF process,remelting plays an important role in improving the density and mechanical properties of refractory metals.This study investigates the differences in microstructure and mechanical properties between pure molybdenum formed by remelted and non-remelted processes.By comparing density,defects,microstructure,Vickers hardness,and tensile properties,the influence of the remelting process on the formation quality of molybdenum and its mechanism are comprehensively analyzed.The results show that,the defects are significantly reduced and the density is markedly increased after remelted.The grain size and Vickers hardness parallel to the building direction are also increased.Meanwhile,the strength is decreased,but the elongation after fracture is increased.The research results provide a reference for the performance regulation of additively manufactured molybdenum and its alloys.
作者
龙绍军
何勇
段骞
李元峰
黄国亮
黄科
孙超
刘颖
LONG Shaojun;HE Yong;DUAN Qian;LI Yuanfeng;HUANG Guoliang;HUANG Ke;SUN Chao;LIU Ying(Institute of Nuclear Fuel Component and Materials Research,Nuclear Power Institute of China,Chengdu 610213,Sichuan,China;College of Materials Science and Engineering,Sichuan University,Chengdu 610065,Sichuan,China;National Key Laboratory of Nuclear Reactor Technology,Nuclear Power Institute of China,Chengdu 610213,Sichuan,China;Nuclear Power Additive Manufacturing Laboratory,Chengdu 610213,Sichuan,China)
基金
中国核动力研究设计院联合基金(HG2023163,HG2022173)。
关键词
激光粉末床熔融
钼金属
重熔工艺
微观组织
力学性能
laser powder bed fusion
molybdenum metal
remelting process
microstructure
mechanical properties
