激光焊接对SLM成形TA15合金微观组织和力学性能的影响  

The effect of laser welding on the microstructure and mechanical properties of TA15 alloy formed by SLM

作　　者：于淼 王俊哲 王世宏 霍俊美 张熹雯 毕中南[3,4] YU Miao;WANG Junzhe;WANG Shihong;HUO Junmei;ZHANG Xiwen;BI Zhongnan(AECC Shenyang Engine Research Institute,Liaoning Shenyang 110000,China;Changzhou G-Light Additive Manufacturing Co.,Ltd.,Jiangsu Changzhou 213100,China;Central Iron&Steel Research Institute,Beijing 100081,China;Gaona Aero Material Co.,Ltd.,Beijing 100081,China)

机构地区：[1]中国航发沈阳发动机研究所,辽宁沈阳110000 [2]常州钢研极光增材制造有限公司,江苏常州213100 [3]钢铁研究总院有限公司,北京100081 [4]北京钢研高纳科技股份有限公司,北京100081

出　　处：《粉末冶金工业》2024年第6期120-127,共8页Powder Metallurgy Industry

摘　　要：通过选区激光熔化成形工艺制备TA15合金,研究了激光焊接对TA15合金微观组织和力学性能的影响。结果表明:SLM成形TA15合金的显微组织为呈网篮状分布的针状α’-马氏体。经焊接后,焊接接头的组织同样以α’-马氏体为主,但尺寸增大,向片状转变。同时,焊接接头位置形成了一定量的魏氏组织。SLM成形TA15合金经焊接后,一方面由于生成了尺寸较大的α’-马氏体,另一方面形成了对塑韧性不利的魏氏组织,使得焊接接头的室温和500℃拉伸性能相比于母材有所降低,其中室温抗拉强度降幅约4.7%~6.1%,室温屈服强度降幅约8.9%~10.2%,室温伸长率降幅约25.5%,高温抗拉强度降幅约8.4%~13.6%,高温抗拉强度降幅约7.2%~10.3%,高温伸长率降幅约12%。母材的横、纵向拉伸断口均由大量细小、均匀的韧窝组成,呈韧性断裂特征;部分焊接接头处由于在焊接时形成了气孔,断口微观形貌上呈现为形状规则、底部光滑的圆孔。气孔的出现导致塑性有较明显降低较,室温和500℃拉伸时的伸长率最大降幅约41%~44%。TA15 alloy was prepared by laser selective melting forming process,and the effect of laser welding on the microstructure and mechanical properties of TA15 alloy was studied.The results indicate that the microstructure of TA15 alloy formed by SLM is needle shapedα'-martensite distributed in a basket like pattern.After welding,the microstructure of the welded joint is also dominated byα'-martensite,but the size increases and transforms into flakes.At the same time,a certain amount of Widmannstatten structure was formed at the welding joint position.After welding,the SLM formed TA15 alloy exhibits a decrease in room temperature and 500℃tensile properties compared to the base material,due to the formation of large-sizedα'-martensite and unfavorable Widmannstatten structure.The room temperature tensile strength decreases by about 4.7%to 6.1%,the room temperature yield strength decreases by about 8.9%to 10.2%,the room temperature elongation decreases by about 25.5%;the high temperature tensile strength decreases by about 8.4%to 13.6%,the high temperature tensile strength decreases by about 7.2%to 10.3%,and the high temperature elongation decreases by about 12%.The transverse and longitudinal tensile fracture morphology of the base material are composed of numerous small and uniform ductile dimples,exhibiting characteristics of ductile fracture.Due to the formation of pores during welding,some of the welded joints exhibit circular holes with regular shape and smooth bottom on the tensile fracture.The appearance of pores leads to a significant decrease in plasticity,with the maximum reduction in elongation at room temperature and 500℃being about 41%to 44%.

关 键 词：激光选区熔化 激光焊接 TA15 微观组织 拉伸性能 

分 类 号：TG456.7[金属学及工艺—焊接]