激光定向能量沉积增材修复5083铝合金组织与力学性能  

Microstructures and mechanical properties of 5083 aluminum alloy repaired by laser directed energy deposition

作　　者：祝弘滨 华倩 李瑞迪[2,3] 徐荣 林泽恒 牛朋达 袁铁锤 ZHU Hongbin;HUA Qian;LI Ruidi;XU Rong;LIN Zeheng;NIU Pengda;YUAN Tiechui(CRRC Industry Research Institute,Beijing 100160,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Shenzhen Research Institute,Central South University,Shenzhen 518000,China)

机构地区：[1]中车工业研究院,北京100160 [2]中南大学粉末冶金国家重点实验室,长沙410083 [3]中南大学深圳研究院,深圳518000

出　　处：《粉末冶金材料科学与工程》2022年第1期45-55,共11页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51871249)。

摘　　要：以Al-Mg-Sc-Zr合金粉末作为修复原料,采用激光定向能量沉积法对开槽5083铝镁合金进行增材修复,用金相显微镜、扫描电镜、电子背散射衍射、室温拉伸试验及显微硬度测试等手段,研究5083铝合金试样修复前后的微观组织与力学性能,同时对不同修复体积占比的试样力学性能进行对比。结果表明:修复区熔合线附近柱状晶呈树枝状,垂直于熔合线方向向基体呈外延生长。修复区为典型的熔池分布,晶粒尺寸为4-9μm,存在较多孔洞,熔合线和扫描轨道附近析出大量Al_(3)(Sc,Zr)颗粒。5083基体材料与开槽修复件的抗拉强度相差不大,分别为190.80 MPa和197.73 MPa,但修复试样的伸长率显著降低。从基体至修复区的2 mm范围内,硬度均值(HV)从50逐渐提高至100。In this paper, the slotted 5083 aluminum-magnesium alloy was repaired by laser direction energy deposition(DED) method, in which Al-Mg-Sc-Zr alloy powders was used as the repairing material. The microstructure and mechanical properties of 5083 alloy samples before and after repairing were studied by means of metallurgical microscope, scanning electron microscope, electron backscatter diffraction, room temperature tensile test and microhardness measurement, etc. Meanwhile, the mechanical properties of samples with different repairing volumes were compared. The results show that the columnar crystals near the fusion line in the repaired area are dendritic and grow epitaxially to the matrix perpendicular to the fusion line. The repaired zone shows a typical molten pool distribution with grain size of 4-9 μm and abundant pores. A large number of Al_(3)(Sc,Zr) particles are precipitated near the fusion line and scanning orbit. The tensile strengths of the 5083 matrix material and the grooved restorations are not much different,which are 190.80 MPa and 197.73 MPa, respectively, but the elongation of the repaired specimens is greatly reduced. In the range of 2 mm from the matrix to the repaired zone, the average hardness(HV) value increases gradually from 50 to 100.

关 键 词：激光定向能量沉积 AL-MG-SC合金 微观组织 力学性能 5083铝合金 修复 增材制造 

分 类 号：TF124[冶金工程—粉末冶金]