激光功率对铝/铜激光熔钎焊接头组织及性能的影响  

Effect of Laser Power on Microstructure and Properties of Al/Cu Laser Welding-Brazing Joints

作　　者：杜道忠 张超[1] 周宇浩 DU Daozhong;ZHANG Chao;ZHOU Yuhao(School of Public Utilities,Jiangsu Urban and Rural Construction College,Changzhou 213003,China;School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China)

机构地区：[1]江苏城乡建设职业学院公用事业学院,常州213003 [2]江苏科技大学材料科学与工程学院,镇江212003

出　　处：《机械工程材料》2024年第5期26-32,共7页Materials For Mechanical Engineering

基　　金：江苏省低碳建材与城乡生态工程研究中心项目(苏发改高技发[2021]1368号);江苏城乡建设职业学院自然科学项目(206/XJZK23002);常州市科技计划资助项目(CJ20230024)。

摘　　要：采用激光熔钎焊方法对5052铝合金和T2紫铜进行对接试验,研究了激光功率(2000,2200,2400,2600,2800 W)对接头显微组织和力学性能的影响。结果表明:不同激光功率下接头铜侧钎焊区组织均以柱状晶为主,随着激光功率的增加,焊缝区树枝晶由细针状转变为雪花状;铜侧钎焊区由界面层和金属间化合物层组成,2000,2600 W激光功率下的界面层主要为AlCu相,金属间化合物层主要为Al_(4)Cu_(9)相,2400 W激光功率下的界面层主要由AlCu相和CuZn相组成,金属间化合物层主要为CuZn_(5)相;焊缝区主要由Al_(4.2)Cu_(3.2) Zn_(0.7)和Al_(0.71)Zn_(0.29)相组成。随着激光功率的增加,金属间化合物层厚度增加。激光功率对铜侧钎焊区的显微硬度影响较大,各接头的最高显微硬度均出现在铜侧钎焊区。随着激光功率的增加,接头最高硬度增加,抗拉强度先增大后减小;当激光功率为2400 W时,接头的抗拉强度最大,达到铝合金母材的92%,此时接头在靠近铝合金母材处断裂,而其他激光功率下制备的接头均在铜侧钎焊区和焊缝区处断裂。The welding test of 5052 aluminum alloy and T2 copper was carried out by laser welding-brazing.The effect of laser power(2000,2200,2400,2600,2800 W)on the microstructure and mechanical properties of the joint was studied.The results show that under different laser powers,the microstructure of the brazing zone on the copper side of the joint was mainly columnar.With the increase of laser power,the dendrites in the weld zone changed from fine acicular shape to snowflake shape.The brazing zone on the copper side was composed of interfacial layer and intermetallic compound layer.The interfacial layer at 2000 W and 2600 W laser powers was mainly composed of AlCu phase,and the intermetallic compound layer was mainly composed of Al_(4)Cu_(9) phase.The interfacial layer at 2400 W laser power was mainly composed of AlCu phase and CuZn phase,and the intermetallic compound layer was mainly composed of CuZn 5 phase.The weld zone was composed of Al_(4.2)Cu_(3.2)Zn_(0.7) and Al_(0.71) Zn_(0.29) phases.The thickness of intermetallic compound layer increased with the increase of laser power.The laser power had a great influence on the microhardness of the brazing zone on the copper side,and the maximum microhardness of each joint appeared in the brazing zone on the copper side.With the increase of laser power,the maximum hardness of the joint increased,and the tensile strength increased first and then decreased.When the laser power was 2400 W,the tensile strength of the joint was the highest,reaching 92%of that of the aluminum alloy base metal.The joint welded at 2400 W laser power fractured near the aluminum alloy base metal,while joints welded at other laser powers fractured at the copper side brazing zone and weld zone.

关 键 词：铝/铜异种金属接头 激光熔钎焊 激光功率 显微组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]