Effect of kerf characteristics on microstructures and properties of laser cutting–welding of AA2219 aluminum alloy

Journal of Materials Research and Technology

Cong Chen¹  Kaiyuan Zheng¹  Yi Zhang¹  Ming Gao² 

[1] Hunan Provincial Key Laboratory of Intelligent Laser Manufacturing, Hunan University, Changsha 410082, PR China;Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, PR China;

关键词: Laser-MIG hybrid welding;    Aluminum alloy;    Kerf;    Microstructure;    Property;   

DOI  :  

来源: DOAJ

【 摘 要 】

The purification of laser keyhole is an important means to remove the oxide layer of laser-MIG hybrid welding of aluminum alloy. Four common auxiliary gases (argon, nitrogen, air and oxygen) were used to prepare kerf with different characteristics, which were defined as argon-weld, nitrogen-weld, air-weld and oxygen-weld. The results show that the remelted layer has little effect on the weld morphology. Microstructures characteristics of Argon-welds and nitrogen-welds were the same as machined welds, while the narrow columnar grain zone and coarsen grains exist in air-welds and oxygen-welds. When the thickness of kerf remelted layer increases, the width of columnar grain zone is reducing and the diameter of equiaxed grain is increasing. The argon-weld is with the best tensile property. When the thickness of remelted layer (d) is less than 70 μm, the tensile strength and elongation of argon-weld can reach 278 MPa and 3.1% respectively, which equivalent to that of machined weld. The tensile property of nitrogen-weld is slightly lower than that of argon-weld because of aluminum nitride impurities. The tensile properties of air-weld and oxygen-weld are low because of a large number of oxide impurities and grain coarsening. Regardless of the types of kerf, when the d is less than 136 μm, the tensile strength reaches more than 250 MPa, which meets the application requirements.

【 授权许可】

Unknown