Product Code: PIC2008_P142

Microstructural Characterization of Nd:Yag Laser-Welded 12Vol.% Sic Particulate-Reinforced Magnesium Alloy Composite
Authors:
A.H. Wang, Huazhong University of Science and Technology; Wuhan Peoples Republic of China
Z.D. Zhao, No. 59 Research Institute of Ordanance Industry ; Chongqing Peoples Republic of China
H.G. Xu, Huazhong University of Science and Technology ; Wuhan Peoples Republic of China
B. Ye, Huazhong University of Science and Technology ; Wuhan Peoples Republic of China
X.F. Zhang, Huazhong University of Science and Technology; Wuhan Peoples Republic of China
X.P. Dong, Huazhong University of Science and Technology ; Wuhan Peoples Republic of China
C.S. Xie, Huazhong University of Science and Technology ; W Peoples Republic of China
Presented at PICALO 2008

A renovated shielding gas apparatus was successfully used to protect the laser-welded pool during Nd:YAG laser welding process of a particulate SiC-reinforced magnesium alloy composite. Laser welding was carried out by preplacing a thin nano-Ni-powder onto the seam surface. Laser welding parameters, such as beam diameter and scanning velocity, were optimized to obtain sound welded seam. The microstructure and elemental distribution of the laser-welded seam were analyzed by employing scanning electron microscope incorporating energy dispersive X-ray and X-ray diffraction analysis. Results show that, defects-free seams with uniform distribution of SiC particulate and uniform elemental distribution have been generated, and the microstructure of the magnesium alloy matrix in the laser-welded seam was characterized by fine dendrite solid solution without precipitation of magnesium-type intermetallic compound compared to the original composite. The formation mechanism of the seam has been discussed and revealed.