Microstructure and Fractrue Behaviors of Welded Joint of Particle Reinforced SiCp/ZC71 Magnesium Matrix Composites

Abstract:

The laser welding of particle reinforced SiCp/ZC71 magnesium matrix composite was carried out using a Nd:YAG laser welding experimental system. The mechanical properties of welded joint was studied by tensile test and the morphology of tensile fracture, microstructure as well ingredient of welded joint were observed by SEM. The results show that welding technology for composites is harsher. SiC particles distributed uniformly and the white magnesium intermetallic compound dots disappeared in the laser welded seam because the precipitation of the magnesium intermetallic compounds was prohibited owing to the rapid solidification and cooling of the laser-welded seam.. There is no evident heat affect zone in the weld seams；The mechanical properties of welded joint are worse than those of matrix metal. The weld zone is the weakest part in welded joint. The much lower tensile strength of the seam compared to the tensile strength of the ZC71/SiCp substrate attributed to the surface roughness of the seams and some solidification micron-sized pores (especially between SiC particles and magnesium alloy matrix)，The fracture morphology of welded joint indicated a brittle cleavage fracture.

• Periodical: Materials Science Forum (Volumes 704-705)
• Pages: 706-709
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.704-705.706
• Online since: December 2011
• Authors: Xiao Ming Dong, W.Y. WANG, Jing Pei Xie, Jing Xu, Ai Qin Wang
• Keywords: Laser Welding, Microstructure, SiCp/ZC71 Magnesium Matrix Composite, Tensile Strength

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