Plasma arc welding of SiCp/Al MMCs based on insitu weldalloying
1.School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.State Key Lab of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001 China; 3.Tianjin Xingang Shipbuilding Heary Industry Limited Company, Tianjin 300456, China
Abstract:To restrain interface reaction in the welding of SiCp/Al metal matrix composites(MMCs), and to form new reinforced composites insitu by complementing burnt metallic elements, two fluxcored wires of Al-Ti-Si and Al-Ti-Mg were filled respectively in plasma arc in-situ weld-alloying of SiCp/Al MMCs in plasma gases of argon and nitrogen. The influences of two fluxcored wires on microstructures and mechanical properties of SiCp/Al MMCs joints were investigated. The results show that the formation of needlelike harmful phases of Al4C3 are effectively inhibited by both of the two flux-cored wire fillers. The fluidity of molten pool is improved, and the stable molten pool is obtained. The mechanical properties of welded joint are effectively enhanced by the compactgrain structure and the new reinforced composites of TiC,TiN,AlN,Ti5Si3,MgAl2O4 and fine grain Al3Ti. The maximum tensile strength of welded joints are 232 MPa and 196 MPa, respectively.