Effect of Addition of Sc, Zr, Er on Microstructure of Al-Mg Ingot to Generate Welding Wire and Micro-hardness of Surfacing Layer

摘要

Al-Mg welding wires applied extensively in aluminum alloy welding field.5183 ingot and 5356 ingot added Sc, Zr and Er were fabricated by DC casting method and extruded into welding wire, furtherly. Surfacing layer on 7A52 aluminum alloy prepared by using automatic surfacing formation system. Optical microscopy (OM) and 1600-5122VD MICROMET 5104 micro-hardness tester utilized to observe microstructure of 5183 and 5356 ingots, to measure micro-hardness of surfacing layer fabricated by using 5183 and 5356 welding wire with Sc, Zr, Er addition, respectively. The results indicated that, owing to addition of rare earth element, re-crystallization of Al-Mg extruded ingot to generate welding wire was restrained markedly; Microstructure was refined obviously when Sc added; And average size of the grains was about 10μm. Micro-hardness of surfacing layer improved after addition of Sc, Zr, Er element in the ingots.