Microstructures and properties of tungsten inert gas welding joint of super-eutectic ZA alloy

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ÎÄÕÂÒ³Â룺387 - 390

Key words£ºZA alloy; welding joint; microstructure; properties

Abstract: The microstructure of butt-welding joint of supper-eutectic ZA alloy in TIG welding was analyzed through optical microscope and transmission electronic microscope. The results show that the weld seam microstructure is fine and mainly composed of columnar crystals and minor equiaxed crystals, the microstructure in the zone near the weld seam is coarse columnar crystals, and the grain in heatª²affected zone does not grow markedly. The joint microstructure at room temperature is consisted of ¦Â phase (rich Al), ¦Ç-Zn,¦Å phase (CuZn compound), Al₄Cu₉ and other compounds. The hardness of the weld bond area and the tensile strength of the joint are a little higher than that of base materials. The specific elongation of the weld and bond area is a little lower than those of base materials.