Effect of Welding Wires Containing ZrB 2 Particles on Microstructure and Mechanical Properties of Spray-Formed 7055 Aluminum Alloy TIG Welded Joints

摘要

In this paper, a series of welding wires with ZrB 2 particles were developed by the in situ reaction, and the ZrB 2 particles were successfully introduced into the spray-formed 7055 aluminum alloy welded joints by TIG welding. The microstructure, hardness, and tensile strength of the welded joints were tested by metallographic microscope, SEM, EDS, Vickers hardness tester, and tensile testing machine. The results show that the microstructure of ZrB 2 /7055 welded joints is fine dendrites. The hardness of the weld zone of the ZrB 2 /7055 welded joint is higher than that of the 7055 welded joint. With the increase of ZrB 2 particles’ content, the tensile strength of welded joints increases first and then decreases. When the content of ZrB 2 particles is 1.5?wt.%, the tensile strength reaches the maximum value of 280?MPa. The tensile strength of the welded joint containing 1.5?wt.% ZrB 2 particles is 14% higher than that of the pure 7055 aluminum alloy welded joint.