Process,Microstructure and Properties of Titanium-Aluminum Heteroalloy Connected by Laser Melting Deposition
To overcome the difficulty in connecting TC4-7075 heteroalloy with large differences in physical parameters,and to expand the application range of high specific strength titanium-aluminum heteroalloy composite structure,AlTiVNbSi high-entropy alloy was selected as the intermediate layer material,and the effective connection of TC4 and AA7075 heteroalloys was realized by laser melting deposition technology,and the macromorphology,microstructure,component distribution and interface characteristics of the junction area were characterized by OM,SEM,EBSD,microhardness and tensile experiment.The results show that the connection joint is well combined with the TC4 titanium alloy side interface,and there is an interface transition zone with a width of about 20 μm.Weisler tissue is bundled on TC4 near the interface,and a compound area with a width of 20 μm exists at the 7075 side interface.Based on AlTiVNbSi as the intermediate layer material of high-entropy alloy,laser melting deposition technology can realize the effective connection of titanium-aluminum heteroalloy,the hardness(HV)of the joint is about 6822.37 MPa,which is higher than that of the base metal,the hardness of the connecting zone on the near titanium side is higher than that of the connecting zone on the aluminum side,and the tensile strength is 116 MPa.