The Research On Ti/Al Dissimilar Metal Electron Beam Melting Brazing Compound Welding And Remelting Process

The industrial area has asked for higher quality requirements on the functional materia with the development of science and technology.But the connection strength between titanium alloy and aluminum alloy is always deficiency for its service in the aerospace area because of the physical and chemical difference between the two elements.In this paper an optimization of the process is put forward for the better joint of titanium alloy and aluminum alloy.Welding brazing is the normal way to connect titanium alloy and aluminum alloy and this process could get the two alloy connected with the joint strength no better than 70%of basic materia.In this paper micro area remelting at the interface is added to the welding brazing process in order to heat the titanium alloy side and melt the intermetallic compound layer.The remelting process resulted in the transformation of microstructure?size and constituent of the intermetallic compound layer.In this paper the joint of titanium alloy and aluminum alloy connection tensile strength could be 165MPa which is 75%of the basic aluminum alloy 5052 tensile strength.The connection strength between TC4 and 6061 aluminum could be 184MPa which is 71%of the basic aluminum alloy 6061 tensile strength.In this paper OM?SEM?EDS and XRD are used to help research the microstructure distribution,elements distribution and the phase composition.Results of the reaserch showed that the morphology of intermetallic compound layer has an obvious transformation happened after the remelting process.From XRD's results the intermetalic compound Ti3Al?Ti2Al?TiA12?Ti5Al11?TiAl and TiAl3 are found.The main change is caused by the intermetallic compound TiAl3's decrease.The stretch fracture morphology of samples with the remelting process showedbetter toughness than the ones without remelting process.The element on the stretch fracture surface of the samples with the remelting process is mainly Al element.Also the calculation of the chemical energy is contained in this paper for the theory analysis and results show the intermetallic compound tends to be the TiAl.Also analysis on the topography of fracture surface indicated the remelting process had a toughing effect on the joint between titanium and aluminum.