Study On Vacuum Diffusion Bonding Of Aluminum With Titanium And Tantalum

Different kinds and different properties of metal,alloy or metal can be connected by welding method,which can give full play to the advantages of their own,so the welding of dissimilar materials applies widely in engineering and production practice and plays an important role in aviation,aerospace and atomic energy and other fields.Compared with the same kind of metal,the welding of dissimilar metals is very difficult,which is caused by the difference of the physical and chemical properties of the metal being welded.Diffusion bonding is an important method to connect dissimilar metals.The consumption of aluminum is just after steel.Titanium and tantalum have high melting point.There are great differences between aluminum titanium and tantalum in melting point,the linear expansion coefficient,thermal conductivity and so on.We need to choose proper welding method and parameters to connect them.This paper mainly studies the vacuum diffusion bonding of aluminum with titanium and tantalum.In this paper,Ti/6061 Al and Ta/6061 Al samples were prepared under different welding temperature and different holding time,and were tested by Inspekt 100 kN universal testing machine and characterized by Hitachi S-3400 N scanning electron microscope.Mechanical property and microstructure were studied to explore the influences of temperature and holding time on the samples,thus best process parameters are determined and preparing technology are optimized.The results of this study indicate that vacuum diffusion bonding process can be used in the connection of titanium with aluminum and tantalum with aluminum.With the increasing temperature,the welded joint connected more closely,and the strength is also increased.However,the joint strength decreased as the temperature reaches a certain value.The fracture mode of the welded joint was of brittle nature,and cleavage step appeared on the fractured surface.The interface of the welded joints were getting smooth as the holding time extended,while the thickness of diffusion layer were about the same.The best parameters for the Ti/6061 Al vacuum diffusion welding process is heating at 450?for 3h,which for Ta/6061 Al vacuum diffusion welding process is 3h at 500 ?.