Study On Special Welding Process Of Magnesium/Copper,Magnesium/Aluminum And Aluminum/Aluminum For Heat Dissipation Structure

In the construction materials the density of magnesium alloy and aluminium alloy is small,but the specific strength and stiffness are higher than those of ordinary metals,and the processing process is simple.The red copper has excellent physical properties,high thermal conductivity and conductivity,so that it was used in many areas such as electronic equipment,heat exchange and other industrial areas.Magnesium alloy has good electromagnetic shielding effect,low cost of aluminum alloy,and excellent overall performance of aluminum alloy,but there is no outstanding feature in aluminum alloy performance.To improve the performance of parts,different metals can be combined into a composite structure,This can further strengthen the premise of structural performance and further improve the economic benefits.In order to meet the actual production order,this paper uses ultrasonic transient liquid phase welding technique,friction welding technique,Vacuum electron welding technology.The different welding of magnesium alloy,aluminium alloy and copper was realized.The microstructure and properties of the welding compound were discussed and analysed.The effects of different pressure,temperature and ultrasound times on the welding interface were investigated by introducing the ultrasonic welding AZ31 B magnesium alloy and T2 copper by liquid phase welding.The microstructure and mechanical properties of the weld seam during various ultrasonic periods were examined and the development process of the welding structure was discussed.After ultrasound was used only one second during welding and a metallurgical combination was produced.The sharpness reaches 63.67 MPa when the ultrasound application time is 15.s.The fracture mode belongs to brittle fractures and the fracture path is between the metal compound cumgzn and cu5zn8.Friction tube welding(FSW)of the AZ91 D magnesium alloy and the 5A06 aluminium alloy was performed.The welding compounds under different welding parameters were analysed and the welding compounds under different speed parameters were mainly analysed.Rills and other defects on the surface,no holes and other defects inside.The tensile strength of the welding compound can reach 173 MPa,which is about 75% of the base metal of the AZ91 D magnesium alloy.The vacuum electron beam welding(EBW)of the 5A06 aluminium alloy was used for the reproduction of cracks in typical EBW connections of an air-thermal conductor component.The welding parameters have been tested and the microstructure and mechanical properties of welding seams have been investigated.For welded joints with different rolling directions on both sides of the weld seam,the average cracks in the subsequent CNC treatment and the natural ageing process are:This type of welded joint shape should be avoided as much as possible in the actual application case.For welding joints with different running directions on both sides of the weld seam,the tensile strength is also different.The average tensile strength in the same direction is 200 MPa,and the average tensile strength in different directions is 186MPa.