Copper And Aluminum Resistance Brazing Process And Process Research

In modern industrial product ion,lightweight manufacturing has become an effect ive way to achieve energy saving and environmental protect ion.For the connect ion of copper-aluminum transit io n clamps of specific shapes in high-speed rail lines,a replaceable compound designed specifically for large-end resistance welding is designed.Electrode,this paper uses resistance brazing method to connect the copper and aluminum materials,based on Lab VIEW temperature data acquisit ion system to collect the temperature signal of different brazing materials in the wett ing process during the welding process,and analyze the solder jo int under different process parameters Temperature provides a basis for the formulat ion of process parameters.In this paper,resistance braz ing technology is used to realize the resistance brazing lap experiment of 1060 aluminum allo y and T2 copper allo y through the select ion of Sn-based solder and Zn-based solder.The systematic research work mainly includes the use of Zn-based solder copper / Research on the welding technology of aluminum dissimilar metals resistance brazing and post-weld heat treat ment of butt jo ints.By comparing the jo int mechanical propert ies of two kinds of commo nly used solders,Zn-based solder is selected finally.The shear strength of the jo ints under different welding process parameters(welding current,welding t ime,welding pressure)is analyzed according to the fractur e microstructure organizat ion.The main research results show that: when Zn Al solder is used in co mbinat ion with potassium fluoroaluminate flux,the opt imal process parameters of the jo int: the welding current is 5500 A,the welding t ime is 12 s,and the electrode pressure is 2355 N,the jo int has the highest shear resistance,4.35 k N.The fracture mode o f the jo int is a mixed fracture of plast ic fracture + britt le fracture.Secondly,in the study of post-weld heat treat ment process,the effects of heat treat ment temperature and holding t ime on the thickness of intermetallic compounds and the shear strengt h of jo ints were studied.Studies have shown that after post-weld heat treat ment,the thickness of intermetallic compounds increases wit h the increase of heat treatment temperature and the holding t ime.The shear strength of jo ints increases first and then decreases,but the overall The mechanical propert ies of the heat-treated jo ints are improved.A data acquisit ion system based on Lab VIEW is designed.By collect ing the temperature of the welding process: the temperature and electrical signals during the spreading phase of different solders during the wetting process,the changes of the solder temperature and dynamic resistance at each spreading stage are analyzed.The dynamic resistance curve drawn according to the temperature and electrical signals acquired and detected can divide the resistance brazing into two stages: the solder wett ing stage and the spreading stage.In different stages,the solder spreading and wett ing process spreading temperature The curve shows different dynamic resistance characterist ics.Wit h the change of welding current and welding t ime,the soldering temperature provided by the resistance welding machine is different.The process o f solder wett ing and spreading will produce different changes with the temperature,forming different solder welding temperature and jo int qualit y change characterist ics,and these temperature change characterist ics can be fully reflected in the dynamic resistance curve.