Studies On The Influences Of Vacuum Degree On Cu-Fe Explosive Welding

Vacuum explosive welding is a research technology developed based on atmospheric explosive welding.Compared with the normal pressure conditions,the material obtained by vacuum explosion welding has the advantages of better performance,less noise and no shock wave harm.However,there are relatively few researches on vacuum explosive welding at present,especially the systematic ones.Therefore,the theoretical and experimental research of vacuum explosive welding is still very important.In order to investigate the influence of vacuum on the quality of explosive and explosive welding,the effect of vacuum environment on the microstructure and detonation speed of explosive was carried out.According to the explosion welding window,the thickness of 2mm copper plate and 6mm steel plate as the base plate,the spacing of 4,6 and 8mm based composite plates are simulated by AUTODYN.In the simulation,the three-dimensional model is established by the coupling method of Euler and Lagrange fluid and solid.The optimal base plate spacing is obtained by analyzing the z-direction velocity,displacement,pressure and yield stress of the composite plate.Under the condition of keeping the optimum spacing unchanged,the vacuum degree of 70,50 and 40kPa was simulated respectively to investigate the effect of vacuum on explosive welding.According to the best simulation results,the experiment of Cu Fe vacuum explosion welding is designed and carried out in this paper.The influence of vacuum on explosive welding is characterized by metallographic observation and mechanical properties test.The results show that the vacuum degree also has a certain influence on the particle size and microstructure.The higher the vacuum degree,the greater the influence of vacuum degree on different crystal structure.The experimental results show that the detonation velocity of emulsion explosive is about 2200m/s at atmospheric pressure,and the explosive detonation speed increases first and then decreases with the increase of vacuum.The optimum spacing of the composite plates is 4mm at 120g explosive.The vacuum degree has an effect on the z-direction velocity,displacement,pressure and yield stress of the composite plate.In a certain vacuum range,the bonding quality of the base composite plate is better with the increase of vacuum degree.The tensile strength of composite plates obtained by explosion welding experiments is 502,590,546 and 519MPa respectively under 101,70,50 and 40kPa,which meet the requirements and are bent 90° times outside.The results show that the interface of composite plate is free of cracky which indicates that the composite plate is well combined.The microstructure of the joint surface is observed by metallography.In a certain range,after increasing the distance between the initiation end of explosive welding,the wave length and amplitude of the interface wave will increase accordingly.The bonding strength of the composite plates under three vacuums is higher than that under 101kpa,and the bonding quality is the best at 70kPa.Figure[28]Table[11]Reference[77]...