Study On Interface Characteristics And Numerical Computation Of Explosive Welding Of Heterogeneous Metals

As a special solid-state welding technology,explosive welding has been widely used in the production of various metal and non-metal composite materials.Explosive welding uses the huge energy generated by explosive detonation to drive the collision between materials,making the collision zone produce plastic flow and melting,and realize the welding under the action of high temperature,high pressure and mutual diffusion.Explosive welding is a technology intergrating fusion welding,pressure welding and diffusion welding.Al/Cu composite materials are widely used in electrode materials,electronic technology and other fields due to their excellent conductivity and thermal conductivity.In this paper,the Al/Cu composites were fabricated by traditional explosive welding technology.At present,there are many studies on the welding of common metals at home and abroad.However,there are few studies on the welding of new alloy materials.As a new alloy material,amorphous alloy has many excellent properties compared with traditional metals,such as high strength,high hardness,corrosion resistance,high temperature resistance and so on,which are widely used in military defense,aerospace,atomic energy and other fields.Due to the low ductility of bulk metallic glass?BMG?and the tendency to crystallize at high temperature,the traditional welding technology cannot effectively weld them with common metals.In this paper,the Al and Zr-BMG were innovatively welded using underwater explosive welding technology.Through the combination of theoretical analysis,experimental research and numerical computation,the Al/Cu and Al/Zr-BMG composites were systematically studied.The main conclusions of this paper are as follows:1.The Al/Cu composite plate was manufactured by explosive welding technology.The joining interface of the composite plate after welding was characterized by optical microscope?OM?,scanning electron microscope?SEM?and micro-hardness tester.In order to verify the weldability of Al and Cu,the Al/Cu explosive weldability window was calculated.The results show that the explosive welding technology has successfully realized the preparation of Al/Cu composites.The Al/Cu joining interface presents regular waveform structure characteristics without visibles cracks or defects.The diffusion of elements occurred in the interface vortex zone,accompanied by the formation of intermetallic compounds.The micro-hardness near the joining interface increased,while that far away from the joining interface decreased.The parameters used in the experiment are located in the Al/Cu explosive weldability window,and the experimental results are in consistent with the theoretical calculation results.2.The Zr₆₀Ti₁₇Cu₁₂Ni₁₁ bulk metallic glass?Zr-BMG?and Aluminum 1060 plates were prepared by the underwater explosive welding using varied-thickness ammonium fuel oil?ANFO?explosive.The joining interface of the composite plate after welding was characterized by optical microscope?OM?,scanning electron microscope?SEM?,high-resolution transmission electron microscopy?HRTEM?and micro-hardness tester.In order to verify the weldability of Al and Zr-BMG,the Al/Zr-BMG underwater weldability window was calculated,and the influence of different thickness explosives on the joining interface was analyzed according to the kinetic energy loss theory.The results show that the Al/Zr-BMG composites were successfully manufactured by underwater explosive welding technology.There are no obvious defects in the welded interface,and a transition layer was formed in the bonding interface.The Zr-BMG has not been crystallized after welding,and the hardness increased near the joining interface.3.In order to reveal the explosive welding mechanism and verify the weldaility of Al/Cu and Al/Zr-BMG composites,the explosive welding processes of Al/Cu and Al/Zr-BMG were simulated by smooth particle hydrodynamics?SPH?method.The results show that the Al/Cu joining interface has obvious metal jet,and the interface presents regular wavy structure characteristics,the simulated interface vortex structure is very similar to the experimental vortex structurte.The numerical simulation results are in consistent with the experimental results.The Al/Zr-BMG joining interface presents an almost flat structure and the bonding quality is good,which is in consistent with the experiemental results.Meanwhile,the Johnson-Holmquist-Ceramics?JH-2?constitutive model was selected as the constitutive model of Zr-BMG to simulate the welding of Al and Zr-BMG.The simulation results confirmed that the JH-2 constitutive model is feasible for the dynamic simulation of amorphous alloy.This thesis includes 36 figures,7 tables,and 145 referances.