Study On Dynamic Impact Response Behavior Of Explosively Welded Cu/Al Laminated Material

With the development of the automobile,aerospace and national defense industries,the requirements for material structure performance are becoming higher and higher.Single component materials have been difficult to meet the needs of social development.Composite materials with better specific strength,stiffness and excellent comprehensive performance have been the darling of the new era.Copper/aluminum laminated composite has been widely studied and applied for combining the high conductivity,thermal conductivity of copper with the lightness,corrosion resistance and economy of material aluminum.In this paper,the explosive welding process of T2 pure copper and 2024 aluminum alloy was studied.And the microstructure and mechanical properties of the interface were analyzed.Through the quasi-static and dynamic compression experiments at room temperature,the response characteristics under different structural forms were studied respectively.In addition,the SHPB experiments were simulated by the ABAQUS finite element software.The investigation contents of this paper show below:(1)The copper/aluminum laminates has been successfully realized by explosive welding process through the selection of appropriate parameters.Through the research of microstructure,it can be seen that the interface of Cu/Al joint presents a typical wavy morphology and a clear intermediate transition layer appears in the interface area during the explosive cladding process.Due to the formation of brittle intermetallic compounds in these area,the hardness is significantly higher than that of the raw material.In addition,the micro-cracks in the intermediate melting layer also show some bonding defects.(2)The static and dynamic experiments of laminated structure are carried out by using electronic universal testing machine and SHPB device.The experimental results show that the mechanical properties of the specimen structure with compression direction parallel to the bonding interface(parallel structure)are better than those with compression direction perpendicular to the bonding interface(series structure).(3)Constructing a simplified mathematical and physical model of the laminated structure,and analyze the propagation characteristic of stress wave based on the basic theory of the stress wave.The results show that the shear effect will occur at the consolidation interface due to the mismatch of wave impedance in the parallel structure;For the series structure,only exists the wave reflection-transmission effect and the superposition of disturbances.(4)The numerical simulation model of SHPB experiment is established with the software ABAQUS.The represent data from strain gages on the incident and transmitted bars is good consistency between the model and experiment,showing that numerical simulation accurately captures the details of wave propagation.Through the simulation results,it can be seen that there is stress gradient inside the series structure,and there is a sudden change in the stress value at the interface;While for the parallel structure,the internal stress distribution is relatively uniform on both sides of the specimen,but there is a stress gradient between different materials.