In order to improve the mechanical properties of Al.Fe transition joints manufactured by explosive welding,meshing bonding interfaces were obtained by prefabricating dovetail grooves in base plates.The microstructure ...In order to improve the mechanical properties of Al.Fe transition joints manufactured by explosive welding,meshing bonding interfaces were obtained by prefabricating dovetail grooves in base plates.The microstructure and mechanical properties of the meshing interfaces were systematically investigated.The microstructure observation showed that metallurgical bonding without pores was created in the form of direct bonding and melting zone bonding at the interface.Fractography on tensile specimens showed cleavage fracture on the steel side and ductile fracture on the aluminum side near the interfaces.The tensile shear test results indicated that the shear strength of the meshing interface 0°and 90°was increased by 11%and 14%,respectively,when being compared to that of the ordinary Al.Fe transition joints.The values of microhardness decreased as the distance from the interface increased.After three-point bending,cracks were observed at the bonding interface for some specimens due to the existence of brittle Fe.Al compounds.展开更多
The effects of postweld heat treatment on the microstructure and metallurgical properties of a bronze–carbon steel(st37)explosively bonded interface were studied.Explosive welding was done under 1.5-and 2-mm standoff...The effects of postweld heat treatment on the microstructure and metallurgical properties of a bronze–carbon steel(st37)explosively bonded interface were studied.Explosive welding was done under 1.5-and 2-mm standoff distances and different conditions of explosive charge.Samples were postweld heat treated for 4 and 16 h in the furnace at 250°C and 500°C and then air cooled.Laboratory studies using optical microscopy,scanning electron microscopy,and microhardness testing were used to evaluate the welded samples.Microstructural examinations showed that by increasing the standoff distance and the explosive charge,the interface of bronze to steel became wavier.The microhardness test result showed that the hardness of the samples was higher near the joint interface compared with other areas because of the intensive plastic deformation,which was caused by the explosion force.The results show that increasing the heat treatment temperature and time caused the intermetallic compounds’layer thickness to increase,and,because of the higher diffusion of copper and tin,the iron amount in the intermetallic compounds decreased.Also,because of the increase in heat treatment temperature and time,internal stresses were released,and the interface hardness decreased.展开更多
基金Projects(51674229,51374189)supported by the National Natural Science Foundation of ChinaProject(WK2480000002)supported byFundamental Research Funds for Central Universities,China
文摘In order to improve the mechanical properties of Al.Fe transition joints manufactured by explosive welding,meshing bonding interfaces were obtained by prefabricating dovetail grooves in base plates.The microstructure and mechanical properties of the meshing interfaces were systematically investigated.The microstructure observation showed that metallurgical bonding without pores was created in the form of direct bonding and melting zone bonding at the interface.Fractography on tensile specimens showed cleavage fracture on the steel side and ductile fracture on the aluminum side near the interfaces.The tensile shear test results indicated that the shear strength of the meshing interface 0°and 90°was increased by 11%and 14%,respectively,when being compared to that of the ordinary Al.Fe transition joints.The values of microhardness decreased as the distance from the interface increased.After three-point bending,cracks were observed at the bonding interface for some specimens due to the existence of brittle Fe.Al compounds.
文摘The effects of postweld heat treatment on the microstructure and metallurgical properties of a bronze–carbon steel(st37)explosively bonded interface were studied.Explosive welding was done under 1.5-and 2-mm standoff distances and different conditions of explosive charge.Samples were postweld heat treated for 4 and 16 h in the furnace at 250°C and 500°C and then air cooled.Laboratory studies using optical microscopy,scanning electron microscopy,and microhardness testing were used to evaluate the welded samples.Microstructural examinations showed that by increasing the standoff distance and the explosive charge,the interface of bronze to steel became wavier.The microhardness test result showed that the hardness of the samples was higher near the joint interface compared with other areas because of the intensive plastic deformation,which was caused by the explosion force.The results show that increasing the heat treatment temperature and time caused the intermetallic compounds’layer thickness to increase,and,because of the higher diffusion of copper and tin,the iron amount in the intermetallic compounds decreased.Also,because of the increase in heat treatment temperature and time,internal stresses were released,and the interface hardness decreased.
