Experiment Study of Clinching Joint Process with Pre-forming between DP980 Ultra-high Strength Steel and AA5052 Aluminum Alloy Sheet
The work aims to investigate the effect of pre-formed clinching joint process parameters on the joint appearances and connection effect of ultra-high-strength steel and aluminum alloy sheets.Preformed clinching joint method was used to pre-form the steel sheet,reducing the problems of joint fracture or insufficient interlock due to excessive deformation resistance during clinching process.Meanwhile,a clinching punch with a pressure step structure was proposed to prevent aluminum alloy material from overflowing,further improving the clinching quality of the joint and compacting the joint.DP780 high strength steel,DP980 ultra-high strength steel,and AA5052 aluminum alloy sheet were selected as the research objects.The process pa-rameters such as pre-forming depth,die depth,and punch pressure step height were taken as variables.Clinching joint experi-ments were conducted with various combinations of variables to analyze the effect of process parameters on the joint appear-ances of DP780/AA5052 and DP980/AA5052.Finally,shear and peel strength experiments were conducted to evaluate the fea-sibility and effectiveness of pre-formed clinching joint of DP980/AA5052.Through microscopic inspection of the joints,it is found that with the increase of pre-forming depth and die depth,and the decrease of pressure step height,the interlock amount of the joint increases,with pre-forming depth having a greater impact.As the pre-forming depth and pressure step height decrease,and the die depth increases,the neck thickness of the joint increases,with die depth having a greater impact.Shear and peel strength experiments show that during shear test,the DP780/AA5052 joint exhibits peel and shear failure,while the DP980/AA5052 joint only exhibits peel failure.During peel test,both joints show aluminum plate tearing failure.A comparison of the shear strength of the two joints reveals that the DP980/AA5052 joint has higher connection strength than the DP780/AA5052 joint,confirming the feasibility of pre-formed clinching joint of ultra-high strength steel and aluminum alloy sheets.
pre-formingclinching jointDP980 ultra-high strength steelAA5052 aluminum alloypunch with pressure step
万方数据
维普
