Study on statics properties of steel/aluminum clinch-bonded composite joint under corrosive environment
In order to explore the statics properties of aluminum alloy clinched joints and the effect of the corrosion on the statics properties of clinch-bonded composite joints,the AA5052 aluminum alloy and the DP590 dual-phase steel were used as test plates to prepare the clinched joints and the clinch-bonded composite joints with aluminum/aluminum and steel/aluminum combinations,respectively.The statics properties and the failure mechanism of joints were analyzed by the tensile test and the scanning electron microscope.Then,the 0.02 mol/L NaHSO3 solution was used as corrosion medium to perform alternate immersion accelerated corrosion tests on the joint specimens with the best statics properties.The results showed that the statics properties of clinched joints and clinch-bonded composite joints could be improved by selecting the higher strength plate as the upper plate,and the failure modes of the two joints were optimized from the neck-fracture to the mixing of bottom pull-out and neck-fracture.The use of adhesive could improve the statics properties of clinched joints,but had no significant effect on their failure mode.In the acidic environment,the failure mode of the steel/aluminum clinch-bonded composite joints gradually transformed from the mixing of bottom pull-out and neck-fracture to the neck-fracture,indicating that the corrosion aging would cause the neck of the upper plate to become thin,and make it become a weak link in the shear transfer process and fracture.During the corrosion process,the peak load of the steel/aluminum clinch-bonded composite joint showed a decreasing trend,and the energy absorption value showed a"step"decline.The decrease of peak load and energy absorption value of the steel/aluminum clinch-bonded composite joint was small in the medium and long corrosion period,which indicated that the corrosion accumulated on the surface of the plate could inhibit the corrosion effect of joints.The research results can provide reference for the subsequent design and evaluation of automotive lightweight.
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维普
