Research On Mechanical Clinching Technology Of AZ31Magnesium Alloy Sheets

The focus of this paper is on mechanical clinching technology of AZ31magnesium alloysheets, using a combination method of Finite Element Analysis (FEA) simulation and tests.First, by high temperature tensile tests, the plastic deformation behavior of AZ31magnesium alloy sheets are analyzed, the flow stress model is established after that. Secondly,the factors which may influence the FEA accuracy for the clinch joining process are studied,including CAE model, ALE adaptive meshing and boundary conditions. Then the simulationmodel is established in ABAQUS. Furthermore, the factors which may affect the quality ofclinching joints are discussed here, and then the scopes of clinching tool parameters aredetermined. Finally, the comparison of actual clinching tests and FEA simulation results showgood agreement of the clinched joints geometry. The main conclusions include:With Volume Calculation Methods, the suitable ranges of parameters for1mm thicknessof AZ31magnesium alloy sheets are determined and the parameters have been optimized.A new heating method called Die Heating is introduced in this paper. The designeddevice includes heating spring and intelligent temperature controlling system. Its feasibilityand rationality are verified by clinching tests.For clinching tests, the suitable range of die temperature is250°C to350°C. In general,too low temperature will leads to crack formation in the neck, but too high temperature willresults in failure in the bottom of joints. The best die temperature is300°C. The tensile testsare carried out to evaluate the strength of the mechanical clinched joints by the proposeddesign method.The results will provide a theoretical and experimental basis for AZ31magnesium alloysheets clinching technology. The implementation of research results will help to promote theapplication of magnesium alloys in automotive lightweight, and support the development ofChina’s automobile manufacturing process.