Experimental And Simulation Study On Heat Transfer Coefficient In Hot Stamping Of 6082 Aluminum Alloy

With the rapid development of automobile industry, reducing fuel consumption and vehicle emissions has become the development trend of world auto industry. Automotive lightweighting can reduce the weight of the car so that decrease fuel consumption and reduce exhaust emissions. Auto lightweight usually use three kinds of measures, including lightweight materials, optimize the structure of automobile and new technology, lightweight materials is the most effective way to realize automotive lightweighting.Aluminum alloy hot stamping process as a kind of important way of realizing auto lightweight. on the one hand, it can improve the poor forming, crack and springback of aluminium alloy; on the other hand, it can solve the problem of heat treatment deformation by the mold pressure-keeping quenching, and the mechanical properties of materials were increased significantly by aging treatment. Interface heat transfer coefficient(IHTC) as the key factors of heat transfer in hot stamping process can influence the temperature distribution,microstructure, stress field. IHTC is also very important parameter in simulating hot stamping workpiece cooling process, so the accurate measurement and calculation of the IHTC will provide reliable data for numerical simulation of support.The article studies the temperature change of 6082 aluminum alloy and die under different pressure and different temperature conditions in the process of hot stamping. We used finite element software to carry on the numerical simulation of hot stamping, and calculated the IHTC by optimization software. The conclusions are as follows:1 、 The experimental apparatus was developped, which not only heated mold, but also collectted the temperatue of blank and die in the process of hot stamping.2、The blanks were put in the mold with hot stamping-queching technology for 10 secondsunder different pressure and different mold temperature; the temprature changes of blank and die were collected in the hot satmping process. The cooling speed of blank was analyzed under the condition of different pressure and die temperature.3、We used the finite element analysis software to simulate hot stamping quenching of blank,analyzed temperature distribution of blank in the process of hot stamping-quenching and output the simulated temperature curve of blank and die. IHTC was calculate by optimization software that optimized temperature change curves between simulation and experiment. The temperature-IHTC and pressure-IHTC were obtained.