铝合金板材温热成形性能

在20℃～300℃的温度范围内,分别对7B04-T6和6061-T6铝合金薄板进行了单拉试验,结果表明,7B04-T6高强度铝合金的断后延伸率和拉伸极限应变在温热状态下都有显著的提高,比较适合于温热成形,而6061-T6则不太适合。另外,基于Fields&Backofen本构方程,对7B04-T6在不同温度状态下的强化规律进行了分析和探讨,结果表明,随着温度的逐渐升高,应变强化指数n值不断减小,应变率敏感系数m值则显著增大,应变率强化明显增强,这也是在温热状态下其成形性能提高的主要原因。

Investigation of formability of aluminum alloy sheet at elevated temperature

The uniaxial tensile tests of 7B04-T6 and 6061-T6 aluminum alloy sheet were performed at various temperatures ranging from 20℃～300℃ in this study.It was found that,the ductility and limit tensile strain of 7B04-T6 high strength aluminum alloy were improved significantly at elevated temperature,so that 7B04-T6 is suitable for warm/hot forming.however,the 6061-T6 is not suitable for.In addition,hardening law of 7B04-T6 at different temperatures were analyzed and discussed based on Fields&Backofen constitutive equation.It was indicated that,the strain hardening index (n-value) was decreased with increasing temperature,while the strain rate sensitivity coefficient (m-value) was increased observably with increasing temperature,and that is the main cause accounting for the improvement of its formability at elevated temperature.