7050铝合金等通道转角挤压的有限元模拟及力学性能

Mechanical Properties and Finite Element Simulation of Equal Channel Angular Pressing of 7050 Al Alloy

采用有限元技术模拟7050Al合金等温等通道转角挤压过程,得到摩擦系数、挤压速度和挤压转角等挤压参数对7050Al合金变形区的应变分布和挤压载荷的影响规律。结果表明:挤压转角和摩擦系数对材料变形区的应变和挤压载荷的影响较大,挤压转角越小、摩擦系数越大时材料变形区的应变值越大,挤压载荷也越大;挤压速度对材料的应变和挤压载荷的影响很小。对经过挤压的材料进行拉伸实验,结果表明:在挤压初期,材料的抗拉强度随挤压次数的增加而很快增加,此后随挤压次数增加基本达到一恒定值,挤压转角越小材料的强度值增加越大。在单次挤压后,材料的延伸率很快下降,此后随挤压次数增加延伸率有回升的趋势。

With the help of finite element method, the effect of different process variables on the distribution of equivalent strain, deformation, extrusion load of 7050 Al alloy during the isothermal equal channel angular pressing was studied. Process variables considered friction factor, channel angle and punch velocity. The results showed that the equivalent strain and extrusion load were greatly affected by the friction factor and channel angle, the punch velocity had little effect on the equivalent strain and extrusion load. The equivalent strain and extrusion load increased with increasing friction factor, and with decreasing channel angle. Experiments discovered that the ultimate strength increased with increasing extrusion passes, and then changed little with extrusion passes after by 4 passes, ultimate strength increased with decreasing channel angle. Elongation decreased greatly after by 1 pass, and then increased little with increasing extrusion passes.