7075铝合金高温变形及损伤极限

High temperature deformation and damage limit of 7075 aluminum alloy

在350、400和450℃温度下,对7075铝合金拉伸试样进行了应变速率0.001、0.01和0.1s-1的恒应变速率法拉伸试验;对预缩颈试样进行了速度为0.9和9mm·min-1的恒速拉伸试验;利用DEFORM-2D有限元软件对恒速拉伸过程进行模拟。结果表明:变形温度为影响7075铝合金断裂极限的主要因素;7075铝合金在研究温度范围内C^L损伤模型临界损伤值在0.79~1.42范围内变化;棒料拉伸过程中损伤值由中心向表面逐渐减小。

The tensile tests of 7075 aluminum alloy tensile samples were conducted at 350, 400 and 450 ℃ and strain rate range of 0. 001, 0.01 and 0.1 s 1 by using constant strain rate tensile method. And the tensile tests of prefabricated necking samples were conducted in the speed range of 0. 9 and 9 mm · min-1 by using constant speed tensile method. The fracture process of constant speed tensile was simulated by DEFORM-2D. The result shows that the fracture limit of 7075 aluminum alloy is mainly affected by deformation temperature, the C-L critical damage value of 7075 aluminum alloy changes from 0. 79 to 1.42, and the damage value decreases from the center to the surface of cylindrical samples.