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为揭示磁脉冲成形的增塑机制,采用理论分析与微观组织观察相结合的方法对5052铝合金板材磁脉冲动态拉伸过程中动态成形行为和塑性失稳机制进行了系统研究.结果表明,惯性力在动态成形中起主要作用,惯性力对试样的结构失稳具有抑制作用,从而使试样的塑性提高并产生分散失稳;5052铝合金动态成形和准静态成形的成形性质相似,不会产生特殊的组织结构,塑性变形机制均为位错滑移机制;准静态成形过程以均匀单系位错滑移为主,断裂伴随着位错的缠结和攀移;而动态成形过程中,位错滑移趋于多系开动,在大面积区域出现明显的交滑移现象,且滑移带较准静态成形时窄且密,位错组态更均匀;动态成形的多系滑移和位错均化作用可在比准静态成形高的多的塑性应变水平下形成,从而使材料表现出较高的塑性和强度.
In order to reveal the plasticizing mechanism of magnetic pulse shaping, the dynamic forming behavior and plastic instability mechanism of 5052 aluminum alloy sheet under dynamic magnetic pulsation were systematically studied by the combination of theoretical analysis and microstructure observation.The results show that the inertia Force plays a major role in dynamic forming. The inertial force has an inhibitory effect on the structural instability of the sample, so that the plasticity of the sample increases and dispersion instability occurs. The forming properties of 5052 aluminum alloy are similar to those of quasi-static forming Which will produce a special organizational structure, plastic deformation mechanism are dislocation slip mechanism; Quasi-static forming process to uniform single-family dislocation slip, fracture accompanied by dislocation entanglement and climbing; and dynamic forming process , The dislocation slip tends to be multi-system start-up, obvious cross-slip occurs in a large area, and the slip band is narrower and more dense than the quasi-static forming, and the dislocation configuration is more uniform. The dynamic multi-line slip And dislocation homogenization can be formed at much higher levels of plastic strain than quasi-static forming, resulting in higher plasticity and strength of the material.