论文部分内容阅读
结合2A70铝合金环件胀形工艺研究的需要,采用拉伸试验、扫描电镜、透射电镜研究胀形强化的微观机制。结果表明:经过胀形工艺的铝合金环件拉伸强度明显提高,但伸长率略有下降;胀形工艺为合金引入大量位错,有利于基体中空位和溶质的扩散,促进合金强化相—S相的均匀析出,并使无沉淀析出带变窄;大量弥散分布的S相缩小第二相质点间距,位错绕过质点应力增大,有利于提高合金的强度;较窄的无沉淀析出带会导致塑性下降。
Combined with the need of bulging process for 2A70 aluminum alloy ring, the microscopic mechanism of bulging was investigated by tensile test, SEM and TEM. The results show that the tensile strength of the aluminum alloy ring after bulging increases obviously, but the elongation decreases slightly. The bulging process introduces a large number of dislocations into the alloy, which is favorable for the diffusion of the hollow spaces and the solute in the matrix, -S phase, and the precipitation-free zone is narrowed. A large number of dispersed S phase reduce the spacing of the second phase particles, the stress of the dislocations around the particles increases, which helps to improve the strength of the alloy. The narrower precipitation-free zone Precipitation will lead to plasticity decline.