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本文对Al-6.3Cu-0.29 Mn 合金的形变热处理、超塑性变形力学行为、显微组织、空洞及断裂等进行了研究。形变热处理可使耐热的Al-6.3Cu-0.29 Mn 合金的晶粒细化到9微米以下。合金在500℃以(?)=3.3×10~(-4)s~(-1)应变速率拉伸可呈现超塑性,延伸率达365%,流动应力为1.2MPa,m=0.76。第二相粒子的硬度、尺寸和分布是重要参数。小尺寸粒子对晶界有钉扎作用,可防止晶粒长大,大而硬的不易变形的粒子在变形中可能抑制晶界滑动,并因空洞而使试样早期断裂。
In this paper, Al-6.3Cu-0.29Mn alloy deformation heat treatment, superplastic deformation mechanical behavior, microstructure, porosity and fracture were studied. Deformation heat treatment can make the heat-resistant Al-6.3Cu-0.29Mn alloy grain refinement to 9 microns or less. The alloy shows superplasticity at 500 ℃ with strain rate of 3.3 × 10 ~ (-4) s ~ (-1), with elongation of 365%, flow stress of 1.2 MPa and m = 0.76. The hardness, size and distribution of the second phase particles are important parameters. Small particles have a pinning effect on the grain boundaries to prevent grain growth. Larger and harder, non-deformable particles may inhibit grain boundary sliding during deformation and cause early fracture of the specimen due to the void.