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对Cu-0.54%Al2O3弥散强化复合材料的拉伸变形和断裂行为进行了研究。结果表明,经挤压比为30∶1的热挤压后,复合材料的σb、σ0.2、δ和σ0.2/σb分别高达340MPa、250MPa、24%和74%。冷加工后合金的强度随退火温度的升高而逐渐下降,但σ0.2/σb仍保持较高的值。挤压态合金的加工硬化指数n为0.256,明显低于纯铜。铜基体中均匀弥散分布着平均尺寸为18nm,间距为100nm的Al2O3纳米粒子,提高了铜基体的强度,阻碍了高温退火时再结晶的发生,降低了合金的加工硬化速率。挤压态合金的拉伸断口宏观上为杯锥状,微观上表现为明显的韧性断裂特征。
The tensile deformation and fracture behavior of Cu-0.54% Al2O3 dispersion-strengthened composites were studied. The results show that the σb, σ0.2, δ and σ0.2 / σb of the composites are as high as 340MPa, 250MPa, 24% and 74% respectively after hot extrusion with the extrusion ratio of 30:1. After cold working, the strength of the alloy decreases gradually with the increase of annealing temperature, but σ0.2 / σb still maintains the higher value. Extruded alloy work hardening index n is 0.256, significantly lower than pure copper. Al 2 O 3 nanoparticles uniformly distributed in the copper matrix with an average size of 18 nm and a pitch of 100 nm increased the strength of the copper matrix and hindered the recrystallization during high temperature annealing and reduced the work hardening rate of the alloy. Extruded alloy tensile fracture macroscopically cup-shaped cone, the microscopic performance of the obvious ductile fracture characteristics.