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文中阐述了中间退火时间对 P/M 铝合金超塑性的影响。这种用快速凝固粉末而制成的Al—Zn—Mg—Cu 合金中锆含量较高。粉末在713K 时热挤压成条状。这些条在623K 时分别退火7.2,28.8和180Ks 并在室温下轧制。这些试样延长至断裂时的延伸率大于1500%没有背压而且超塑性的最佳初应变速率在788K 时大约为10~(-1)S(-1)。但是,在长时间退火的试样中,延伸率和 m 值低而且试样的晶粒尺寸在动态再结晶之后比短时间退火的大。晶粒在超塑性变形时出现长大造成超塑性变形时产生位借共格Al_3Zr 颗粒减少从而抑制了再结晶的溶质 Zr 原子减少。在用正确工艺加工的材料中,膨胀成形可在20秒内完成。
The effect of intermediate annealing time on the superplasticity of P / M aluminum alloy is described in this paper. The high content of zirconium in Al-Zn-Mg-Cu alloys made with rapidly solidified powders. The powder was hot extruded into strips at 713K. The strips annealed 7.2, 28.8 and 180 Ks respectively at 623 K and were rolled at room temperature. These samples were extended to fracture elongation greater than 1500% without backpressure and the optimal initial strain rate for superplasticity was about 10-1 S (-1) at 788K. However, in the samples annealed for a long time, the elongation and the value of m were low and the grain size of the sample was larger than that after annealing for a short time after dynamic recrystallization. When the superplastic deformation occurs, the grains grow and cause superplastic deformation, which reduces the solute Zr atoms by reducing the amount of the conformal Al_3Zr particles and restraining the recrystallization. In the correct process of processing materials, the expansion forming can be completed within 20 seconds.