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摘自《日經力》5(1989),1,92～94. 为了显示超塑性现象一般要求合金具备三个条件:(1)形成粒径约数微米的等轴晶粒组织,并且在变形过程中晶粒组织必须不因热作用而粗化;(2)变形速度在10~(-3)～10~(-5)/s范围以内,超出此范围就会使得延伸率减小;(3)超塑性加工温度高于其熔点绝对温度的1/2,即处于其超塑性温度范围以内,超出此范围则不利于超塑性变形。另外还有在合金加热或冷却过程中相变时显示超塑性的“相变超塑性”。超塑性成型特別有利于在难加工材料的复杂形状成型加工。铝合金、钛合金和镍合金的超塑性加工件,已
Excerpt from “Nikkei” 5 (1989), 1,92 ~ 94. In order to show the superplastic phenomenon generally requires three conditions for the alloy: (1) the formation of grain size of about several microns of equiaxed grain structure, and in the deformation process The grain structure must not be roughened by heat; (2) the deformation rate is within the range of 10 -3 to 10 -5 / s beyond which the elongation will decrease; 3 ) Superplastic processing temperature is higher than its absolute melting point temperature 1/2, that is, in its superplastic temperature range, beyond this range is not conducive to superplastic deformation. There is also a “phase change superplasticity” that shows superplasticity when the alloy is heated or cooled during phase change. Superplastic forming is particularly beneficial for the complex shape forming of difficult-to-machine materials. Aluminum, titanium and nickel alloy superplastic processed pieces, have