轧制与增强体对铝基复合材料超塑性的影响

Effects of Rolling and Reinforcement on Superplasticity of Aluminum Matrix Composites

对比研究了轧制与陶瓷增强体对SiCw／LY12和SiCp／LY12超塑性的影响，分析了超塑性差异的原因。研究表明：SiCw／LY12经623K热轧后，展现出好的高应变速率的超塑性，其超塑性变形的主要机制是适当的微量液相调节的细小晶粒的晶界滑动（晶粒尺寸约为1～3μm），但经进一步的冷轧后，超塑性明显下降；SiCp／LY12在仅经623K热轧后，不出现超塑性；但经进一步的冷轧后，展现出常规应变速率的超塑性，超塑性变形的机制是适当的微量液相和动态回复共同调节的晶界滑动（晶粒尺寸约为10μm）。

A comparative study on the effects of rolling and reinforcement on superplasticity in a SiCw/LY12 composite and a SiCp/LY12 composite was carried out, and the causes of differences in superplasticity were analyzed. Results show: SiCw/LY12 exhibited ed high -strain - rate superplasticity after hot rolling at 623 K, which is supposed to be caused by grain boundary slip of fine grains (1～3μp) assisted by the existence of a small amount liquid phase, and the superplasticity showed significant decrease after subseqUent cold rolling; SiC,/LY12 did not exhibit superplasticity after hot nilling at 623 K, but it exhibited normal --strain - rate superplasticity after subsequent cold rolling, which is supposed to be caused by grain boundary (with a grain size of about 10 μp)slip assisted by dynamic recovery and the existence of a small amount of liquid phase.