Microstructure and high strain rate superplasticity of in situ composite synthesised from aluminium and nano-ZrO2 particles by powder metallurgy

作者：Geng L^*; Imai T; Mao JF; Takagi M; Yao CK

来源：Materials Science and Technology, 2001, 17(2): 187-194.

Pure aluminium matrix composites reinforced mainly with a fine needle-like Al3Zr phase were synthesised by the reaction between nanocrystalline ZrO2 particles and pure aluminium using powder metallurgy followed by hot extrusion and hot rolling. After extrusion, the composite fabricated,vith 5 vol.-%ZrO2 had a strain rate sensitivity (nr value) of 0.31 and a total elongation of 156% at 650 degreesC and 1.3 x 10(-1) s(-1). The high strain rate superplasticity was improved by hot rolling. After hot rolling, the m value of the composite fabricated with 10%ZrO2 particles was 0.40 and the total elongation was 204% at 640 degreesC and 1.3 x 10(-1) s(-1). The superplastic deformation mechanism for the present composites involves grain boundary sliding and interfacial sliding. From this mechanism, the following experimental results can be easily understood: the total elongation increased with temperature, and the strain rate at which maximum total elongation was attained increased with increasing deformation temperature.

• 出版日期2001-2
• 单位哈尔滨工业大学