Al/Al2O3复合材料的伪半固态压缩变形力学行为

对37%Al/Al2O3复合材料坯料进行高温压缩,研究其伪半固态压缩变形力学行为.结果表明,该材料在伪半固态温度下的高温压缩过程中,真实应力-真实应变曲线存在四个变化阶段:急剧上升-下降-平稳-缓慢上升,且稳态流动应力及峰值应力随着温度的提高和应变速率的降低显著下降,说明该材料具有应变速率和变形温度敏感性.随着变形量的增加,微观组织中的孔洞逐渐增多.

Al/Al2O3 composite mechanical behaviour of compression in pseudo-semi-solid sate

The relationship curves between true stress and true strain of the 37%Al/Al2O3 composite have four stages during the process. That is ascending rapidly, descending, steady and ascending gradually. Steady flow stress and peak stress decrease evidently with temperature increase and the stain rate decrease. It declares that it has sensitivity of strain rate and deformation temperature. By the observation of microstructure, it shows that with the deformation increase, the micro holes in the billets increase gradually. It indicates correctly the mechanical behavior of composite in pseudo-semi-solid temperature. And it establishes the foundation for mastering the thixo-forging of Al/Al2O3 composite in pseudo-semi-solid state.