TiC/AZ91D镁基复合材料高温压缩变形行为

利用自发渗透原位合成法制备了不同体积分数的TiC增强AZ91D镁基复合材料，研究了不同压缩应变速率以及不同变形温度下复合材料的热变形行为，计算分析了不同温度下应变速率敏感指数(m)和表观激活能(Q)与TiC含量的关系．结果表明：TiC／AZ91D复合材料压缩流变应力随TiC含量的增加而升高；TiC含量相同时，流变应力随温度升高或初始应变速率减小而降低．m值随变形温度升高而增大；变形温度以及压缩应变速率相同时，m值随TiC含量升高而增大．Q值依赖于温度、应变速率和TiC含量及其分布，不同条件下其高温变形机制有所差异．

Compressive deformation behavior of TiC/AZ91Dcomposites at elevated temperatures

In situ reactive infiltration technique was utilizedto synthesis TiCparticulate-reinforced magnesium matrix composites(TiC/AZ91D). The hot compressivebehavior of as fabricated composites wasstudied at strain rates$dot{varepsilon} =10 -3-10 -1 s-1and at temperatures of 573-723 K. The strainrate sensitivity exponent ($m$), apparent activationenergy (Q) and their relations with TiC content andtemperature were calculated and analyzedaccording to the true stress-true strain curves.The results show that the compressive flow stressof the composites increases with increasingthe TiC content. For the same TiCcontent, the flow stress decreases withelevating deformation temperatures or with decreasingthe initial strain rates. The m value increases withincreasing temperature and at the samedeformation temperature and strain rate,the m value increases with increasing the TiC content.The Q value depends on the deformation temperature,strain rate and TiC content and itsdistribution, and the composites exhibitdifferent deformation mechanisms at elevatedtemperatures.