The deformation mechanism of carbon nanotubes (CNTs) reinforced Al (CNT/Al) composites at room temperature is yet to be discovered. In this study, CNT/Al composites and ultrafine-grained (UFG) Al prepared by flake powder metallurgy were subjected to strain rate jump tests to study the effect of CNTs on the deformation mechanism of the UFG Al. The results showed that the addition of CNTs greatly influenced the deformation behavior and microstructure, and with CNTs increasing from 0 to 2 vol pct, the strain rate sensitivity increased from 0.015 to 0.024, while the apparent activation volume decreased from 71.7 b³ to 39.3 b³. This phenomenon originated from both the CNTs constrained grain refinement and the increasing dislocation density caused by CNTs, nanocrystalline grains, and intragranular Al₄C₃. Thermal activation analysis indicated that the rate-controlling mechanisms of both the UFG Al and CNT/Al composites were the forest dislocation cutting. This work may provide insight into stabilizing uniform tensile deformation by increasing strain rate hardening in metal matrix composites.

碳纳米管（CNTs）增强的铝（CNT / Al）复合材料在室温下的变形机理尚未发现。本研究对片状粉末冶金制得的CNT / Al复合材料和超细Al（UFG）Al进行了应变速率跳跃试验，研究了CNTs对UFG Al变形机理的影响。结果表明，添加CNT的极大地影响了变形行为和显微组织，并用的CNT从0到2体积PCT的增加，应变速率灵敏度从0.015增加至0.024，而表观活化体积从71.7下降b ³到39.3 b ³。这种现象既源于CNT约束晶粒细化，又源于CNT，纳米晶粒和晶粒内Al ₄ C ₃引起的位错密度增加。热活化分析表明，UFG Al和CNT / Al复合材料的速率控制机制都是森林位错切割。这项工作可以通过增加金属基复合材料的应变速率硬化来提供稳定均匀拉伸变形的见识。