【摘要】 通过对比原位TiB₂颗粒增强铝基复合材料和基体合金的时效行为，研究了TiB₂颗粒对时效行为的影响以及颗粒促进时效沉淀的机制。此外，还研究了时效过程中TiB₂/Al-4.5Cu复合材料和基体合金的拉伸性能和硬度的变化。结果表明，TiB₂颗粒加速了复合材料的时效过程，同时TiB₂颗粒附近的高密度位错导致了Al₂Cu相的不均匀析出。相较于基体合金，TiB₂/Al-4.5Cu复合材料的峰时效时间由20 h缩短至8 h。复合材料力学性能随时效时间的变化可以分为2个阶段，这与Al₂Cu析出相的变化具有良好的一致性。复合材料的屈服强度比时效前提高了24%，比时效的基体合金提高了82%。更多还原

【Abstract】 The influence of TiB₂ particles on aging behavior and mechanism of particles promoting aging precipitation were systematically explored by comparing aging behavior of in-situ TiB₂ particle reinforced aluminum matrix composites and matrix alloy. The variation of tensile properties and hardness of TiB₂/Al-4. 5Cu composites and matrix alloy during the aging process were investigated. The results indicate that TiB₂ particles can accelerate the aging process of the composites, while high-density dislocations near TiB₂ particles lead to uneven precipitation of Al₂Cu phase. Compared to the matrix alloy, the peak aging time of TiB₂/Al-4. 5Cu composite is shortened from 20 h to 8 h. Mechanical property variation of the composites with aging time can be divided into two stages, which is consistent with the transformation in Al₂Cu precipitates. The yield strength of composites is increased by 24% compared to that of one before aging, and increased by 82% compared to that of aged matrix alloy.更多还原