Al-4.4Cu/TiB2 composites were fabricated with and without post-in-situ reaction ultrasonic melt treatment. The structural and mechanical behaviors of the composites in both the as-cast (F) and T6—peak-aged conditions were analyzed and compared with the base alloy Al-4.4Cu. The microstructural result reveals that the ultrasonic-assisted processing enhanced the dispersion of nano-sized TiB2 particles. The ultrasonic treatment-assisted fabrication has improved the yield strength of Al-4.4Cu/2TiB2 composite about ~ 2 times over the monolithic Al-4.4Cu alloy in both the as-cast and peak-aged condition while retaining > 90 pct ductility of the matrix alloy. The various strengthening mechanisms operating in the materials, namely, base alloy, micro- and nanocomposite were discussed and the theoretical yield strength was estimated using appropriate equations. The theoretical yield strength estimates were found to correlate well with the experimental observations.

中文翻译：

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后原位反应超声处理制备的 Al-4.4Cu/2TiB2In-Situ 纳米复合材料的结构和力学行为

Al-4.4Cu/TiB2 复合材料经过和不经过原位反应后超声熔融处理制备。分析了复合材料在铸态 (F) 和 T6 峰值时效条件下的结构和力学行为，并与基合金 Al-4.4Cu 进行了比较。微观结构结果表明，超声辅助处理增强了纳米级 TiB2 颗粒的分散。超声处理辅助制造在铸态和峰值时效条件下将 Al-4.4Cu/2TiB2 复合材料的屈服强度提高了约 2 倍于整体 Al-4.4Cu 合金，同时保持了 > 90 pct 的延展性基体合金。在材料中起作用的各种强化机制，即基础合金、讨论了微米和纳米复合材料，并使用适当的方程估算了理论屈服强度。发现理论屈服强度估计值与实验观察结果很好地相关。