Abstract To improve the ductility of heat-resistant AlNp/Al composites, a strategy of hybrid particles with bimodal size distribution has been fabricated in this work. A series of hybrid Al matrix composites reinforced by nano AlN and submicron Al2O3 particles have been fabricated by liquid-solid reaction method and subsequent extrusion process. The effects of the submicron Al2O3 particles on the microstructure and tensile mechanical properties of the composites have been studied. Both nano AlN and submicron Al2O3 particles distributed homogeneously and well bonded with the Al matrix. Meanwhile, with the increase of the Al2O3 particles content, the ductility of (AlN + Al2O3)p/Al composites increased significantly without obvious sacrifice of ultimate tensile strength, and therefore a (AlN + Al2O3)p/Al composite with well-balanced strength and ductility was obtained. The ultimate tensile strength of (8.2AlN + 4Al2O3)p/Al composite at room temperature and high temperature (350 °C) can be up to 385 MPa and 150 MPa, and the total elongation can reach 14.6% and 5.0%, respectively. The strengthening and toughening mechanisms also have been discussed in detail.

中文翻译：

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亚微米Al2O3颗粒提高耐热AlNp/Al复合材料的延展性

摘要 为了提高耐热AlNp/Al复合材料的延展性，本工作制备了具有双峰尺寸分布的混合颗粒策略。采用液固反应法和后续挤压工艺制备了一系列纳米AlN和亚微米Al2O3颗粒增强的混合铝基复合材料。研究了亚微米Al2O3颗粒对复合材料微观结构和拉伸力学性能的影响。纳米 AlN 和亚微米 Al2O3 颗粒均匀分布并与 Al 基体结合良好。同时，随着Al2O3颗粒含量的增加，(AlN+Al2O3)p/Al复合材料的延展性显着增加，而极限抗拉强度没有明显牺牲，因此获得了强度和延展性平衡良好的 (AlN + Al2O3)p/Al 复合材料。(8.2AlN+4Al2O3)p/Al复合材料在室温和高温（350℃）下的极限抗拉强度可达385 MPa和150 MPa，总伸长率分别可达14.6%和5.0%。还详细讨论了强化和增韧机制。