Abstract Aluminum matrix Boron carbide composites is an important thermal neutron shielding material. In order to prepare 12 wt% B4C/6061Al composite with higher mechanical properties by powder metallurgy method, the new composite reinforced by Nano-Al2O3 particles was fabricated by hot isostatic pressing in the semi-solid temperature range. The tensile properties and strengthening effects of the composite were investigated in this research. The tensile stress-strain curve of the composites was tested by material testing machine, and the microstructure and tensile fracture morphology of composites were analyzed by scanning electron microscopy (SEM) and transmission electron microscopes (TEM). The results indicated that the tensile strength of the composite was greatly improved by the addition of Nano-Al2O3, but the elongation decreased obviously. Nano-Al2O3 particles had seriously affected the microstructure and fracture morphology of the composite and lead to the more obvious brittle fracture characteristics. Strengthening mechanisms of Nano-Al2O3 particles reinforced 6061Al/B4C composite have been discussed, which reveals that grain boundary strengthening mainly plays the most important role.

中文翻译：

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纳米Al 2 O 3 颗粒增强6061Al/12wt.%B4C复合材料的拉伸性能及强化效果

摘要 铝基碳化硼复合材料是一种重要的热中子屏蔽材料。为了通过粉末冶金方法制备具有更高力学性能的12 wt% B4C/6061Al复合材料，在半固态温度范围内通过热等静压制备了纳米Al2O3颗粒增强的新型复合材料。本研究对复合材料的拉伸性能和强化效果进行了研究。采用材料试验机测试复合材料的拉伸应力-应变曲线，采用扫描电镜（SEM）和透射电镜（TEM）分析复合材料的显微组织和拉伸断口形貌。结果表明，纳米Al2O3的加入大大提高了复合材料的抗拉强度，但伸长率明显下降。纳米Al2O3颗粒严重影响了复合材料的微观结构和断口形貌，导致更明显的脆性断裂特征。讨论了纳米Al2O3颗粒增强6061Al/B4C复合材料的强化机制，表明晶界强化主要起最重要的作用。