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为了研究多重纳米结构对块体材料强化和变形能力的影响机制,采用粉末冶金法制备了多重纳米结构的B4C颗粒增强铝基复合材料,并对复合材料的强化和形变破坏机制进行了定量和定性的讨论。由100%球磨复合粉末制备的块体复合材料的室温压缩强度为670MPa;当加入10vol%气雾化态的Al2024粉末后,复合材料的室温压缩强度升高到1.115GPa;之后随着气雾化态Al2024粉末含量的增加,复合材料的强度逐渐下降,但是没有产生明显的塑性变形;当气雾化态Al2024粉末的含量增加到50vol%时,复合材料的压缩强度下降到580MPa,断裂前变形率达到了10%。扫描电镜(SEM)和透射电镜(TEM)的分析结果显示,亚微米级的B4C颗粒、位错以及纳米晶基体分别通过Orowan强化、位错强化和细晶强化机制对复合材料进行强化;粗晶Al2024区域与复合结构区域的比例显著影响复合材料的形变及破坏机制。
In order to study the mechanism of the effect of multiple nanostructures on the strengthening and deformability of bulk materials, a multi-nanostructured B4C particle reinforced aluminum matrix composite was prepared by powder metallurgy method. The mechanism of strengthening and deformation failure of the composite was quantified and characterized discussion. The compressive strength at room temperature of the bulk composites prepared by 100% ball milling composite powder is 670MPa. After adding 10vol% Al 2 O 4 powder in the gas atomized state, the compressive strength at room temperature of the composites increases to 1.115GPa; When the content of Al2024 powder increases, the strength of the composite decreases gradually, but no obvious plastic deformation occurs. When the content of Al2024 powder increases to 50vol%, the compressive strength of the composites decreases to 580MPa. The deformation rate before fracture Reached 10%. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis of the results show that submicron B4C particles, dislocations and nanocrystalline matrix respectively by Orowan strengthening, dislocation strengthening and fine grain strengthening mechanism of the composite material strengthening; coarse The ratio of Al2024 area to composite structure area significantly affects the deformation and failure mechanism of composites.