Effect of reinforcement particle size on quasistatic and dynamic mechanical properties of Al-Al2O3 composites
Effect of reinforcement particle size on quasistatic and dynamic mechanical properties of Al-Al2O3 composites
复制标题
增强体粒径对Al-Al2O3复合材料准静态和动态力学性能的影响
DOI：
10.1016/j.jallcom.2019.05.080
复制
发表时间：
2019-08-15
影响因子：
6.2
通讯作者：
An, Linan
中科院分区：
文献类型：
--
作者：
Liu, Jinling;Huang, Xinyu;An, Linan
本文采用高能球磨和热压合成了Al-15 vol.% mm Al2O3 (AlMMC)和Al-15 vol.% nm Al2O3 (Al-MMNC)复合材料，并系统研究了增强体粒径（3 mm和50 nm）对力学性能的影响。所制备的 Al-MMNC 样品具有比 Al-MMC 和纯 Al 更优异的机械性能，在准静态压缩下屈服强度和极限强度分别提高到 610 MPa 和 784 MPa。此外，Al-MMC和Al-MMNC的流变应力随着应变速率的增加而增加，并且由于粒径较小，Al-MMNC表现出比Al-MMC更高的流变应力。值得注意的是，在2200 s(-1)的加载速率下，Al-MMNC的极限强度达到963MPa。此外，与之前报道的铝基纳米复合材料不同，Al-MMNC表现出应变硬化和强应变率敏感性，这对于工程应用来说是非常理想的。最后，异位SEM分析表明Al-MMNC断裂表面存在微裂纹和韧窝，从而导致准静态压缩下的韧性断裂模式。此外，在Al-MMNC中也观察到了高应变率载荷下的绝热剪切，但高体积分数纳米粒子抑制了绝热剪切带的发展，导致应变硬化和强应变率敏感性。 (C) 2019 Elsevier B.V. 保留所有权利。
Herein, high-energy ball milling and hot pressing are employed to synthesize Al-15 vol.% mm Al2O3 (AlMMC) and Al-15 vol.% nm Al2O3 (Al-MMNC) composites and the influence of reinforcement particle size (3 mm and 50 nm) on mechanical properties has been systematically studied. The as-prepared Al-MMNC samples rendered superior mechanical properties than Al-MMC and pure Al, with an improved yield strength and ultimate strength of 610 MPa and 784 MPa under quasistatic compression, respectively. Moreover, the flow stress of Al-MMC and Al-MMNC increased with increasing strain rate, and Al-MMNC exhibited higher flow stress than Al-MMC due to the smaller particle size. It is worth noting that the ultimate strength of Al-MMNC reached 963MPa under the loading rate of 2200 s(-1). Moreover, unlike previously reported Al-based nanocomposites, Al-MMNC exhibited strain hardening and strong strain rate sensitivity, which is highly desirable for engineering applications. Lastly, the ex-situ SEM analysis revealed the presence of microcracks and dimples on the fractured surface of Al-MMNC, which led to the ductile fracture mode under quasistatic compression. Moreover, the adiabatic shear under high strain rate loading has also been observed in Al-MMNC, but the high volume fraction nanoparticles inhibit adiabatic shear band development, and result in strain hardening and strong strain rate sensitivity. (C) 2019 Elsevier B.V. All rights reserved.