Abstract The wear resistance and microhardness behavior of hybrids consisting of wrought aluminum alloy AA7075 with different volume fractions of SiC and BN nano-powders were investigated experimentally. The surfaces of the hybrid nanocomposites were fabricated by friction stir processing (FSP). The microstructure of the reinforcement nano-powders and fabricated nanocomposite surface were examined using scanning electron microscopy (SEM) and high-resolution polarized optical microscopy. The wear resistance and microhardness tests were performed on the specimens before and after the fabrication process. The AA7075 showed a large grain size with an average of 178 μm, while the hybrid composites of AA7075/SiC-BN showed finer grains with an average size of 8 μm due to the FSP parameters. Additionally, a good nano-particle surface dispersion was clearly visible with nearly no voids. The wear resistance results showed that the addition of SiC and BN nano-particles increased the fabricated nanocomposite surface wear resistance by 53-61%. It was also noted that the wear resistance rate had a clearly inverse relationship with the increasing mass fraction of the nano-particles. The presence of SiC and BN nano-particles also increased the hardness by an average of 45%. The volume fraction of the reinforced nanoparticles had a significant impact on the mechanical and wear properties of the fabricated hybrid nanocomposite surfaces.

中文翻译：

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搅拌摩擦加工制备的AA7075/SiC-BN杂化纳米复合材料表面的磨损和显微硬度行为

摘要 通过实验研究了不同体积分数的碳化硅和氮化硼纳米粉体的变形铝合金AA7075复合材料的耐磨性和显微硬度行为。混合纳米复合材料的表面通过搅拌摩擦加工（FSP）制造。使用扫描电子显微镜 (SEM) 和高分辨率偏振光学显微镜检查增强纳米粉末和制备的纳米复合材料表面的微观结构。在制造过程之前和之后对试样进行耐磨性和显微硬度测试。由于 FSP 参数，AA7075 显示出平均为 178 μm 的大晶粒尺寸，而 AA7075/SiC-BN 的混合复合材料显示出平均尺寸为 8 μm 的细晶粒。此外，良好的纳米颗粒表面分散清晰可见，几乎没有空隙。耐磨性结果表明，SiC和BN纳米颗粒的加入使制备的纳米复合材料的表面耐磨性提高了53-61%。还注意到耐磨速率与纳米颗粒质量分数的增加具有明显的反比关系。SiC 和 BN 纳米颗粒的存在也使硬度平均提高了 45%。增强纳米颗粒的体积分数对制备的混合纳米复合材料表面的机械和磨损性能有显着影响。还注意到耐磨速率与纳米颗粒质量分数的增加具有明显的反比关系。SiC 和 BN 纳米颗粒的存在也使硬度平均提高了 45%。增强纳米颗粒的体积分数对制备的混合纳米复合材料表面的机械和磨损性能有显着影响。还注意到耐磨速率与纳米颗粒质量分数的增加具有明显的反比关系。SiC 和 BN 纳米颗粒的存在也使硬度平均提高了 45%。增强纳米颗粒的体积分数对制备的混合纳米复合材料表面的机械和磨损性能有显着影响。