Ti-6Al-4V alloy (TC4) with different concentrations of graphene nanoplatelets (GNPs) were fabricated by ball milling and spark plasma sintering (SPS). Microstructure characteristics of the composites were characterized by X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), and Raman. Microhardness and the compressive mechanical properties were also investigated. Experimental results showed that in the process of SPS, most of the GNPs were still retained at high pressure and temperature, and a new phase of TiC was presented due to the in-situ reaction between TiC and GNPs. Also, the strength of the composites was depended on the concentration of GNPs in TC4 matrix. Consequently, the composite with 0.8 wt. % GNPs was increased 18% in microhardness. The maximum yield strength and ductility of the composite were increased by 22.2% and 43.2%, respectively. The strengthening mechanism of the composites was further discussed, and the Orowan strengthening mechanism was the main strengthening factor.

中文翻译：

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火花等离子体烧结合成石墨烯增强Ti-6Al-4V复合材料的微观结构演变和力学性能

通过球磨和火花等离子体烧结（SPS）制备了具有不同浓度石墨烯纳米片（GNPs）的Ti-6Al-4V合金（TC4）。通过X射线衍射（XRD），扫描电子显微镜（SEM）和拉曼表征了复合材料的微观结构特征。还研究了显微硬度和压缩机械性能。实验结果表明，在SPS过程中，大多数GNP仍保留在高温高压下，由于TiC与GNP之间的原位反应，出现了新的TiC相。而且，复合材料的强度取决于TC4基质中GNP的浓度。因此，具有0.8重量％的复合材料。GNPs百分比的显微硬度提高了18％。复合材料的最大屈服强度和延展性分别提高了22.2％和43.2％，分别。进一步讨论了复合材料的增强机理，其中Orowan增强机理是主要的增强因素。