Haghighi Milad, Shaeri Mohammad Hossein, Sedghi Arman, Djavanroodi Faramarz
Department of Materials Science and Engineering, Imam Khomeini International University (IKIU), Qazvin 3414916818, Iran.
Mechanical Engineering Department, Prince Mohammad Bin Fahd University, Al Khobar 31952, Saudi Arabia.
Nanomaterials (Basel). 2018 Dec 8;8(12):1024. doi: 10.3390/nano8121024.
The effect of graphene nanosheet (GNS) reinforcement on the microstructure and mechanical properties of the titanium matrix composite has been discussed. For this purpose, composites with various GNS contents were prepared by cold pressing and sintering at various time periods. Density calculation by Archimedes' principle revealed that Ti/GNSs composites with reasonable high density (more than 99.5% of theoretical density) were produced after sintering for 5 h. Microstructural analysis by X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM) showed that TiC particles were formed in the matrix during the sintering process as a result of a titanium reaction with carbon. Higher GNS content as well as sintering time resulted in an increase in TiC particle size and volume fraction. Microhardness and shear punch tests demonstrated considerable improvement of the specimens' mechanical properties with the increment of sintering time and GNS content up to 1 wt. %. The microhardness and shear strength of 1 wt. % GNS composites were enhanced from 316 HV and 610 MPa to 613 HV and 754 MPa, respectively, when composites sintered for 5 h. It is worth mentioning that the formation of the agglomerates of unreacted GNSs in 1.5 wt. % GNS composites resulted in a dramatic decrease in mechanical properties.
讨论了石墨烯纳米片（GNS）增强对钛基复合材料微观结构和力学性能的影响。为此，通过在不同时间段进行冷压和烧结制备了具有不同GNS含量的复合材料。根据阿基米德原理进行密度计算表明，烧结5小时后制备出了具有合理高密度（超过理论密度的99.5%）的Ti/GNSs复合材料。通过X射线衍射（XRD）和场发射扫描电子显微镜（FESEM）进行微观结构分析表明，在烧结过程中，由于钛与碳发生反应，在基体中形成了TiC颗粒。较高的GNS含量以及烧结时间导致TiC颗粒尺寸和体积分数增加。显微硬度和剪切冲孔试验表明，随着烧结时间和GNS含量增加至1 wt.%，试样的力学性能有显著改善。当复合材料烧结5小时时，1 wt.% GNS复合材料的显微硬度和剪切强度分别从316 HV和610 MPa提高到613 HV和754 MPa。值得一提的是，在1.5 wt.% GNS复合材料中未反应的GNS形成团聚体，导致力学性能急剧下降。
