Grigoriev Sergey, Smirnov Anton, Pinargote Nestor Washington Solis, Yanushevich Oleg, Kriheli Natella, Kramar Olga, Pristinskiy Yuri, Peretyagin Pavel
Spark Plasma Sintering Research Laboratory, Department of High-Efficiency Machining Technologies, Moscow State University of Technology "STANKIN", Vadkovsky per. 1, Moscow 127055, Russia.
Scientific Department, A.I. Yevdokimov Moscow State University of Medicine and Dentistry, Moscow 127473, Russia.
Materials (Basel). 2022 Mar 25;15(7):2419. doi: 10.3390/ma15072419.
This paper presents a study of AlO-ZrO (ZTA) nanocomposites with different contents of reduced graphene oxide (rGO). The influence of the rGO content on the physico-mechanical properties of the oxide composite was revealed. Graphene oxide was obtained using a modified Hummers method. Well-dispersed ZTA-GO nanopowders were produced using the colloidal processing method. Using spark plasma sintering technology (SPS), theoretically dense composites were obtained, which also reduced GO during SPS. The microstructure, phase composition, and physico-mechanical properties of the sintered composites were studied. The sintered ZTA composite with an in situ reduced graphene content of 0.28 wt.% after the characterization showed improved mechanical properties: bending strength was 876 ± 43 MPa, fracture toughness-6.8 ± 0.3 MPa·m and hardness-17.6 ± 0.3 GPa. Microstructure studies showed a uniform zirconia distribution in the ZTA ceramics. The study of the electrical conductivity of reduced graphene oxide-containing composites showed electrical conductivity above the percolation threshold with a small content of graphene oxide (0.28 wt.%). This electrical conductivity makes it possible to produce sintered ceramics by electrical discharge machining (EDM), which significantly reduces the cost of manufacturing complex-shaped products. Besides improved mechanical properties and EDM machinability, 0.28 wt.% rGO composites demonstrated high resistance to hydrothermal degradation.
本文介绍了一种对具有不同还原氧化石墨烯（rGO）含量的AlO-ZrO（ZTA）纳米复合材料的研究。揭示了rGO含量对氧化物复合材料物理力学性能的影响。采用改进的Hummers法制备氧化石墨烯。利用胶体加工法制备了分散良好的ZTA-GO纳米粉末。使用放电等离子烧结技术（SPS）获得了理论上致密的复合材料，该复合材料在SPS过程中也使GO还原。研究了烧结复合材料的微观结构、相组成和物理力学性能。经表征后，原位还原石墨烯含量为0.28 wt.%的烧结ZTA复合材料显示出改善的力学性能：弯曲强度为876±43 MPa，断裂韧性为6.8±0.3 MPa·m，硬度为17.6±0.3 GPa。微观结构研究表明氧化锆在ZTA陶瓷中分布均匀。对含还原氧化石墨烯的复合材料的电导率研究表明，在氧化石墨烯含量较低（0.28 wt.%）时，电导率高于渗流阈值。这种电导率使得通过放电加工（EDM）生产烧结陶瓷成为可能，这显著降低了制造复杂形状产品的成本。除了改善力学性能和EDM加工性能外，0.28 wt.% rGO复合材料还表现出对水热降解的高抗性。
