石墨烯-铝基复合材料的制备及其性能研究

Study on Preparation and Properties of Graphene Reinforced Aluminum Matrix Composites

采用静电自组装法将氧化石墨烯(GO)分散在铝粉中,通过放电等离子烧结(SPS)制备了石墨烯铝基复合材料。采用改进的Hummers方法制备带负电荷的GO片,并用十六烷基三甲基溴化铵(CTAB)处理铝粉以获得表面正电荷。由静电自组装获得的氧化石墨烯-铝粉(GO-Al粉),实现氧化石墨烯在铝粉上的均匀吸附。SPS制备石墨烯铝基复合材料(Gr-Al)的快速烧结过程能够还原氧化石墨烯,同时减少有害碳化物的形成。使用拉曼光谱(Raman)、红外光谱(FT-IR)、透射电镜(TEM)和扫描电镜(SEM)对复合材料进行了相关测试,同时研究了Gr-Al复合材料的硬度和导热性能。结果表明,GO片均匀吸附在CTAB包覆的Al粉表面,实现了石墨烯在Al基体中的均匀分散。与铝基体材料相比较,0.2wt%石墨烯铝基复合材料的显微硬度和导热系数均明显提高,显微硬度(45.7 HV)提高41%,导热系数(203 W/(m·K))提高65%。

The graphene oxide(GO)was dispersed on the aluminum powders by electrostatic self-assembly method,and graphene aluminum matrix composites were prepared by spark plasma sintering(SPS).The modified Hummers method was used to prepare negatively charged GO flakes,and aluminum powders were treated by cetyltrimethylammonium bromide(CTAB)to obtain a positive surface charge.Graphene oxide-aluminum powders(GO-Al powders)were obtained by electrostatic self-assembly,and uniform adsorption of graphene oxide on the aluminum powders was realized.Finally,graphene oxide was reduced during SPS process to obtain a graphene aluminum-based composite(Gr-Al),and the rapid sintering SPS process helpe to reduced the formation of harmful carbides.The properties and compositions of Gr-Al were determined by Raman spectroscopy(Raman),infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Moreover,the hardness and thermal conductivity of Gr-Al composites were studied.The results show that GO flakes are uniformly adsorbed on the surface of the Al powders,and graphene sheets are uniformly dispersed in the Al matrix.Compared with the samples of pure aluminum,the microhardness and thermal conductivity of Gr-Al(0.2wt%)are significantly improved,the microhardness(45.7 HV)is increased by 41%,and the thermal conductivity(203 W/(m·K))is increased by 65%.