石墨烯增强AZ91镁基复合材料的力学性能

摘要

The AZ9 1 Mg alloy based composite powder and materials were prepared with graphene oxide and graphene nanosheet as strengthening phase respectively and the interface reaction mechanism of graphene oxide with AZ9 1 Mg alloy was analyzed.The mechanical properties of the composites were tested and the tensile fracture surfaces were observed.The results show that the yield strength,elongation and microhardness of the composite with graphene oxide as strengthening phase reached 224.85 MPa,8.15% and 70.14 HV,which were improved by 39.7%,35.4% and 31.8% respectively comparing to those of AZ91 Mg alloy and also much higher than those of the composite with graphene nanosheet as strengthening phase.The graphene oxide was easy to disperse uniformly with the AZ9 1 Mg alloy powder due to its oxygen groups;the interface bonding between graphene and Mg alloy matrix can be strengthened by MgO produced by the reaction between the Mg alloy and the oxygen groups,resulting in the improvement of mechanical properties of the composite.%分别以质量分数为0．1％的氧化石墨烯和石墨烯纳米片为增强相制备了AZ91镁基复合粉和复合材料,分析了氧化石墨烯与AZ91镁合金的界面反应机理；测试了复合材料的力学性能并观察了拉伸断口形貌.结果表明：以氧化石墨烯为增强相复合材料的屈服强度、伸长率和显微硬度分别为224．85 MPa,8．15％和70．14 HV,与基体镁合金的相比分别提高了39．7％,35．4％和31．8％,高于以石墨烯纳米片为增强相复合材料的；氧化石墨烯因带有含氧官能团极易与镁合金粉混合均匀,且两者反应生成的MgO有利于提高石墨烯与镁合金基体的界面结合强度,从而提高复合材料的力学性能.