铝-石墨烯复合镀层对7075铝合金硬度优化研究

Study on Hardness Optimization of 7075 Aluminum Alloywith Aluminum-graphene Composite Coating

在有机体系下制备了铝-石墨烯复合镀层,研究了7075铝合金硬度和耐磨性的优化工艺。采用正交试验研究了工艺参数对复合材料表面硬度和耐磨性的影响。采用单因素试验分析了石墨烯浓度和电流密度对硬度的影响规律。利用SEM、XRD、Raman光谱分别对复合镀层的微观形貌、相结构及石墨烯的存在进行表征分析。结果表明:各工艺参数对复合材料硬度和耐磨性的影响顺序均为石墨烯浓度>电流密度>电镀时间>搅拌速度。随着石墨烯浓度和电流密度的增大,复合材料硬度均出现先升后降的变化趋势。在优化工艺下,复合材料表面硬度较基体硬度提升了229.9%,而其摩擦系数较基体的降低了90.1%,说明了石墨烯优异的机械强度和自润滑性强化了复合材料的力学性能。

Aluminum-graphene composite coating was prepared under organic system,and the optimum process of hardness and wear resistance of 7075 aluminum alloy was studied.The effects of process parameters on the surface hardness and wear resistance of the composites were studied by orthogonal test,and the effects of graphene concentration and current density on the hardness were analyzed by single factor test.The micro-morphology,phase structure and the existence of graphene of the composite coating were characterized and analyzed by SEM,XRD and Raman spectra.The results show that the order of the effects of process parameters on the hardness and wear resistance of the composites is as follow:graphene concentration>current density>electroplating time>stirring speed.With the increase of graphene concentration and current density,the hardness of the composites increases at first and then decreases.Under the optimized process,the hardness of the composite surface is 229.9%higher than that of the matrix,while the friction coefficient is 90.1%lower than that of the matrix,indicating that the excellent mechanical strength and self-lubricity of graphene strengthen the mechanical properties of the composite.