石墨粒径对聚酰亚胺摩擦性能的影响

Effect of Particle Size of Graphite on Tribological Performance of Polyimide

选用了10、20、30、40、50μm 5种粒径的天然鳞片石墨(NG)作为添加剂,通过热压成型工艺制备了聚酰亚胺(PI)/NG复合材料,对其动态热力学性能、摩擦性能及断面、磨痕形貌进行测试与表征。结果表明,NG能够提高PI的储能模量及损耗模量,但是NG的粒径对其影响较小;随着NG粒径的降低,PI/NG复合材料的摩擦因数(f)和磨损率(ω)依次减小,添加粒径10μm的NG之后,PI/NG复合材料的f为0.088 2,ω为6.19×10^(-7)mm^3/N·m,并且具备比纯PI更平滑的磨损面,以及更连续致密的转移膜。

Five types of natural flake graphite(NG)with particle sizes of 10,20,30,40 and 50μm were used to prepare polyimide(PI)/NG composites via a hotpressing technology,and the dynamic thermomechanical properties,tribological performance and morphologies of fracture and worn surfaces were investigated.The results indicated that the storage modulus and loss modulus of PI were enhanced with the addition of NG,and however,they were seldom affected by the particle size of NG.Moreover,the coefficient of friction and wear rate of PI/NG composites continuously decreased with a decrease in particle size.The PI/NG composites achieved a coefficient of friction of 0.0882 and a wear rate of 6.19×10-7mm3/N·m when NG with a particle size of 10μm was added.In addition,the PI/NG composites exhibited a smoother worn surface than pure PI,in which a more continuous and compact transfer film was obtained.