液晶润滑碳化硅/聚酰亚胺配副体系摩擦性能初探

Preliminary Study on Friction Properties of SiC/PI System Using Liquid Crystals as Lubricant

为探究液晶作为润滑剂对碳化硅/聚酰亚胺配副体系的润滑效果以及影响系统减摩性能的因素,分别选用单分子液晶4-氰基-4′-戊基联苯(5CB)和质量分数90%5CB-10%4′-氰基-(1,1′-联苯)-4-基4-乙基环己烷-1-羧酸酯(2CEPPN)混合液晶作为润滑剂,使用UMT-3微摩擦试验机对碳化硅/聚酰亚胺配副体系进行摩擦学性能测试。试验结果表明:单分子液晶和混合液晶作为润滑剂,对碳化硅/聚酰亚胺配副体系都具有较好的减摩效果,甚至可以达到超滑状态,其中混合液晶比单分子液晶具有更好的减摩效果;混合液晶在低载荷及较高转速下可以获得良好的减摩效果,并且能使碳化硅/聚酰亚胺配副体系在较长时间里实现超滑行为。

In order to explore the lubricating effect of liquid crystal as lubricant on the silicon carbide/polyimide(SiC/PI)rubbing pair system and the factors affecting the friction reduction performance of the system,monomolecular liquid crystal 4-cyano-4′-n-pentylbiphenyl(5CB)and mixed liquid crystal of 90%5CB and 10%4′-cyano-[1,1′-biphenyl]-4-yl 4-ethylcyclohexane-1-carboxylate(2CEPPN)were selected as lubricants respectively,and the tribological performances of the system were investigated by UMT-3 micro-friction tester.The results show that both the monomolecular liquid crystal and mixed liquid crystal have better friction reduction effects as lubricant on SiC/PI rubbing pair,and can even reach the superlubricity state.The mixed liquid crystal has better friction reduction effect than the monomolecular liquid crystal,it can achieve good friction reduction effects at low loads and high speeds,and can enable SiC/PI rubbing pair to achieve superlubricity for a long time.