不同碳原子数及羟基数醇中Ti3SiC2/Si3N4摩擦副的摩擦学性能

Tribological Property of Ti3SiC2/Si3N4 Friction Pair in Alcohols with Different Carbon and Hydroxyl Numbers

Ti3SiC2和Si3N4等陶瓷材料是一种潜在的生物燃料发动机及功能性运动部件材料,为研究其在醇类生物燃料及润滑剂中的摩擦学性能,利用往复式摩擦试验机研究Ti3SiC2/Si3N4摩擦副在不同碳原子数直链醇(乙醇、丁醇、辛醇和十二醇)和不同羟基数醇(乙二醇和丙三醇)液体介质中的摩擦学性能。结果表明:Ti3SiC2/Si3N4在醇介质中的摩擦因数随碳原子数和羟基数的增加而减小,总体平均摩擦因数在0.06~0.11范围内变化,但丁醇中摩擦因数最高,为0.25;Ti3SiC2/Si3N4配副的磨损率均随碳原子数和羟基数的增加而减小,Ti3SiC2的磨损率在4.48×10^-7~9.33×10^-9 mm^3/(N·m)范围内变化,Si3N4的磨损率在4.05×10^-6~2.91×10^-7 mm^3/(N·m)之间变化,其中在辛醇和十二醇中几乎没有磨损。研究表明:在醇介质中Ti3SiC2/Si3N4摩擦副的摩擦状态属于边界润滑状态,摩擦界面微凸体和磨屑的犁沟效应是造成高摩擦的主要原因;摩擦化学反应是Ti3SiC2/Si3N4在醇介质中的摩擦行为的一个特点,摩擦化学磨损和磨粒磨损是材料磨损的主要机制;链长越长、羟基越多,醇的黏度越大,承载能力越强,犁沟效应和磨粒磨损降低,摩擦因数和磨损率也降低。

Ceramic materials such as Ti3SiC2 and Si3N4 are potential materials for biofuel engines and functional moving parts.In order to study their tribological properties in alcohol biofuels and lubricants,the reciprocating friction tester was used to study the tribological properties of Ti3SiC2/Si3N4 tribo-pair in linear alcohols with different carbon numbers(ethanol,butanol,octanol and dodecanol)and different hydroxy alcohols(ethylene glycol and glycerol).The results show that the friction coefficient of Ti3SiC2/Si3N4 tribo-pair in alcohols is decreased as the number of carbon atoms and the number of hydroxyl groups increase,and the average friction coefficient varies from 0.06 to 0.11,but the friction coefficient in butanol is the highest(0.25).The wear rate of Ti3SiC2/Si3N4 tribo-pair in alcohols is decreased as the number of carbon atoms and the number of hydroxyl group increase.The wear rate of Ti3SiC2 varies from 4.48×10^-7 to 9.33×10^-9 mm^3/(N·m),and the wear rate of Si3N4 varies from 4.05×10^-6 to 2.91×10^-7 mm^3/(N·m).Among them,Si3N4 has little wear in octanol and dodecanol.The friction state of Ti3SiC2/Si3N4 tribo-pair in alcohols is in the boundary lubrication regime,and the furrow effect of micro-convex and wear debris between the friction interfaces is the main cause of high friction coefficient.Tribochemical reaction is a characteristic of the friction behavior of Ti3SiC2/Si3N4 in alcohols.Tribochemical wear and abrasive wear are the main mechanisms of material wear.The longer the chain length and the more hydroxyl groups,the higher the viscosity of the alcohol,the greater the bearing capacity,so the furrow effect and the wear of the abrasive grains are reduced,and the friction coefficient and wear rate are also reduced.