润滑脂的溶解及铁谱分析试验研究

Experimental Study on Dissolution and Ferrographic Analysis of Lubricating Greases

针对润滑脂由于流动性差而无法直接采用铁谱技术进行磨粒分析的问题,探讨适合溶解不同润滑脂的有机溶剂。选择锂基、钙基和铝基3种目前设备润滑常用的润滑脂,通过水浴加热与超声波震荡的溶解方法,对比研究8种有机溶剂对润滑脂的溶解效果;通过摩擦试验制备带有磨粒的润滑脂试样,通过旋转式铁谱仪进行制谱试验,并结合显微镜分析谱片磨粒沉积效果。结果表明:正己烷溶液、体积分数30%二甲苯和70%正己烷混合溶液适合溶解锂基润滑脂,二甲苯和四氯乙烯适合溶解钙基润滑脂和铝基润滑脂;将润滑脂试样溶液的黏度稀释到4mm^2/s以下时,在旋转式铁谱仪上能够获得良好的制谱效果。

In view of the problem that the wear debris in lubricating grease cannot be analyzed directly by the ferrography due to the inadequate fluidity of grease,the organic solvents suitable for dissolving different greases were discussed.Three widely used greases,i.e.lithium,calcium and aluminum based greases,were selected to study the dissolution effect in eight kinds of organic solvents by using the dissolving method of water bath heating and ultrasonic oscillation.The grease samples with debris were produced by a friction test,the ferrographic experiment was performed by rotating ferrography instrument,and the debris deposition effect of the ferrogram was analyzed by the microscope.The results show that n-hexane solution and the mixed solution of 30% xylene and 70% n-hexane are suitable for dissolving lithium based grease.Xylene and tetrachloroethylene are suitable for dissolving calcium based grease and aluminum based grease.In order to obtain good debris deposition effect of the ferrograms,the viscosity of the grease solution samples should be diluted to less than 4 mm^2/s when they are tested on rotary ferrograph.