Researches Of Influence Of Self-Repairing Additive On Performance Of Friction Wear Of Pairs Containing Cast Iron

The development of tribology has expand the antifriction and antiwear of the researches on friction and wear into the self-repairing of worn surface, even zero wear, among them, repairing the early worn surface on-line has become the hotpot of the tribology researches.Today, in the increasing urgent demands of energy-saving and consumption-decreasing, it is of important academic and practical significance.For the past few years, the researches on self-repairing additive chiefly focused on frictional pairs of steel. Previous studies have shown that self-repairing coating can be generated on the worn surface of 45steel on-line, which reduces wear of metal materials and increases the service life.Cast iron is widely used in machine building industry as a important engineering material, in casting alloy, the output of cast iron is about 75 to 80 percent.If cast iron shows good friction and wear characteristic under self-rpairing additive, its application in industry will be further increased, and greatly reduce manufacturing cost. So, carrying out a research on friction and wear characteristics of pairs containing cast iron in self-repairing additive is of important practical significance.The research of influence of self-repairing additive on friction and wear characteristics of friction pairs with cast iron was chosen as a subject in this paper. MMU-5G end-face friction and wear testing machine was used as testing platform, experimental samples were designed independently which were convenient for being lubricated, hydroxy silicate powder were prepared by ourselves as self-repairing additive.On this condition, large numbers of experiment on friction and wear characteristics of friction pairs containing cast iron such as 45steel/cast iron,cast iron/45steel and cast iron/cast iron pairs were carried out, the influence on the friction and wear characteristics of friction pairs containing cast iron of concentration of self-repairing additive, wear time, the load on the friction pairs and the relative sliding speed of the pairs were studied systemically.The feature of worn surfaces and sections were observed by means of scanning electron microscopy, component of worn surfaces and sections were analyzed by means of energy disperse spectroscopy, the behavior of friction and wear of pairs containing cast iron in self-repairing additive have been known, and the mechanism of self-repairing additive are discussed.The results indicates that various working conditions parameters have a remarkable influence on friction and wear characteristics of friction pairs containing cast iron.When concentration of self-repairing additives, wear time, the load on the friction pairs and the relative sliding speed of the pairs are suitable,cast iron and the pairs containing cast iron have shown good performance of friction and wear.In the whole process,the frictional coefficient of pairs containing cast iron had decreased obviously comparing with ones in no additive,the weight losses of cast iron had reduced obviously from beginning to end, self-repairing additive has remarkable effect on antifriction and wearing of cast iron.The experimental results shows, self-repairing reaction can be caused on the frictional surface of 45steel and self-repair coatings generated while working conditions parameters suitable,the self-repairing coating has failed to be generated on the frictional surface of cast iron because of its metallographical structure and mechanical character.The research results of this paper have an important reference value for the further study on the friction and wear characteristic and probability of generating self-repair coatings of the cast iron lubricated in self-repairing additive, and also provide experimental reference for the application of additive on the friction pairs with cast iron.