WEAR AND FRICTION STUDIES ON SILICON-NITRIDE BEARING BALLS USING S-CONTAINING POTENTIAL LUBRICANT ADDITIVES

Silicon nitride bearing balls of 12.7 mm diameter were used to evaluat e the wear and friction reducing characteristics of admixtures of para ffin oil with 0.5% w/v solution of 1,5-di-p-methoxyphenyl-2,4-dithioma lonamide and 3,5-di-p-chlorophenylimino-1,2,4-dithiazolidine in a four ball test. Both the additives were found to be quite active in reduci ng wear-scar diameter and friction coefficient values and exhibited hi gher values of flash temperature parameter and load wear index. A comp arative EP activity evaluation of both the additives using silicon nit ride and alloy steel balls was undertaken to assess better applicabili ty of silicon nitride balls in a four ball test.