2019, 21 (4):
In the 1950’s, complex calcium lubricating grease had been widely used. However, due to the hardening problem in the process of storage and use, the production of complex calcium lubricating grease decreases year by year. Domestic and foreign researchers have done a lot of work on its hardening problem, and it has been found that boric acid and phosphoric acid can effectively improve the hardening problem. In this paper, the water absorption test of several calcium salts was carried out, and it was found that calcium 12-hydroxystearate did not absorb water, and calcium acetate, calcium phosphate and calcium borate had different degrees of water absorption. Calcium acetate has the highest water absorption rate, and calcium phosphate and calcium borate have comparable water absorption rates. Using molecular simulation technology, it is found that in the complex calcium grease system, calcium phosphate and calcium borate prefers to combine with water, which inhibits the water absorption of calcium acetate and makes the hardening problem better.