TRIBOLOGICAL PROPERTIES OF BRAKE FRICTION MATERIALS CONTAINING ULEXITE AND BORAX

Turkey has biggest boron reserves in the world. Although there are more than 150 boron minerals in nature, mainly economical boron minerals are borax, colemanite and ulexite. A limited number of studies investigating brake friction materials containing boron minerals are available in the literature. In this study, three brake lining samples containing borax and ulexite differing in amount (4, 8 and 12 wt.%) were produced and tested on a full scale brake dynamometer with a gray cast iron rotor disc. The brake linings were characterized by measuring their hardness and density. The weights of each specimen was taken before and after the friction test, and the specific wear rate was determined in accordance to a TSE 555 (1992) standard. The results indicated that borax and ulexite have ideal application effect in friction materials and is a kind of novel modifier for friction materials