Excessive Brake Drum Wear (EBDW) and Its Prevention

Excessive brake drum wear (EBDW) occurs under severe braking conditions, leaves “peaks” and “valleys” on the drum surface, accumulates metallic particles on the lining surface, and makes significant vibration and noise. It has been generally believed EBDW is caused by wear between the metallic particles on the lining surfaces and the brake drum, but it is remained unclear of the origins of the particles. A study was carried out to investigate the metallurgical properties and formation mechanisms of metallic particles contributed to EBDW. Metallurgical evidences showed that the EBDW particles were nucleated on the lining surface via a complicated metallurgical process under high temperatures during braking. After nucleation, the particles grow in size through adhesive wear. Measures were proposed to mitigate the formation of the particles so that EBDW could be prevented or reduced.