The size effect of zircon particles on the friction characteristics of brake lining materials

This work investigated the effect of zircon particle size on the friction characteristics of brake lining materials. Four different sizes of commercially used zircon particles (nominally 1 μm, 6 μm, 75 μm, and 150 μm in diameter) were used to produce non-steel type lining materials. We focused on the level of the friction coefficient, the oscillation of friction force, and wear resistance of the linings and gray iron counter disks were investigated with respect to the zircon size by using a pad-on-disk type friction tester. Results showed that the size of the zircon particles played a significant role in the formation of friction film, which was closely related to the friction performance. The lining material with coarse zircon particles generated a stable friction film on the lining surface, which provided excellent friction stability with less lining wear. On the other hand, the lining with fine zircon particles produced transient friction films, causing excessive lining wear and poor friction stability. Contrary to the lining wear, excessive disk wear was observed when the lining contained coarse zircon particles.