Effect of hardness and morphology of potassium titanate on frictional wear characteristics of brake pads

We investigated the effects of the properties of potassium titanate (PT), a raw material used in automobile brake pads, on the resulting frictional characteristics. Potassium hexatitanate, K2Ti6O13 (PT6), with a non-fibrous shape, was synthesised by acid leaching and subsequent thermal treatment of potassium tetratitanate, K2Ti4O9 (PT4), with the layered crystal structure. Comparing frictional characteristics, the brake pads including the largest sized PT6 (b, mean size ~72 μm, 980 Hv) with high mechanical hardness exhibits much higher coefficient of friction (COF) values and wear amounts of both the friction material and counter disc than the others. Our PT6 particles (a, mean size ~15 μm, hardness ~674 Hv) with the higher mechanical hardness than commercial PT6 (c, mean size ~24 μm, hardness ~310 Hv), show almost the same COF value and pad wear amount as PT6, c, despite reduced mean particle size. On the other hand, wear amounts and roughness of counter disc were found to be increased by ~30% for PT6, a...