Metallofizika i Noveishie Tekhnologii, cilt.39, sa.11, ss.1511-1523, 2017 (SCI-Expanded)
The use of various materials in brake pad compositions is widely studied. In this study, the borax powders or the copper or bronze fibres are added in nonasbestos organic brake pad composition to examine the effects of type and quantity of additive on the friction and wear characteristics of brake pads. Firstly, three different specimen groups are developed by powder metallurgy method, which contain various amounts (1.5, 3, 4.5 and 6% weight) of borax powder, copper fibre, and bronze fibre. The mixtures are blended with an industrial- type mixer, pressed by hydraulic press, and then they are postsintered at 185° C for 24 hours. The friction-wear tests of specimens are performed by means of the Chase Machine according to the SAE-661 test standard, and then friction surfaces of the specimens are analysed with a scanning electron microscope. Hardness tests are performed according to the Brinell Scale test method. Test results show that, while addition of different amounts of borax powder enhances the wear resistance of brake pads, addition of copper and bronze fibres increases recovery, normal and hot friction coefficients' values with increasing amount of metallic fibre.