Abstract:
Copper fibres are used in the composition of car and truck brake pads and they play a major role on the braking efficiency. The purpose of this study is to understand the behaviour of Cu particles in the interfacial contact area of steel against steel sliding surfaces. In this sense, pin on disc tests were carried out with the addition of particulate interfacial media to investigate the evolution of the friction coefficient with testing time. The addition of copper powders (400 μm, 20 μm and 50 nm), magnetite (50 nm) and graphite powder (25 μm) was investigated. The results were compared with the condition without any particulate addition. Scanning electron (SEM) and focused ion beam (FIB) microscopies were used to characterize the tribosurfaces of the pins and the debris on the discs to identify the composition and the microstructure of debris and tribofilm. The tribotests results showed that the Cu addition increased the friction coefficient when compared to the other conditions. The highest values for the friction coefficient were obtained for the finer Cu particle granulometry. By contrast, graphite and magnetite additions decreased the friction coefficient when compared to the condition without any addition, with the lowest friction coefficient values been obtained for condition with graphite addition.
Reference:
RODRIGUES, A.C.P.; FUKUHARA, T. Y.; ALBERTIN, E.; SINATORA, A.; AZEVEDO, C.R.F. Effect of Cu particles as an interfacial media addition on the friction coefficient and interface microstructure during (steel/steel) pin on disc tribotest. Wear, v. 330-331, p.70-78, may- jun., 2015.
Access to the summary of the article on ScienceDirect:
www.sciencedirect.com/science/article/pii/S0043164815001155
Copper fibres are used in the composition of car and truck brake pads and they play a major role on the braking efficiency. The purpose of this study is to understand the behaviour of Cu particles in the interfacial contact area of steel against steel sliding surfaces. In this sense, pin on disc tests were carried out with the addition of particulate interfacial media to investigate the evolution of the friction coefficient with testing time. The addition of copper powders (400 μm, 20 μm and 50 nm), magnetite (50 nm) and graphite powder (25 μm) was investigated. The results were compared with the condition without any particulate addition. Scanning electron (SEM) and focused ion beam (FIB) microscopies were used to characterize the tribosurfaces of the pins and the debris on the discs to identify the composition and the microstructure of debris and tribofilm. The tribotests results showed that the Cu addition increased the friction coefficient when compared to the other conditions. The highest values for the friction coefficient were obtained for the finer Cu particle granulometry. By contrast, graphite and magnetite additions decreased the friction coefficient when compared to the condition without any addition, with the lowest friction coefficient values been obtained for condition with graphite addition.
Reference:
RODRIGUES, A.C.P.; FUKUHARA, T. Y.; ALBERTIN, E.; SINATORA, A.; AZEVEDO, C.R.F. Effect of Cu particles as an interfacial media addition on the friction coefficient and interface microstructure during (steel/steel) pin on disc tribotest. Wear, v. 330-331, p.70-78, may- jun., 2015.
Access to the summary of the article on ScienceDirect:
www.sciencedirect.com/science/article/pii/S0043164815001155
