Effect of Braking Speed on Frictional Properties of Short Fiber C/C-SiC Brake Materials and Grey Cast Iron

• Published in: Tribology transactions 2013-07, Vol.56 (4), p.630-636
• Main Authors: Fan, Shangwu, Deng, Juanli, Xu, Xingya, Liu, Haiping, Zhang, Junzhan, Zhang, Litong, Cheng, Laifei
• Format: Article
• Language: English
• Subjects: Applied sciences; Brakes; Braking systems; Ceramic Composite; Drives; Exact sciences and technology; Friction; Mechanical engineering. Machine design; Resins; Shafts, couplings, clutches, brakes; Tribology; Velocity; Wear
• ISSN: 1040-2004; 1547-397X
• DOI: 10.1080/10402004.2013.776158

Short fiber C/C-SiC brake materials were prepared by dipping the fibers in resin, chopping, warm pressing, and pyrolyzing, followed by a liquid silicon infiltration process. The effect of braking speed (initial braking speed) on the frictional properties of a pair of short fiber C/C-SiC brake materials and grey cast iron (HT250) (C/C-SiC-HT250) was investigated. The results indicated that the average friction coefficient of the C/C-SiC-HT250 increased to the maximum value at 10 m/s and then decreased with an increase in braking speed. The wear rate of the C/C-SiC increased with increasing braking speed when it was lower than 10 m/s and decreased when it was higher than 10 m/s. The wear was the result of the brittle fracture of asperities when the braking speed was lower than 10 m/s and induced granular debris. The wear for the tough cutting by C/C-SiC asperities or hard phase when the braking speed was higher than 10 m/s and resulted in ribbon debris. When the braking speed was higher than 20 m/s, the texture of the friction surface of the HT250 changed, which would affect the tribological properties.