Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs

Abstract

To study the influence of nano-additives on the friction-wear characteristics of friction materials, the nano-sized silicon carbide particles which have excellent chemical and physical properties are considered to add in composite to form the modified friction material. The influence of the silicon carbide nanoparticles (SCN) on the friction-wear characteristics of copper-based friction materials (CBFM) is investigated via the SAE#2 (made in Hangzhou, China) clutch bench test with the applied pressure, rotating speed, and automatic transmission fluid (ATF) temperature taken into account. Moreover, the variations of friction torque and temperature are considered to evaluate the friction performance, and the variable coefficient is employed to describe the friction stability. The wear characteristics of friction materials are investigated by the disc changes in thickness and micro-morphology. The results show that the CBFM with SCN can provide a higher friction torque, which increased by 30% to 50% compared with CBFM. The variable coefficient of CBFM with SCN changes from 674 to 52 with the rotating speed raised from 600 rpm to 3000 rpm, which shows that the friction stability is relatively worse. Furthermore, the micromorphology shows that the CBFM with SCN has lower porosity and surface roughness, which increases the microscopic contact area and the coefficient of friction (COF). Simultaneously, the reduction in porosity also leads to a decrease in the cooling quality, bringing about a rapid temperature rise. Thus, the wear amount of CBFM with SCN increases significantly, especially for the friction disc in the axial middle position.

Holistic Measurement of the Friction Behavior of Wet Clutches

“…Nevertheless, numerous publications focus on the investigation of dynamic friction behavior, which can be characterized in different, application-oriented operational modes like brake shift operation (e.g., [20]), steady slip (e.g., [21]), or transient slip (e.g., [22]). The choice of a suitable test procedure should follow the needs of the intended operation mode for the genuine clutch system.…”

Effect of Wet Granulation on Tribological Behaviors of Cu-Based Friction Materials

“…With the development of nanomaterials, researchers began to investigate how nanomaterials regulate CBFMs’ tribological behaviors. Nano-sized silicon carbide, with excellent chemical and physical properties, was added to CBFMs, and COF was successfully increased by 30~50%; however, it had poor stability to braking speed [ 11 ]. Different from nano-sized silicon carbide, Nano-AlN could provide a more stable COF and better wear resistance which were attributed to the fact that the Nano-AlN can refine the matrix grain of CBFMs [ 12 ].…”