Hybrid Biological Fiber-Reinforced Resin-Based Friction Materials Friction and Wear Performance Test

Abstract

Friction material is essential for automotive braking system. Based on previous study of existing friction material problems, hybrid biological fiber-reinforced resin-based friction materials (HBRMs, from the reinforced fiber component of resin-based friction materials) were explored in this study. Bamboo fiber, jute fiber and wool fiber (all have length of 3-5 mm) were processed to make three types of HBRMs and considered as three factors of biological reinforced fiber in test using orthogonal experimental design. Each factor had three levels of 1%, 2% and 3% fiber mass fraction while the ratio of other raw materials remains unchanged. According to the orthogonal experimental design table, nine formulations (denoted as M1-M9) were determined to test the HBRMs. For comparison, non-bio-fiber reinforced friction material (NBM) was added in the test. The properties of the HBRMs tested included Rockwell hardness, impact strength and density. The friction and wear performance of the braking materials was examined by a speed friction tester. The results show that the friction coefficient of the HBRMs was slightly higher than that of the NBM, indicating biological fibers affected the friction coefficient. The friction coefficient of the HBRMs decreased firstly with the increase of temperature and had the lowest value when the temperature reached 300°C, and it increased then as temperature increased. During recovery process, the friction coefficient of the HBRMs firstly increased with the decrease of temperature and then decreased greatly when the temperature dropped to 100°C. The wear rates of the HBRMs increased with the increase of temperature and reached maximum value when temperature reached 200°C, then it decreased with the increase of temperature. The results of fuzzy comprehensive evaluation analysis on the friction coefficient and wear rate show that the best comprehensive properties were presented when the mass fraction of bamboo, jute and wool fiber were 3%, 3% and 1%，respectively.