Balaji, M. and Kalaichelvan, K., "Influence of Aramid, Cellulose and Acrylic Fibers in NAO Brake Pad - Effect on Thermal Stability and Frictional Characteristics," SAE Technical Paper 2013-26-0081, 2013, doi:10.4271/2013-26-0081.
Non-Asbestos organic composite friction materials are increasingly used in automotive brake disc pad applications. The present paper deals with the role of various organic fibers namely Aramid, Acrylic fibers and the Cellulose fibers on the fade and recovery behavior of friction composites. The combination of various organic fibers percentage for thermal behavior is considered using Thermo Gravimetric Analysis (TGA). The temperature raise during brake application will be between 150°C to 400°C and this zone of temperature is very critical to determine the fade characteristics during friction testing. Hence, three different friction composites are developed with same formulation varying only the percentage of Aramid, Cellulose and Acrylic fibers within the formulation. The formulations containing 10%, 12.5% and 15% of these fibers are developed as brake pads and designated as NA01, NA02 and NA03 respectively. Thermal analysis has been conducted using TGA. The tribological properties are tested using friction coefficient test rig following SAE J 661a standard. The fade μ and recovery μ % are significantly influenced by the amount and type of fiber combinations. It is observed that, increase in amount of fiber % has significant effect on fade μ %. Also, more number of primary plateaus are observed with higher fiber content showing its good fade and wear resistance. Worn surface analysis by SEM has proved to be useful in understanding the wear behavior of the composites.