Journal of Engineering Tribology, 2014, 228(5): 511-520.

Shicheng Qi, Zhezhen Fu, Rongping Yun, V Matejka, Shengling Jiang, Xiaoa Zhang, Yafei Lu*.

Abstract
The paper addresses utilization of 0–14.6 vol.% alkaline-treated walnut shell powders (WSPs) as a functional filler in the proposed eco-friendly brake friction materials. Five non-a**estos friction material samples containing WSP and jute fibers from biomass as biodegradable components were prepared, also including several from natural resources, such as wollastonite, basalt fibers, zircon, barite, and vermiculite. The friction-wear properties of the prepared composites were tested by using Chase friction performance testing device. Furthermore, an extension evaluation method was introduced to rank the composites based on their overall friction-wear characteristics. The coefficient of friction (COF) and wear rate of the samples could be effectively improved, especially for the sample with a WSP content 45.6 vol.%. With confirmation of the ****ysis and characterization results, chars were very possibly formed by the degradation of organic ingredients, such as WSP and jute fibers, which played a key role in affecting the friction performance of the friction composites.