Development and Evaluation of Maize Husks (Asbestos-Free) Based Brake Pad

Abstract

The development and evaluation of maize husks as asbestos-free friction material for the production of automotive brake pad was carried out in this work. Asbestos friction material that has been used for over 80 years was found to be carcinogenic in nature and has prompted several research efforts for its replacement from brake pads. Three sets of composite compositions were made using maize husks as filler material to impart friction properties with varied epoxy resin contents as the matrix that bonded the particles in the mix.  Brake pad specimens were made out of the composites and subjected to mechanical, physical and tribological analyses to ascertain their possible performance in service using standard test procedures, materials and equipment. The particulate size of the MH filler material was 300µm and epoxy resin was in slurry. The result showed that specimen composite 3 with 30% MH filler content having coefficient of friction, abrasion resistance, water absorption, oil absorption, density, hardness, tensile strength, compressive strength, and thermal conductivity of 0.37, 4.470E-6g/m, 0.725%, 0.660%, 0.852g/cm³, 99.34mPa, 14.407mPa, 6.779mPa and 0.330W/mk respectively was optimum in performance. It was observed that reducing the filler content increased hardness, wear rate, tensile strength, compressive strength and thermal conductivity of the composite brake pad, while density, coefficient of friction water and oil absorption got increased with increased MH filler content. The result when compared with those of conventional brake pad made of asbestos and other friction materials of past researches showed that MH particles are an effective replacement for asbestos in automotive brake pad manufacture. Unlike asbestos based brake pad, the composite brake pads are eco-friendly and do not have the health hazards like cancer aggravation, asbestosis, mesothelioma, lung and other ailments associated with use of asbestos bearing components.

Keywords: Brake pad; asbestos; maize husks, tribological properties.