Biodegradable cow dung for brake friction material: a preliminary investigation

The purpose of the study is to develop a biodegradable and non-asbestos/copper-free brake pad formulation. The possibility of using organic cow dung particles as an eco-friendly reinforcement in friction material for brake pads is investigated. Sodium hydroxide (NaOH) treated cow dung is Sun dried and ground to an average particle size of 200 microns. It is reinforced in epoxy resin in weight fractions of 5%, 10%, 15%, 20% and 25% along with other fillers and friction stabilizers. The composite samples are subjected to density, thermal conductivity, microhardness and tensile strength evaluation for mechanical characterization. Pin on disc testing is done to identify the coefficient of friction (CoF), wear coefficient and specific wear rate as a part of tribological characterization. The scanning electron micrographs and EDAX analysis of worn out surface is performed to study the wear mechanism. Promising results are seen with composite samples reinforced with 15% cow dung particles in terms of better microhardness, tensile strength, stable coefficient of friction and low wear. The investigation could guide industries working on brake pad materials. This could open up an era of low cost, organic and eco-friendly alternative to carcinogenic asbestos/copper in friction materials.