Development and experimental characterization of aluminum oxide/epoxy composite for light duty brake pad application

In this work, asbestos-free brake pad composite has been developed using aluminum oxide (Al₂O₃), calcium carbonate (CaCO₃), graphite, and epoxy resin constituent materials. Twenty-seven specimens were fabricated using hot compression moulding following a Taguchi orthogonal array design. The composite properties were optimized using grey relation analysis (GRA) and response surface methodology (RSM) by considering curing temperature and time as processing parameters. The optimal formulations of 37% Al₂O₃, 25.2% CaCO₃, 26.8% epoxy, and 11% graphite cured at 148.7 °C for 6 h achieved compressive strength of 156.77 MPa, hardness of 128.2 HB, wear rate of 3.74 mg/m, thermal conductivity of 1.18 W/m·K, water absorption of 0.64%, and oil absorption of 0.33%. These values exceeded the commercial asbestos-based brake pad performance by 42.5% of compressive strength, 26.9% of hardness, 118.7% of thermal conductivity, and 28.9% of water resistance. The developed composite shows significant improvement for environmental friendly and high-performance applications compared to the asbestos-based brake pads.