Room and High-Temperature Wear Behaviour of Al-Based MMCs against an Automotive Brake Pad

Abstract

Article Room and High-Temperature Wear Behaviour of Al-Based MMCs against an Automotive Brake Pad Lucia Lattanzi * and Anders Eric Wollmar Jarfors Department of Materials and Manufacturing, School of Engineering, Jönköping University, Gjuterigatan 5, 55318 Jönköping, Sweden * Correspondence: lucia.lattanzi@ju.se Received: 29 November 2024; Revised: 27 December 2024; Accepted: 31 December 2024; Published: 6 January 2025 Abstract: Aluminium metal matrix composites are promising materials for automotive brake discs, and it is critical to assess their wear performance in different braking conditions. This article presents the wear behaviour of aluminium-based composites with different Al-Si matrix alloys added with nickel and copper to retain mechanical strength at high temperatures. The wear tests were conducted at room and high temperatures (250 and 400 °C) to simulate different braking conditions on a pin-on-plate tribometer. The coefficient of friction is in the range of 0.15–0.17 for all materials at room temperature. The specific wear rates of the brake pad and the disc materials indicate that material transfer occurs from the brake pad to the metal counterpart. Microscopy investigations of the wear tracks confirm the material transfer on the composites. It protects the composite surface from wear damage and maintains a stable coefficient of friction. To translate these results into real-world scenarios, the findings of this study suggest that aluminium-based metal matrix composite brake discs have a longer product lifespan compared to the grey cast iron brake discs; the brake pads for the composites would be the components to need replacement due to wear during the product life instead of the brake discs.