Experimental Investigation of Friction and Wear in Automotive Brake Pads: The Role of Load and Speed

Abstract This study examines the frictional and abrasive wear characteristics of a semi-metallic brake pad composite under different applied loads, sliding velocities, and rotating speeds. The brake pad, consisting of 13 components including SiC, MgO, and 3-mm aramid fibers, was produced by powder metallurgy and assessed according to SAE J661 standard standards. The results indicated that the coefficient of friction (COF) rose from 0.697 at 5 N to 0.795 at 30 N, signifying enhanced interfacial resistance attributable to surface compaction and tribo-film stabilization. The specific wear rate increased with load, from 0.405 g/N at 5 N to 1.065 g/N at 30 N, indicating a compromise between friction and wear resistance. The sliding velocity demonstrated a dual effect: the (COF) rose from 0.663 at 0.4 m/s to 0.797 at 0.8 m/s, while the wear rate climbed from 0.47 g·s/m to 1.02 g·s/m, representing a 116% escalation. Increasing the RPM from 100 to 1000 resulted in a significant 64.5% reduction in the (COF), decreasing from 0.44 to 0.156, attributable to heat softening and surface deterioration. SEM research indicated a change in wear mechanisms from abrasive at 200 RPM to oxidative at 400 RPM, and severe adhesive wear at 800 RPM. These findings underscore the necessity of improving operational circumstances to reconcile friction performance with material durability in high-speed braking systems.