Enhanced Wear Resistance of Tungsten-Reinforced Brass Surface Composite Produced Through Friction Stir Processing at Varying Tool Rotational Speed

This study examines the effect of tool rotational speed on the microstructure and dry sliding wear behavior of brass–tungsten (brass/W) surface composites fabricated through friction stir processing. Microstructural analysis confirmed a uniform distribution of tungsten particles within the stir zone, with no observable clustering. Improved properties were achieved at a lower traverse speed of 40 mm/min combined with a higher rotational speed of 1168 rpm, which promoted finer grain formation (~4 µm) and better particle dispersion. An increase in rotational speed led to a corresponding rise in hardness, from 142 HV at 832 rpm to 165 HV at 1168 rpm. In terms of wear behavior, the sample processed at lower rotational speed exhibited abrasive and micro-cutting wear, whereas the sample processed at higher rotational speed predominantly showed adhesive wear.