Improvement of Wear Resistance of High-Strength Brass by Friction Stir Processing

High-strength brass is commonly used to produce sliding parts; however, its wear resistance should be further improved to extend the service life and performance of machinery and equipment constructed using this material. In this study, friction stir processing (FSP), a technology based on friction stir welding, was used to improve the wear resistance of high-strength brass. Because the application of FSP requires subsequent finishing operations on the workpiece, milling and wire electrical discharge machining (WEDM) have been implemented and their effects on the surfaces modified by FSP were investigated. FSP refined the crystal grains, resulting in improved hardness from 240 to 300 HV. Sliding tests were conducted to evaluate the friction and wear properties under three conditions: without FSP, with FSP and milling, and with FSP and WEDM. After applying FSP and milling, the wear amount decreased by 15%, in other words, the wear resistance improved compared with that observed without FSP. With FSP and WEDM, the wear resistance did not improve.