Wear behavior of high volume Al2O3-reinforced Al7075 matrix composites fabricated by semi-solid powder processing

چکیده مقاله

The aim of the present study is to fabricate high volume Al₂O₃-reinforced Al7075 matrix composite by semi-solid powder processing method as an effective method to achieve the desired wear properties. The alloy powder (20 µm) was mixed with Al₂O₃ (120 µm) for 10 min and 5 h by planetary ball mill to overcome the powders agglomeration. The wear behavior of the composites was studied using the pin-on-disk tribometer. The effects of milling time, compact pressure, and reinforcement content were investigated to enhance the wear resistance. The results of the tribotests indicated that composites with coarser reinforcing particles (lower milling time) have good wear resistance. The role of compaction pressure in highly loaded composites is remarkable. The maximum wear resistance was observed for the 50% Al₂O₃ composite. The wear resistance increased as the reinforcement volume increased before reaching a critical value. Abrasive wear is the predominant mechanism in the wear of reinforced composites containing less than the load limit. However, adhesive and laminating wear are the controlling mechanisms at overloads. The results indicate valuable information in the development of aluminum-based composites.