脉冲磁场下制备的TiB_2增强ZL203复合材料的磨损行为

Wear Behavior of In-situ TiB_2/ZL_20_3 Composites Treated by Pulsed Magnetic Field Processing

采用混合盐反应法制备了原位TiB2颗粒增强ZL203复合材料,在制备过程中施加脉冲磁场处理以提高复合材料的耐磨性能。研究了不同载荷条件下材料的干摩擦磨损行为。结果表明,原位TiB2颗粒的引入显著细化了复合材料的凝固组织,施加脉冲磁场处理后复合材料的组织得到了进一步细化;与基体合金相比,原位TiB2颗粒的引入使得复合材料的耐磨性显著提高。而施加脉冲磁场处理后复合材料的耐磨性得到进一步提升,发生严重粘着磨损的临界载荷由80N提升到100N。磨损表面分析表明,基体合金的磨损机制为严重粘着磨损和剥层磨损共同作用,未施加脉冲磁场处理的复合材料的磨损为以磨粒磨损为主和轻微的粘着磨损,施加脉冲磁场处理后的复合材料主要为磨粒磨损。

In-situ TiB2 particles reinforced ZL203 alloy composites were fabricated successfully by the reaction of halide salts with aluminum melt. During fabrication process, pulsed magnetic field （PMF） was employed to improve the wear resistant properties of the composites. The dry sliding wear behavior of the matrix alloy and the composites under various loads were examined. The results show that, with the addition of TiBz particles, the solidification structure of the composites is refined apparently, and it is further refined by imposing PMF in the fabrication process. The wear resistance of the composites is sig- nificantly superior to that of the matrix alloy. And the wear resistance of composites under a heavy load is further improved by imposing PMF in the fabrication process. By comparison with the composites fab- ricated without imposing PMF, the critical transition load from mild wear to severe wear is increased from 80 N to 100 N. The analysis of worn-out surfaces indicates that the wear mechanism of the matrix alloy is characterized by the co-action of severe adhesive wear and delamination wear, and it mainly ex- hibits abrasive wear with slight adhesive wear in the composites without PMF, and abrasive wear is dominant in the composites with PMF treatment.