Tribological Properties of Fiber and Particle Reinforced Hybrid Aluminum Composite

(1)采用销-盘摩擦磨损试验机研究了添加Al_2O_3纤维和Al_2O_3颗粒的ADC 12压铸铝的摩擦学性能。Al_2O_3纤维直径为4 μ m，加入量为2%~ 26%，长度为200 ~ 40 μ m。Al_2O_3颗粒的尺寸范围为0.6 - 20 μ m。在载荷为10 N、滑动速度为0.1m/s的条件下，将金属基复合材料（MMC）与氮化不锈钢（SUS 440 B）进行摩擦磨损试验，结果表明，纤维和Al_2O_3颗粒增强的铝基复合材料具有良好的抗干滑动磨损性能。在初始严重磨损时，增强体阻止了磨损裂纹扩展和塑性流动。增加纤维的体积分数可以改善稳态的轻度耐磨性，这显然是由于均匀分散的破碎纤维形成了坚硬的表面，并通过氧化接触表面来防止粘附。从t 关于我们 通过磨损率和SEM观察，将复合材料的磨损机制分为3种类型：1.以基体材料为主的低体积分数MMCf的粘着磨损; 2.高体积分数MMCf和小颗粒混杂MMC的三体磨粒磨损; 3.大颗粒混杂MMC的二体磨粒磨损。(2)采用销盘式摩擦磨损试验机，在空气和真空环境下，对SiC颗粒增强铝基复合材料与0.45%碳钢的摩擦磨损性能进行了研究。在空气中，SiC颗粒防止或减少严重磨损，但在初始阶段磨损配合面。稳态轻度磨损率略有提高，但随着颗粒体积分数的增加而增大。在真空（5 × 10 ~ 4 <-4>Pa）条件下，复合材料的磨损率远小于基体材料的磨损率，约为空气中的1/100。特别是20 μ m的MMC由于磨粒在摩擦表面间转移而不发生磨损。少

(1) Tribological properties of ADC 12 die casting aluminum with fibers of Al_2O_3, and some with and Al_2O_3 particles added were investigated in a pin-on-disk test. The Al_2O_3 fibers were 4 mu m in diameter : they were added in volume fractions from 2% to 26%.and their length ranged from 200 to 40 mu m. The particles of Al_2O_3 of ranged in sizes from 0.6 to 20 mu m. The MMC (disk test piece) were rubbed against nitrided SUS440B stainless steel (pin test piece) with a load of 10N and a sliding speed of 0.1m/s.Aluninum reinforced with fibers and particles of Al_2O_3 can improve dry sliding wear resistance. Reinforcements prevented wear crack propagation and plastic flow in the initial severe wear. Increasing volume fraction of fibers improves steady state mild wear resistance, apparently by the formation of a hard surface of uniformly dispersed crushed fibers, and by oxidation of the contact surfaces to prevent adhesion.Increasing size of particles improves the wear resistance. From t … More he wear rate and SEM observations, the wear mechanism modes of MMC are divided into three types, namely ; 1.Adhesive wear dominated by matrix material, and MMCf with low volume fraction, 2.Three body abrasive wear for MMCf with high volume fraction, and hybrid MMC with small particles, 3.Two body abrasive wear for hybrid MMC with large particle diameter.(2) SiC particle reinforced Al composites were rubbed by 0.45% carbon steel using pin-on-disk apparatus in air and vacuum environments. In air, SiC particles prevent or decrease severe wear but abrade the counterface in the initial stage. The steady state mild wear rate slightly improved by reinforcements but became larger with an increase of volume fraction of particle. In vacuum (5 x 10^<-4>Pa), the wear rate of MMC,which was about 100 times smaller than that in air, was considerably smaller than that of matrix material. Particularly, the MMC with particle of 20 mu m did not wear because the wear particles transfered between rubbing surfaces. Less