Mo_5Si_3-Al_2O_3复合材料的微观结构与摩擦磨损性能

Microstructure and tribological properties of Mo_5Si_3-Al_2O_3 composite

采用机械化学还原法结合热压烧结制备Mo_5Si_3-Al_2O_3复合材料,采用XRD、SEM等对复合材料的相组成、微观结构及磨损机理进行分析。结果表明:复合材料主要物相为Mo_5Si_3、Al_2O_3和Mo_3Si,其组织均匀细小,晶粒尺寸在1~5μm之间。Mo_5Si_3-Al_2O_3复合材料具有优异的抗摩擦磨损性能。随载荷增加,其摩擦因数和磨损率降低。载荷为10 N时,其摩擦因数和磨损率分别为0.176和6.23×10^(–6) mm^3/(N·m)。与对磨件GCr15钢球相比,其磨损率降低近1个数量级。Mo_5Si_3-Al_2O_3复合材料主要的磨损机理为氧化磨损和从低载荷下的粘着-剥落磨损过渡到高载荷下的磨粒磨损。

Mo5Si3-Al2O3 composites were prepared by mechanical alloying and hot pressing sintering. The phase composition, microstructure and tribological properties of the composites were characterized by XRD, SEM and EDS. The results show that the composites are mainly composed of Mo5Si3,Al2O3 and M03Si phases. The microstructure of the Mo5Si3-Al2O3 composites are fine and uniform. Grain size of Mo5Si3-Al2O3 composites are in the range of 1-5 μm. MosSi3-A1203 composites have a good friction and wear resistance. The friction coefficient and specific wear rates of Mo5Si3-Al2O3 composites decrease with an increasing load. At 10 N loads, the friction coefficient and specific wear rates of Mo5Si3-Al2O3 composites are 0.176 and 6.23 × 10-6 mm3/（N.m）, respectively, Compared with the GCrl 5 steel ball, the specific wear rates of Mo5Si3-Al2O3 composites are decreased by one order of magnitude. The dominant wear mechanism of the composites is a transition from adhesive, delamination to abrasive and tribo-oxidation wear.