(1. 湖南科技大學(xué) 材料科學(xué)與工程學(xué)院，湘潭 411201；
2. 湖南科技大學(xué) 高溫耐磨材料及制備技術(shù)湖南省國(guó)防科技重點(diǎn)實(shí)驗(yàn)室，湘潭 411201)
摘 要: 納米ZrO2(Y2O3)強(qiáng)韌化的雙尺度Mo-12Si-8.5B復(fù)合材料具有優(yōu)異的力學(xué)性能，但在25~1000 ℃范圍處于空氣和真空下的干滑動(dòng)摩擦學(xué)性能尚不清楚。采用銷-盤式摩擦磨損試驗(yàn)，比較研究Mo-12Si-8.5B-2.5%ZrO2(Y2O3)/Si3N4配對(duì)副的干摩擦學(xué)性能。結(jié)果表明：在空氣中，隨著測(cè)試溫度的增加，摩擦因數(shù)先增加后減小，800 ℃時(shí)達(dá)到最小值(為0.28)；復(fù)合材料的磨損率在25~600 ℃時(shí)為6.02~69.4×10-6 mm3/(N·m)，800~1000 ℃的磨損率增加到8.7×10-3~95×10-3 mm3/(N·m)。在真空中，從25 ℃升高到400 ℃時(shí)，摩擦因數(shù)從0.62逐漸降低至0.49，600 ℃時(shí)急劇增加到1.04，而在800 ℃和1000 ℃時(shí)摩擦因數(shù)又分別降低到0.82和0.51，此時(shí)磨損率從常溫的8.62×10-4 mm3/(N·m)減小到1000 ℃的1.61×10-4 mm3/(N·m)。在空氣環(huán)境下，復(fù)合材料的磨損機(jī)制主要為黏著磨損，高溫時(shí)還伴隨著氧化磨損。在真空中，復(fù)合材料在低溫時(shí)的磨損機(jī)制主要為黏著磨損，高溫時(shí)磨損機(jī)制表現(xiàn)為黏著磨損、犁削磨損和輕微的氧化磨損。
關(guān)鍵字: Mo-12Si-8.5B；真空；空氣；摩擦學(xué)性能；磨損機(jī)制
（1. College of Materials Science and Technology, Hunan University of Science and Technology, Xiangtan 411201, China;
2. Hunan Provincial Key Defense Laboratory of High Temperature Wear resisting Materials and Preparation Technology, Hunan University of Science and Technology, Xiangtan 411201, China）
Abstract:A bimodal grain size Mo-12Si-8.5B composite strengthened and toughed with nano-ZrO2(Y2O3) exhibits excellent mechanical properties. However, the dry friction and wear of the composite at 25-1000 ℃ in air and vacuum are not clear. The dry tribological behaviours of the Mo-12Si-8.5B-2.5%ZrO2(Y2O3) composite against Si3N4 were comparatively investigated. The results show that the friction coefficient increases first and then decreases with the increase of the test temperature in air, and reaches the lowest value of 0.28 at 800 ℃. The wear rates of the composite are 6.02×10-6-69.4×10-6 mm3/(N·m) at 25-600 ℃, and increases to 8.7×10-3-95×10-3 mm3/(N·m) at 800-1000 ℃. In vacuum, the friction coefficient decreases from 0.62 to 0.49 when the temperature increases from 25 ℃ to 400 ℃, and then increases sharply to 1.04 at 600 ℃, then decreases again to 0.82 and 0.51 at 800 ℃ and 1000 ℃, respectively, and the wear rate decreases from 8.62×10-4 mm3/(N·m) at 25 ℃ to 1.61×10-4 mm3/(N·m) at 1000 ℃. In air, the wear mechanism of the composites is adhesive wear, and accompanies with oxidation wear at high temperature. In vacuum, the wear mechanism of the composites at low temperature is adhesive wear, while exhibits the characterizations of adhesive wear, micro-ploughing wear and slight oxidation wear at high temperature.
Key words: Mo-12Si-8.5B; vacuum; air; tribological properties; wear mechanisms
