SiC和SiC-WC复相陶瓷高温自润滑特性及其机理  

SELF-LUBRICATION PROPERTIES AT ELEVATED TEMPERATURES AND MECHANISM OF SiC AND SiC-WC COMPOSITES

作　　者：周松青[1] 肖汉宁[1] 杨巧勤[1] 

机构地区：[1]湖南大学材料科学与工程学院,长沙410082

出　　处：《硅酸盐学报》2004年第12期1470-1475,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金上海宝钢(50174024)联合资助项目

摘　　要：研究了SiC和SiC-WC在真空中的自对偶高温摩擦性能。随着温度的升高，SiC／SiC的摩擦系数变化不大，比磨损率(自对偶体积磨损量与接触压力和摩擦路程之比)从20℃到800℃保持为4.0×10^(-8) mm^3／(N·mm)(模式Ⅰ)，从800℃到1 200℃减少(模式Ⅱ)，自对偶的高温磨损机理由轻微的粘着磨损控制，磨损由模式Ⅰ向模式Ⅱ转化，呈现出高温自润滑特性。SiC-WC／SiC-WC显示了较低的摩擦系数，直到1 200℃均不高于0.35，在1 000℃、0.4 MPa压力下自对偶的比磨损率仅为SiC／SiC的比磨损率的50％左右。在600℃SiC／SiC摩擦氧化明显，氧化物主要为无定形的SiO_2，在摩擦表面形成一层由微米或亚微米级无定形平滑薄膜层，这就是样品出现自润滑的机理。The tribological characteristics of SiC and SiC-WC self-mated couples from room temperature to 1200°C in vacuum was studied. With the increase of test temperatures there is no much changes in the friction coefficient of SiC/SiC, while the specific wear rate remains the constant of 4.0 × 10-8 mm3/(N&middotmm) from 20°C to 800°C (Mode-I), and decreases from 800°C to 1200°C (Mode-II), the specific wear rate of it is the rate of worn volume against contact load and sliding distance. Adhesive wear plays decisive role in wear mechanisms of self-mated couples. When the specific wear rate changed from Mode-I to Mode-II, the self-lubrication characteristic of SiC and its composites appear at elevated temperatures. The friction coefficient of SiC-WC/SiC-WC is not over 0.35 until 1200°C, and its specific wear rate is about 50% of that for SiC/SiC at 1000°C under contact load of 0.4 MPa. The tribo-oxidization at 600°C is obvious to form a thin glassy film of oxide particles with micrometer or submicron size. The main oxide product is amorphous SiO2. The thin film has the effects of lubrication and improving the plastic deformation of friction surface, which is the mechanism of self-lubrication characteristic of self-mated couples.

关 键 词：碳化硅 碳化钨 复相陶瓷 摩擦磨损 自润滑 摩擦氧化 塑性变形 

分 类 号：TB302.1[一般工业技术—材料科学与工程]