一种高性能烧结摩擦材料摩擦剂的选择

Selection of friction modifiers of an excellent sintered friction material

合理选择摩擦组元对改善高性能金属基烧结摩擦材料的性能至关重要 .采用粉末冶金工艺制备了以SiO2 ,SiC ,B4C等为摩擦剂的金属基烧结摩擦材料 ,研究了该摩擦组元对材料的机械性能特别是摩擦磨损性能的影响 ,探讨了其作用机理 .研究结果表明 :同时添加SiO2 ,SiC ,B4C作摩擦剂的材料比单独添加SiO2 ,SiC或SiO2 +SiC的材料综合性能优异得多 .这是由于除了SiO2 ,SiC作为摩擦组元具有一些优良性能外 ,B4C与铁在烧结温度下反应生成了一种高硬度的金属间化合物Fe2 B ,其综合作用结果使该材料的摩擦因数比其他 3种材料高出 3 0 %～ 4 0 % ,摩擦因数稳定度高出 2 0 %～ 60 % ,且磨损小 ,是一种理想的。

It is very important to select friction components for metal base sintering friction materials. Friction materials which contain SiO 2, SiC and B 4C have been fabricated by powder metallurgy technology. The effects of SiO 2, SiC and B 4C on mechanical properties, especially friction and wear characteristics have been studied. The results show that using SiO 2, SiC and B 4C together as friction modifiers of material is much better than using SiO 2, SiC respectively or SiO 2, SiC together. The reason is that reaction between B 4C and Fe takes place during sintering. A new product Fe 2B appears in matrix of the material. The material which contains this intermetallics together with SiO 2, SiC as friction modifiers has excellent properties: its friction coefficient reaches 0.33～0.37, and its stability of friction coefficient reaches about 0.85. The wear rate of both material itself and matching material is low. Therefore, this kind of metal base sintering friction material can be satisfactory for the use of brake under high and heavy load conditions.