二氧化硅对玻璃在水润滑时的摩擦性能的影响

INFLUENCE OF SiO_2 NO THE FRICTION PROPERTY OF GLASS UNDER THE THE LUBRICATION OF WATERR

用栓－盘摩擦试验机，测定了石英玻璃和３种硅酸盐玻璃在大气及水中的摩擦性能，考察了试样中ＳｉＯ＿２含量，润滑介质及表面处理对其的影响。结果表明，试样中的ＳｉＯ＿２含量越高，其在水中的减摩作用越好；且这种减摩作用只在介质为水时突出，而在乙醇和液体石蜡与苯的混合溶液中却不明显。ＳｉＯ＿２在水中的减摩作用是通过其表面与水之间的相互作用而实现的。用Ｆｏｕｒｉｅｒ变换红外光谱（ＦＴＩＲ）测定了ＳｉＯ＿２粉末吸附水的行为，并在此基础上提出了ＳｉＯ＿２的减摩机理，认为水分子与ＳｉＯ＿２表面生成Ｓｉ一ＯＨ，并形成牢固附着的水分子膜是减摩的主要原因。

The friction properties of quartz glass and three types of silicate glass containing different con-tents of SiO_2 in atmosphere and in water, and the effects of lubricating medium and surface treatment on fric-tion of the specimens were evaluated using a pin on disk friction tester.It was found that the specimens withalarger content of SiO_2 have a lower friction coefficient under the lubrication of water, whereas have no sucheffect under the lubrication of ethanol or the mixed liquid of paraffin and benzene. FTIR analyses indicate thatSi-OH bond can be detected on the surface of SiO_2 powder.Considering the fact that the friction reducing ca-pability of hydrophobic treated quartz glass disappeared in water, the friction reducing mechanism of SiO_2 inwater was proposed. The Si-OH bond leads to the formation of a water film firnmly absorbed on the surfaceof SiO_2 , and this is beneficial for the friction reduction.