纳米凹凸棒石对磨损表面的摩擦改性

Tribological modification of nano attapulgite powders on wear surface

将主要含有Mg、Al、O、Si等元素的凹凸棒石按质量分数0.5%添加在柴油机润滑油CD 15W/40中,配制成对比油样。分别利用X射线衍射（XRD）与透射电镜（TEM）分析凹凸棒石的物相组成及颗粒形貌,使用环块摩擦磨损试验机进行摩擦实验,借助表面轮廓仪、聚焦离子束扫描电镜（focus ion-beam scanning electron microscope,FIBSEM）、能量弥散X射线探测器（energy dispersive X-ray detector,EDX）及TEM分析试样的磨损量及磨损表面的形貌、元素和物相组成,并探讨磨损表面的摩擦改性机理。结果表明：该凹凸棒石属于一维纳米材料,分散在CD 15W/40润滑油中使摩擦副的磨损量降低约66%,磨损表面光滑;摩擦过程中,纳米凹凸棒石与摩擦副表面发生复杂的化学反应,形成一层厚度约为10~20 nm的摩擦改性层,其物相组成为晶态和非晶态的SiO2和铝硅酸盐,含有Al、Fe、Si、O、C等元素。

The attapulgite powders, which mainly contained the elements ofMg, AI, O, Si, were dispersed into the diesel engine lubricant oil CD 15W/40 with the mass fraction of 0.5 % to make a contrast oil sample. The X-ray diffraction （XRD） and transmission electron microscope （TEM） were used to investigate the phase composition and particle morphology of the experimental attapulgite powders. The tribological modification research of wear surface was examined using a block-on-ring friction-wear tester. After that, the contourgraph, focus ion-beam scanning electron microscope （FIBSEM）, energy dispersive X-ray detector （EDX） and TEM were used to analyse the wear mass loss, wear surface morphologies, elements and substance phase of the rubbed surface, respectively. Then the tribological modification mechansms of wear surface were also discussed. The results show that, the attapulgite belongs to the one dimension nano material, and it can reduce the value of wear mass loss about 2/3 of rubbing pair dispersed in lubricant oil, and the rubbed surfaces are smooth lubricated with the mineral powders. In the tribological process, a modified film with thickness about 10-20 nm forms due to complex chemical reactions at the interface of attapulgite and rubbing pair. The film composted crystalline and amorphous SiO2 and aluminosilicate salt which contains the elements of AI, Fe, Si, O, C has anti-wear property.