Preparation Of Hydroxyl Magnesium Silicate And Its Tribological Properties

Through the in-situ self-repair, the tribological properties of the frictional surface can be improved and the service life of mechanical components can be extended. As the main kind of the self-repair materials, serpentine mineral particles as lubricating oil additive can improve the lubrication properties of base oil and reduce friction and wear. But the powder itself has many inherent defects, such as impurities, difficult for purifying and grinding, and so on. In the article, magnesium hydrosilicate (MHS) powders were artificially synthesized. In addition, we also synthesized another kind of similar powder doped with nickle. The phase composition, morphology and surface structure of the synthesized powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Meanwhile, tribological properties of the powders were investigated through friction and wear experiments.Under the condition of pH=13,200℃, a series of MHS powders were synthesized through hydro-thermal reaction with MgO and SiO2as raw materials and with kettle of hydro-thermal reaction as device. XRD result showed all the diffraction peaks were MHS, without any other impurity peaks. SEM result revealed that with the increase of time, structure characteristics of hydroxyl magnesium silicate changed from lamellar structure into column structure gradually, but the profile of the column structure was not so clear. Among all the powders, the powder of12hours as lubricant additives had best antiwear properties and could reduce the worn surface. Besides, the concentration of the additives affected tribological results, and the optimum concentration was1%.In this research, MHS doped with nickle was synthesized also. It was shown that the addition of Ni2+did not affect the phase of the product, and crystalline structure of the product was restrained with the rising of Ni/Mg ratio. When the ratio of Ni/Mg was2%under the condition of12hours, the powder showed a good performance of anti-wear, but could not form a complete repair film as the powder without Ni2+. We can conclude that the addition of Ni2+in this way can not improve the tribological performance of MHS.