目的 研究羟基硅酸镁粉体表面改性及作为润滑油添加剂的摩擦学性能，提高羟基硅酸镁粉体在设备磨损表面的成膜性能，减少磨损，延长使用寿命。方法 采用同步热分析仪（SDT Q600），分析羟基硅酸镁粉体的相变过程。采用不同的表面改性剂对羟基硅酸镁进行改性，采用MG-2000型高速高温摩擦磨损试验机，研究不同添加量和热处理温度对羟基硅酸镁摩擦性能的影响。结果 羟基硅酸镁在常温到500 ℃之间，脱失吸附水；500~800 ℃之间，脱去层间水和结构水，生成新的物相镁橄榄石；800~860 ℃之间，晶体结构发生重组；860~1100 ℃之间，发生镁橄榄石-顽辉石物相转变。经过油酸表面改性后，羟基硅酸镁粉体表面引入了有机长链，表面改性剂改性效果为：油酸>司盘80>硬脂酸>吐温80>KH270>KH560。粉体质量分数为10%时，短时间内易于达到磨损-自修复动态平衡，具有良好的抗磨减摩效果。经过200、400 ℃热处理的粉体具有较高的活性、分散性能和成膜性能。结论 油酸能有效改善羟基硅酸镁粉体在润滑油中的分散性能，200、400 ℃热处理能有效提高羟基硅酸镁粉体在润滑油中的分散性能和摩擦过程中的成膜性能。

The work aims to study the surface modification and friction properties of magnesium silicate hydroxide powder as the lubricant additive, so as to improve the film forming performance of magnesium silicate hydroxide powder on the worn surface of equipment, reduce the wear and prolong the service life. The phase transformation process of magnesium silicate hydroxide powder was analyzed by SDT Q600. The magnesium silicate hydroxide powder was modified by different surface modifiers. The effect of different concentration and heat treatment temperature on friction and wear properties of magnesium silicate hydroxide was studied by MG-2000 high speed and high temperature friction and wear tester. Magnesium silicate hydroxide desorbed the adsorbed water from room temperature to 500 ℃, desorbed interlayer water and structural water from 500~800 ℃ and then formed new phase forsterite. Crystal structure was reconstructed between 800~860 ℃, and forsterite- diopside phase transition occurred between 860~1100 ℃. After surface modification with oleic acid, long organic chains were introduced into the surface of magnesium silicate hydroxide powder. The modification effect of surface modifiers was: oleic acid>Sipan 80>stearic acid>Tween 80>KH270>KH560. The dynamic balance of wear and self-repair could be easily achieved in a short time when the powder mass fraction was 10%, and good anti-wear and anti-friction effect could be achieved. Activity, dispersibility and film-forming properties could be effectively improved after heat treatment at 200 ℃ and 400 ℃. Oleic acid can effectively improve the dispersibility of magnesium silicate hydroxide powder in lubricating oil. Heat treatment at 200 ℃ and 400 ℃ can effectively improve the dispersibility and film-forming properties of magnesium silicate hydroxide powder in lubricating oil.