自修复添加剂的热处理及其分散性研究

Research on Heat Treatment of the Self-repairing Additive and its Dispersibility

采用差热-热重分析仪(DTA-TG)研究了自修复添加剂-蛇纹石粉体的热处理过程;采用X射线衍射仪(XRD)和红外光谱分析仪研究了其相变情况;采用不同的分散剂对蛇纹石粉体和热处理后粉体进行表面修饰,使用红外光谱仪分析了它们的分散特性;采用MM-200摩擦磨损试验机研究了表面修饰后粉体的自修复特性。结果显示:蛇纹石粉体在795℃发生相变生成非晶态的顽火辉石和镁橄榄石并且在890℃发生晶化反应;油酸与蛇纹石粉体表面的羟基发生酯化反应;钛酸酯偶联剂NXT-105与热处理前后粉体不但发生了物理吸附,并且与粉体表面的羟基发生了化学反应,因此,添加剂在润滑油中具有更好的分散性;钛酸酯偶联剂修饰后的粉体,不管是热处理前还是热处理后都能在摩擦磨损过程中在磨损金属表面生成自修复膜。

The heat-treatment process of the self-repair additive-serpentine particulates was investigated by using differential thermal analyzer（DTA-TG）. Phase transformation was studied by using X-ray diffraction apparatus（XRD） and infrared spectrometric analyzer（IR）. The serpentine and heat-treated particulates were surface modificated by using different dispersants, and their dispersive properties were analyesd by using infrared spectrometric analyzer. The self-repairing performance of the modificated particulates were investigated by using MM-200 friction and wear tester. The experimemtal results show that phase transformation from serpentine to amorphous protobastite and forsterite can take place at temperature of 795 ℃ and crystallization at temperature of 890 ℃. Esterification can take place on the surface of the additive between the oleic and the hydroxyl group of the serpentine particulates. The titanate coupling agent NXT-105 is physically adsorbed on the surface of serpentine and heat treated particulates, and chemical reaction happens between the coupling agent and the hydroxyl group of the serpentine surface. Therefore, the additive possesses the better dispersive property in the lubricant oil. Both of the serpentine and heattreated particulates modificated by the tianate coupling agent can form the protective coating on the surface of the worn metals during friction and wear.