Investigation On The Characteristics Of Wear Resistance Using Silicate Particles As Additive On The Metal Friction Pairs

Self-repair technology of wear of materials is an innovation technology in the field of surface engineering. The basic components of self-repair material are hydroxyl magnesium (serpentine), activator and additive. The technology can evidently improve the physic-chemical and mechanical properties of friction pairs and reduce the wear loss by selected repairing the worn surface. It can repair the worn surface of various metals without machinery disassembly, and evidently reduce friction shock, then reduce energy consumption greatly and extend service life of the devices. In this paper, the heat treatment process, preparation, and its suspension property in lubricant of the serpentine are explored. The mechanism and suitable condition of self-repairing technology, and wear-resistant property of self-repairing material worked on non-ferric metals have been systematically studied. The main conclusions are reached as follow:1. The X-ray diffraction results of serpentine heat treated at different temperature were analyzed by Dmax-3A X-ray Diffraction apparatus. The phase transformation of serpentine can take place at 780 ℃. Its chemical transformation equation can be shown as follow:Mg₃Si₂O₅(OH)₄→Mg₂SiO₄+MgSiO₃+2H₂O2. The serpentine particulate was prepared by using QM planetary ball milling machine at different conditions. The dispersive property of the serpentine particulate in the lubricating oil was investigated using different dispersants. The optimal preparation parameters of serpentine particulate were obtained. The serpentine particulate can well suspended in the lubricant by using one percentage oil acid as it's dispersant.3. Formation process and mechanism of self-repair coating on the surface of GCrl5 balls during ball-milling, and on the surface of 45^# steel rings during the friction and wear by using the MM200 friction and wear tester were analyzed by SEM and EDXP. At the same time, this paper systemically studied the generation of the self-repairing coating at different experimental conditions. The formation ofself-repairing coating can be attributed to two mechanisms. Firstly, serpentine are trioctahedral 1:1 phyllosilicates. The sheet layers can incidental glide one another, so the, serpentine particulate can be deformed and sprawled on furrows along the metal surface. Secondly, hydroxyl silicate magnesium has many active groups. They can react with the fresh metal surface created by friction and wear. Then self-repair coating forms on the surface of the friction pairs. In addition, the optimal content of the serpentine particulates in the lubricant is 2 percentage;Addition of the graphite particulate in lubricant can effectively diminished the friction coefficient of the friction pairs. But it has no catalysis effect on the formation of the protecting coating. Along with the increase of the loads, a fully self-repair coating can be formed.4. Aluminum can be pretreated in the water containing serpentine particulates at a certain temperature. Friction and wear experiments were conducted. As a result, this process is effective in wear resistance compared with the base metal.