Experimental Study On The Mechanism And Properties Of Self-Repair On The Worn Metal Surface Of Serpentine Powder

One of the major reasons resulting in the failure of mechanical parts should belong to wear. How to on-line self-repair the early wear and prolong lifetime of machines and equipments has attracted much attention. Recently, a technology for in-situ dynamic self-repair on the micro-damage metal surface (also called technology for on-line self-repair on worn material) is very fascinating, which is in-situ dynamic repair the micro-damage on metal surface in order to prevent or restrain the failure on mechanical parts. Therefore, the research on the technology mentioned above is beneficial to its application.In this thesis, using a MMU-5G type end-face friction and wear tester as auto-restoration tester and a self-made serpentine powder, which is mainly constituted of magnesium silicate hydroxide, as the self-repairing additive, the effect of the self-repairing additive on the friction and wear behavior of 45# steel friction pair under different experimental conditions were investigated. The morphologies and chemical compositions of worn 45# steel surfaces were analyzed by means of SEM and EDS. In addition, the self-repairing mechanism for the serpentine powder has been investigated primarily.The experimental results have shown that, a about 6μm thick, smooth and dense self-repairing coating is observed on the worn surface in the condition of 200 N load or 5% additive concentration at room temperature. At higher temperatures, shorter time is needed for the formation of the self-repairing coating. Furthermore, the addition of serpentine powder can improve the high temperature friction and wear performance for the 45# steel friction pair, and the temperature rise is beneficial to this improvement.