Preparation of Controlled Microporous High Speed Steel and its Composite Self-Lubrication Materials

High speed steel (HSS) with controlled micropores was prepared via vacuum sintering process, using the mixture of stearic acid, TiH2 and CaCO3 compound as pore-forming agent. A self-made vacuum high pressure infiltration furnace was used to infiltrate the preform with 60Pb40Sn40-15Ag-0.5RE solid lubricants to create self-lubrication composite where both solid lubricant phase and matrix phase were interpenetrating throughout the microstructure. Effects of pore-forming agent on micropore structure and porosity of the prepared microporous HSS preforms were investigated. The scanning electron microscope (SEM) observation was applied to the test samples and it revealed that the micropores of the microporous materials exhibited a uniform distribution and the apertures were of almost same size in principle. The friction and wear behaviors of the composite sliding against ZrO2 ceramic under a load of 50 N at 600 °C were investigated using a pin-on-disk wear tester and the results showed that this kind composite possessed excellent high temperature self-lubrication properties.