Abstract: Ni-based high temperature self-lubricating IS304 (IS: Induction Sintering) composites with BaF₂/CaF₂and Ag particles as lubricants were prepared by ball milling and induction sintering techniques. The microstructure of the IS304 composites is dense and the size of selflubricating particles is very fine. BaF₂/CaF₂ particlesare in dimension of about 1 μm and particles are less than 2 μm respectively,while some BaF₂/CaF₂ particles are distributed in Cr₂O₃particles. The synthesized IS304 composites exhibite high friction coefficientin the temperature range from roomtemperature to 250℃. However, thefriction coefficient dramatically decreased at 280℃ while the friction coefficient of coarsecomposites dramatically decreased at 330-350℃ in the same test condition due to the formation of self-lubricating fluoride films. The fluoride films formed on the worn surface of synthesized composites is attributed to the size refinement and appropriate distribution offluorides, which can lead toa higher temperature rise (flash temperature) at the instantaneous contactingsurface.

Key words: high temperature coating, distribution of lubricants, size-refinement