The Study Of Heat-driven Process Of Sweating Smiulation In High Temperature Based On Pore Structure Characteristics

In this paper, the porous and self-lubricating sintered material could be obtained by infiltrating solid lubricants to the micro-pore matrix under the high-temperature. When two objects mutually contact and have a relative movement, the friction heat and other actions could be produced in the surfaces, these actions will drive the lubricants which are in the holes to the surfaces and form a layer of lubricating film with compensation role. Based on the structural characteristics of self-lubricating sintered materials, a finite element analysis model is set up, By using of "Birth and Death of Elements" method, the dynamic output process for the solid lubricants stored in the pores of high-temperature self-lubricating materials is studied, and the coupling effect of friction heat and thermal stress in driving out the lubricant is researched. The role of pore structure parameters which affected on the lubricant volume emanated from a pore has been studied, and the pore structure of the high-temperature self-lubricating material has been optimized design. The results of this study will help to explore the storage depth of lubricants in the pores and its self-lubricating life for high-temperature self-lubricating materials. The main conclusions of the study are the following:(1) By the coupling effect of friction heat and thermal stress, the deformation of pore wall has a role of driving lubricants out of the friction surface from storage pores. The deformation driving role of pore wall to the lubricants is gradually increasing before the largest deformation eventually appears in the middle position of a pore wall.(2) When the lubricant height is less than a half of the pore's height, extruding and driving role on the lubricant will gradually reduce due to the deformation.(3) When the height of the pore is certain, the deformation of the pore wall is gradually increased with the pore diameter increasing,the driving role for lubricants is increasing.(4) When the pore's height is more than four times of its diameter, the lubricant volume emanated from a pore is showed in a stable state, otherwise, the lubricant volume is in an unstable state, and shows a clear trend of decreasing.(5) When the pore's diameters of the self-lubricating materials are considerable differences, the pore wall deformation of the larger diameter promote the role of driving lubricant, and on the smaller diameter pore wall, the deformation hinders lubricants out.(6) When the pore's diameter of self-lubricating materials is certain, adding some lager diameter pores, these pores will increase the original pore volume of lubricant precipitation in the later period of material life, and the utilization of self-lubricating materials is increased.