Wear Behavior Eolution Mechanism Of PTFE Enhanced With Glass Fiber

Stirling Engine is a kind of piston engine with external heating(or burning).It is widely applied in many fields,such as solar thermal power generation,underwater power station,power plant,heat pump air conditioning,vehicle hybrid propulsion and so on.In recent years,Stirling Engine has been developing towards high power density,which makes the wear of piston ring aggravated,and the life and reliability of the equipment are reduced.It is necessary to carry out research on the evolution mechanism of glass fiber reinforced PTFE piston ring wear according to the engine condition of Stirling,so as to provide a theoretical basis for the proposed piston ring wear control method.Aiming at the core of Stirling Engine friction-glass fiber composite piston ring PTFE nitride liner,test method for in situ observation,to explore the PTFE composite material and the transfer film changes with the wear of the trip,by observing the wear of piston ring and cylinder liner before and after the surface morphology,composition and surface micro profile measurement,reveal the evolution of the wear mechanism of glass fiber composite PTFE,the conclusions are as follows:The wear evolution of glass fiber reinforced PTFE composite and the formation of the transfer film are divided into three stages.In the running in stage,the PTFE matrix of the composite material is worn more violently on the surface of the cylinder liner,so that the glass fiber gradually exposes and bears and wears.Meanwhile,the falling PTFE matrix forms a continuous transfer thin layer on the surface of the cylinder liner.During the transition stage,the glass fiber is reunited in PTFE and iron oxide debris and re embedded into the composite surface,so the wear rate gradually decreases,while the glass fiber on the composite surface causes wear and tear on the transfer film and polished the cylinder surface.In stable stage,the wear and tear rate of glass fiber on the surface of composite materials is slightly fluctuated,and the surface of cylinder liner is formed by banded transfer film and gradually connected to the chip.In the evolution process of PTFE piston ring wear,cylinder liner surface check point near the stop point near the transfer film transfer film roughness variation is similar,correlation degree is high,and the insertion of transfer film on the variation of fractal dimension and the sliding direction of piston ring surface of the glass fiber area ratio variation is consistent.