Research On Anti-scuffing Performance Of Circular Micro-texture Surface On Cylinder Liner

The friction loss between cylinder liner and piston ring group is more than 40%of the mechanical loss of diesel engine,and its friction and wear properties have important influence on the energy saving and consumption of diesel engine.With the pressure of the ship's diesel engine bursting to reach 20MPa,the lubrication state of the cylinder liner and piston ring friction interface is harsh,which leads to the increase of the friction power consumption of the cylinder liner and piston ring,and the increased chance of failure.Micro-texture is independent of staggered arrangement with a range of micro-structure of surface through the cylinder liner surface machining micro-texture morphology,which can enhance the effect of hydrodynamic pressure,store grinding grain,which can be used to improve the friction and wear properties of cylinder liner and piston ring.In this paper,based on the matching pair of boron phosphorus alloy cast iron cylinder liner and chrome based ceramic composite piston ring,the electro-chemical machining(ECM)system is designed and the parameters of ECM are optimized,besides,the circular micro-textures were machined on the surface of cylinder liner.On the piston ring reciprocating liner test rig,by designing the anti-scuffing tests,the influence on the anti-scuffing properties of different parameters of micro-textures on the cylinder liner is studied.By analyzing the results of simulation of ANSYS and the test,the wear law of the micro-textures is obtained,the conclusions are as followed:(1)With the increasing of the velocity of the cathode,both the depth and the diameter of the circular micro-texture are increased and then decreased;with the increasing of electrolyte flow,the depth of the micro-textures first increased and then decreased,and the diameter decreased;with the increasing of power voltage,both the depth and diameter of micro-textures increased;with the increasing of electrolysis time,the depth and diameter of micro-textures increased.When the cathode velocity is 10mm/s,the electrolyte flow rate is 45ml/s,the power supply voltage is 10V and the electrolysis time is 60s,the geometrical morphology of the micro-textures are the best.(2)The results of anti-scuffing tests show that,with the increasing of diameter of circular micro-textures,the friction coefficient decreased first and then increased,the anti-scuffing time increased first and then decreased;with the increasing of the area ratio of micro-textures,the friction coefficient decreased first and then increased,the anti-scuffing time increased first and then decreased;with the arrangement of micro-textures deviate from disjoint to intersect,the friction coefficient decreased first and then increased,the anti-scuffing time increased first and then decreased.In the end,when the diameter is 1000?m,the area ratio is 22%,the arrangement is intersect 2,the micro-textures on the cylinder liner have the smallest friction coefficient,when the diameter is 800?m,the area ratio is 22%,the arrangement is intersect 1,the micro-textures on the cylinder liner have the longest anti-scuffing time.(3)By analysing the surface morphology on the cylinder liner and the simulation of ANSYS,the region of the periphery of the circular micro-textures and the middle region of adjacent circular micro-textures are the most stressed areas;under the action of reciprocating friction,the cylinder liner has a plastic deformation and cracks falling off,the detached matrix is crushed to the micro-texture pits with the relative motion of the friction pairs.