Study On Preparation And Performance Of Self-lubricating Coating By ESD Based On Non-conductive Ceramics

The technique that makes aluminum trioxide ceramics conductive was studied,copper coating was prepared on ceramic substrates by electro-less plating so that the ceramic substrate's electrical conductivity was improved.Cu/Cu-MoS₂ coating were prepared by electric spark deposition process on the surface of ceramic substrate's copper coating.The connection of key preparation parameters on the thickness,roughness of surface,micro-structure,friction&wear properties of the self-lubricating coating was studied.Use the overlay gauge to measure the coatings'thickness.The result showed that the thickness of coating is getting larger at first and then decreased with the increase in electrode rotation speed,discharge power and discharge frequency.When the electrode rotation speed is at 5^thh grade,the discharge power is 40?F,the discharge frequency is 70Hz,the coating's thickness is best of all.The coating's surface roughness was measured by the roughness meter,the result showed that the coating's roughness is decreased at the beginning and then increased with the increase of electrode rotation speed,discharge power and discharge frequency.When the electrode rotation speed is at 5^thh grade,the discharge power is 40?F,the discharge frequency is 50Hz,the coating's surface roughness is best of all.Observe the coatings'surface micro-structure with SEM,it can be seen that the coating's surface is uneven.The coating's surface micro-structure shows typical ESD characteristics.There exist some air holes and cracks on coating's partial area.When the electrode rotation speed is at 5^thh grade,the discharge power is 40?F,the discharge frequency is 50Hz,the coating's surface is most smooth.Use the HSR-2M high speed reciprocating friction and wear testing machine to conduct the experiment of friction and wear.The result showed that wear resistance of self-lubricating coating is more than 2.2 times that of Al₃O₂ ceramics substrate.With the increase in electrode rotation speed,discharge power and discharge frequency,the wear volume and friction coefficient of the coating decreased at first and then increased.When the electrode rotation speed is at5^thh grade,the discharge power is 40?F,the discharge frequency is 50Hz,the wear volume and friction coefficient of the coating are the minimum,at the same time,the friction properties of the coating is best.It is known that shear slip occurred on the surface of self-lubricating coating and coating's wear mechanism has obvious characteristics adhesive wear.