Research On Preparation And Properties Of Wear-resistant Coating For Bush

PEEK bearings are suitable for water lubrication and self-lubrication.Compared with engineering plastics such as PTFE,they have better load-bearing performance,and heat resistance is better than Babbitt alloy.Domestic and foreign scholars and the industry have done a lot of research on the modification of PEEK materials.The research work on material friction reduction,wear resistance,material strength and toughness is relatively rich.However,as a bearing material,the bonding strength between PEEK and metal is still insufficient.Under extreme conditions of heavy load,impact or high operating temperature,the current level still cannot guarantee the reliability of the bearing.Therefore,in order to solve this problem,the subject optimized the steel / PEEK sintering process parameters,and on this basis,emphatically studied the influence of the surface treatment of the metal substrate on the steel / PEEK interface bonding strength,and combined with the finite element analysis to explore the influence mechanism.Research on the steel/PEEK hot pressing process shows that temperature has a greater influence on the quality of the steel / PEEK interface bond.Below 370 ?,PEEK has poor fluidity and poor interface wettability,and there are large cracks at the interface.As the temperature increases,with the fluidity of PEEK increasing,the quality of interface bonding is improved and the interface is tightly bonded.There are almost no defects such as cracks and pores.The heat preservation time also has a great influence.At the heat preservation time of0.5 h,the steel / PEEK interface has obvious unbonded gaps,and the PEEK layer is delaminated.So the PEEK thermal conductivity is poor.The insufficient heat preservation time causes the surface to plasticize,but the interior is not ideal.Flow state,so the combination is poor.With the increase of holding time,PEEK is fully melted,and the interface wetting state is improved,so the combination of steel / PEEK is better.When the hot pressing pressure is 0 MPa,there are cracks and holes in the steel / PEEK interface.As the pressure gradually increases,the interface state is improved.The surface treatment results of the metal substrate show that sandblasting can increase the contact area between PEEK and the metal substrate,and at the same time form some special structures to promote the mechanical locking between the two,so it is conducive to the steel /PEEK interface combination.As the particle size of sandblasting increases,the bonding strength of the steel / PEEK interface increases.The blasting treatment further improves the surface condition,corrodes on the basis of sandblasting,eliminates the sharp structures and residual sand particles caused by sandblasting,further increases the roughness and reduces the stress concentration caused by the sharp structures,thus further enhancing the interface bonding strength.The finite element analysis results show that the steel / PEEK interface with general structure is interface fracture,and as the surface roughness increases,the interface bonding strength also gradually increases;the interface with a special structure with a certain angle is mixed fracture,and the mechanical Locking can greatly improve the steel / PEEK interface bonding strength.The experimental results show that the surface-treated steel / PEEK tensile fracture surface is a mixed fracture(result of special structural action).There are both fractures at the interface and PEEK,and the interface fracture area is large.