Study On The Repair Of The Surface Of Bearing Bush By Flame Spraying Tin-based Babbitt Alloy

The bearing bush is an important part of the engine,and its quality directly affects the working performance of the engine.In order to ensure the working performance of the bearing bush and improve economic efficiency,it is necessary to repair the worn surface.In this subject,flame spraying technology is used to repair the surface of tin-based Babbitt alloy composite coating on the surface of cast tin bronze ZCu Sn₅Pb₅Zn₅,which is a common material for engine bearings.First,designing the flame spraying test program of the coating,and then flaming spray the tin-based babbitt alloy composite coating with higher microhardness and self-lubricating properties on the surface of tin bronze.The coating is divided into two groups.The first group adds 3%,5%and 10%Ni_60Aalloy powder to the tin-based babbitt alloy powder to form a coating;the second group adds 3%and 5%Mo S₂to the tin-based babbitt alloy powder forms a coating,and the flame sprayed samples are tested.First,conduct a hardness test along the horizontal and vertical directions of the coating section to measure the microhardness of the coating;perform abrasion test on the coating surface to measure the friction coefficient and mass wear amount of the coating;perform microstructure analysis on the coating section,Determine the microstructure morphology;carry out phase analysis on the coating surface to determine the composition of the chemical phase in the coating.The test results show that in the tin-based babbitt alloy with 5%Ni_60Acomposite coating,the microhardness of the coating is higher;when the wear load is 50N,75N and100N,the friction coefficient and mass wear of the coating surface are relatively high.Low,the wear mechanism of the coating is abrasive wear;XRD analysis shows that the Ni Cx hard phase content in the coating is higher,which improves the microhardness of the coating,and the coating contains Si O₂,which improves the coating The abrasion resistance;SEM analysis shows that the cross-section of the coating has better compactness,and the powder is completely melted,which improves the microhardness of the coating.In the composite coating of tin-based babbitt alloy with 3%Mo S₂,the microhardness of the coating is higher;when the wear load is 50N,75N and 100N,the friction coefficient and mass wear of the coating surface are lower,and the coating The wear mechanism of the layer surface is adhesive wear.According to the XRD analysis,the coating contains Si O₂,Pb Sn O₃and Mo S₂,which improves the wear resistance of the coating.According to the SEM analysis,the coating surface is flat without defects such as pores and pits.In the repair of the bearing bush,flame spraying tin-based babbitt alloy with 5%Ni_60Aor 3%Mo S₂coating can effectively improve the wear resistance of the bearing bush and extend the service life of the bearing bush.