Abstract:To prolong the effectiveness of the ballpoint pen and improve the antiwear property of the ball socket of ballpoint pen,Scanning electron microscope (SEM) and Xray photoelectron spectroscopy (XPS) were used to characterize the lubrication film on the surface of ball socket which was consist of freecutting stainless steel wire.The writing performance of the ballpoint pen was tested and compared by ballpoint pen writing lubrication tester before and after the adsorbed film on the surface was sintered under vacuum environment.The results show that there is a layer of lubrication film about 500 nm thick on the surface of ball socket of ballpoint pen tip,and the lubrication film is adsorbed on the surface of the ball socket through chemical adsorption when the cutting oil is used for processing the freecutting stainless steel metal tip.The lubrication film is mainly composed of a hydrophilic substance such as a hydrocarbonbased acid or a hydrocarbonbased alcohol.The lubrication condition between the ball and the ball socket is boundary lubrication.The lubrication film can reduce the friction and wear of the pen tip,and compared with the results without the lubrication film,the average friction coefficient of the tip is decreased by 32%,the wear rate is decreased by 77%.The mark of the refills without lubrication film on the pen tip presents regular light color and continuous decrease of ink output.When the pen tip slides for 600 m,it will be completely invalidated due to greater wear.The mark of the refills with lubrication film is full and clear,and the change in ink output is slight.The hydrophilic substance in the lubrication film can improve the wettability of the ball socket on ink,which can continuously improve the lubrication performance of pen tip and achieve longterm service for ballpoint pen.