Tribological Characteristics of Q235 Steel Modified with Micro Arc Oxidized Coating:An Experimental Study

The surfaces of Q235 steel,a water pipe material,were modified by micro arc oxidation(MAO).The influence of the oxidation time on the microstructures and tribological behavior of MAO coatings was investigated with X-ray diffraction(XRD),scanning electron microscopy(SEM) and conventional mechanical probes.The results show that the oxidation time had a major impact.To be specific,as the oxidation time increased,the thickness,compactness,surface roughness and friction coefficient of the MAO coatings increased,the growth-rate and surface porosity decreased,accompanied by an increase of the corrosion-resistance,however,the wear-rate and wear-track depth changed in a decrease-increase-decrease mode.The friction coefficient of MAO coating was large than that of Q235 steel,and the crater-shaped pores,with a fairly big size distribution,dominated the MAO coatings.Possible mechanisms were also tentatively discussed.