Surface feature variations observed in 52100 steel sliding against a thin boron carbide coating

Boron carbide (B4C) is well known for its high hardness and wear resistance and has been used as a wear-resistant coating. If one of a pair of contact surfaces is coated by B4C, it may polish its mating surface and act as a run-in coating. Developing such run-in coatings demands a thorough understanding of the mating surface evolution in wear. This paper reports a study on the characteristics of the surface feature variations of 52100 steel balls run against B4C coated disks. The contact conditions, asperity contact temperature, pressure and deformation are analyzed. Changes in the surface statistical properties, asperity height autocorrelations and power density spectra are monitored for the 52100 steel as the sliding distance increases. The results indicate that under the conditions used in this research, the B4C coating can accomplish polishing in a sliding distance of less than 2m. Based on these observations we suggest a new paradigm for an ideal run-in coating.