Using Textured-DLC Coating to Improve the Wear Resistance of Stainless Steel Plate Under Dust-Containing Lubricant Condition

Abstract

Sliding mechanical parts working under heavy loads and at high speeds in harsh environments are often subjected to sand and dust, leading to abnormal wear and seizing. Although sliding surfaces can be hardened and textured, there is a need for even higher wear and seizure resistance. We therefore did this study to confirm the trapping effect of surface texturing on dust by finding a way to visualize the dust. As a result, we confirmed that the dust became trapped in the grooves of the texture during the sliding. In addition, to produce a sliding surface having both seizure and wear resistance, we produced a surface combining a diamond-like carbon (DLC) film and surface texturing, and we evaluated its tribological characteristics. In dusty conditions, the specific wear rate was about 1/20 on surfaces where DLC film and the surface texturing were used in conjunction, and its wear resistance was higher than that of a non-treated stainless steel substrate. On the other hand, a rise in the coefficient of friction due to a rise in contact stress on the corners of the texturing grooves was confirmed. Therefore, when the tribological characteristics were evaluated by changing the radii of the groove corners and the parameters of the groove depth, the coefficient of friction was the lowest, decreasing about 50% for the test sample with a corner radius of 7.1 μm.