Removing Oxide Layers and Retaining Oxide‐Free Steel Surfaces by Polishing in Oxygen‐Free Atmosphere

Metal oxides pose significant challenges across numerous applications, including brazing, compound casting, and additive manufacturing. This is because these oxides form instantaneously under ambient atmosphere. The removal of metal oxides and the retention of oxide‐free surfaces have been demonstrated to have advantageous effects in many applications. A variety of methods have been shown to be effective for deoxidation, including nonthermal plasma for copper and iron, and laser treatment for aluminum. Nonetheless, while mechanical methods such as brushing, grinding, and polishing have been demonstrated to be advantageous in certain applications, they have not yet been proven to provide oxide‐free surfaces. In this study, the efficacy of wet mechanical polishing under an oxygen‐free atmosphere is reviewed as a method for oxide removal and for retaining oxide‐free surfaces on oxygen‐affine metals. The stainless steel 1.4301 is used, as the deoxidation of chromium by nonthermal plasma has not yet been demonstrated. It is found that, while the oxide layers were indeed mostly removed, the extent of removal depends heavily on the solvent used to clean the surfaces after polishing. The result can be improved by solvent degassing, but partial reoxidation of the polished surface cannot be prevented.