Tribological performances of ceramic oxide nanoparticle additives in sodium borate melt under steel/steel sliding contacts at high temperatures

The tribological and anti-oxidation performances of Sodium Borate melt with added ceramic oxide nanoadditives (SiO 2 , TiO 2 , Al 2 O 3 , ZrO 2 , CaCO 3 ) have been studied on stainless steel at 930 °C. Characterizations of wear surfaces in terms of morphology and interfacial chemistry have also been conducted to address the lubrication and antioxidation mechanisms. SiO 2 nanoparticle was found to deliver the best anti-oxidation and lubrication performances outperforming other nanoparticles due to its synergistic reactions with sodium borate melt. Intriguingly, SiO 2 nanoparticle also inhibits the corrosion attack of sodium toward the oxide/steel surfaces and the boriding effect. Meanwhile, other nanoparticles can only either improve the lubricity or anti-oxidation of sodium borate but fail to limit the corrosion of the oxide scale from sodium. All data generated or analyzed during this study are included in this published article (and its supplementary information files ). • Different nanoparticles were tested under sodium borate melt lubrication at 930 °C. • SiO 2 nanoparticles outperform others in improving the performance of sodium borate. • Addition of SiO 2 nanoparticles boosts the anti-oxidation of sodium borate by 80%. • No corrosion attack of sodium to the oxides with the addition of SiO 2 nanoparticles. • TiO 2 and ZrO 2 nanoparticles improve the lubrication but not the anti-oxidation.