Synergy between surface mechanochemistry and subsurface dissolution on wear of soda lime silica glass in basic solution

The polishing of oxide glass in aqueous solution is sensitive to not only the mechanical conditions applied by abrasives but also the chemistry of solution. This study elucidates the synergistic interactions of mechanical and chemical effects—especially, the synergetic effects of surface mechanochemical wear and subsurface dissolution are studied by measuring the material removal rate of soda lime silica (SLS) glass upon rubbing with a Pyrex glass ball in noncorrosive (neutral pH) in corrosive solutions (pH 10 and 13 NaOH) as a function of sliding speed. Based on the synergetic model of surface wear and subsurface dissolution, it is found that the mechanochemical surface reaction dominates the wear behavior of SLS glass in neutral and pH 10 solution conditions; the wear of SLS glass in pH 10 is enhanced, compared to the neutral pH case, due to the presence of OH^- ions at the sliding interface. In the case of pH 13, the dissolution of the densified subsurface region, which is formed due to interfacial friction during the surface wear, becomes significant, further enhancing the material removal yield. The finding provides an insight for designing an efficient polishing process in manufacturing of oxide glass materials with a good surface finish.