Surface Hardness and Abrasion Threshold of Chemically Strengthened Soda-Lime Silicate Glasses After Steam Processing

Chemical strengthening by diffusive ion exchange (IOX) is a common method to improve the mechanical performance of glass products. However, the process of ion-stuffing is often associated with an increase of surface hardness and a decrease of the resistance to abrasive wear during scratching, even when the thickness of the exchanged layer is low. Autoclave steam-treatment presents a way to compensate the enhanced surface brittleness accompanying IOX. It causes a notable shift in the load threshold for microabrasion to more abrasion-resistant glasses. Subject to the specific processing parameters, the softening effect is constrained to a surface layer of less than 500 nm in thickness; therefore, the overall compressive stress profile is not affected and the advantages of IOX strengthening are retained. In turn, ion-stuffing by IOX counteracts severe autoclave corrosion of soda-lime silicate glasses, making them suitable for a combination of both processes.