Mechanical Properties of Annealed Soda Lime Silica Glass with Various Potassium Salt by Ion Exchange

Abstract

This work studied the effect of ion exchange parameters on the glass properties. The regular soda lime silica glass was annealed at 600 ºC for 16 hours, followed by the chemical treatment process. The chemical treatment was carried out using different types of potassium salts at two different temperatures. Different ion exchange media in salt paste were prepared using KNO₃, KCl, and K₂SO₄ and heat treated at 425 ºC and 465 ºC for 4 hours. The mechanical properties of the glass before and after ion exchange treatment were analyzed using the 3-point bending and Vickers hardness method. The results show the highest flexural strength was obtained after the annealed glass was treated with KCl for 4 hours at 425 ºC. Meanwhile, treatment with KNO₃ at 425 ºC resulted in the highest Vickers hardness strength and glass fracture toughness compared to samples treated with other potassium salts. From both characterization techniques, the K₂SO₄ salt medium showed the lowest flexural strength, hardness, and fracture toughness values. Additionally, ion exchange treatment at 465 ºC reduced the glass's mechanical properties as higher treatment temperatures lead to surface structure stress relaxation.