Nur Hidayah Yaakob^1,a, Norfadhilah Ibrahim^1,b,*, Julie Juliewatty Mohamed^1,c and Muhammad Azwadi Sulaiman^1,d  

¹Faculty of Bioengineering and Technology, Universiti Malaysia Kelantan, Jeli Campus, 17600 Jeli, Kelantan, Malaysia

^aj22d007f@siswa.umk.edu.my, ^bnfadhilah@umk.edu.my, ^cjuliewatty.m@umk.edu.my, ^dazwadi@umk.edu.my 

Abstract. Ion exchange is a chemical process used to improve the properties of alkali-contained glass. The exchanging of large K⁺ with the smaller Na⁺ introduced the surface compressive stress. The presence of compressive stress reduces the tendency of glass to fail by reducing surface flaws. Hence, this study was conducted to find the suitable type of potassium compound and temperature for ion exchange that can improve the mechanical properties of the glass. In this study, soda lime silica glass was annealed at 600 ºC for 16 hours before proceeding with chemical treatment process. The chemical treatment was carried out using different types of potassium salts at two different temperatures. Different ion exchange media in form of salt paste were prepared by using KNO₃, KCl and K₂SO₄, and 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. From the experiment, 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 compared to samples treated with other potassium salts. From both characterization techniques, the K₂SO₄ salt medium showed the lowest mechanical strength value. Additionally, ion exchange treatment at 465 ºC reduced the mechanical properties as higher treatment temperatures lead to structure viscoelastic relaxation.  

Keywords: Ion exchange, soda lime silica, potassium, mechanical, compressive stress