Experimental investigation on microstructure characteristics and mechanical behavior of a developed bi-treated soda-lime glass

Abstract

This work aims at developing an ideal glass that can harness the properties of both chemically tempered glass (CTG) and fully tempered glass (FTG) by combining chemical and thermal tempering process. Glass samples with dimension 120×50×4mm were prepared and first immersed in potassium nitrate salt (KNO3) inside a salt bath and subjected to heating at temperatures of 450°C and 500°C with immersion time of 4h and 5h for each temperature respectively in a muffle furnace to produce CTGs. The CTGs were then later subjected to thermal tempering at a fixed temperature of 450°C to produced bi-treated glasses (BTGs). Scanning electron microscope (SEM) was used to investigate the microstructure of the glasses while tests such as hardness, flexural strength and impact strength were used to evaluate the mechanical behavior of all the glasses. The results showed that the BTGs displayed high flexural strength which increases as temperature and time increases over the CTGs and FTG respectively while the hardness values of the BTGs also improved considerably as temperature and time increases over the CTGs and FTG respectively. However, the BTGs displayed decrease in impact strength as compared to CTGs and FTG. In term of microstructure, the BTGs displayed a compacted nodule-like structure evenly distributed throughout the glass matrix which accounts for the good mechanical behavior of the developed BTGs.