Effect of sintering temperatures and foaming agent content to the physical and structural properties of wollastonite based foam glass-ceramics

Abstract

This study aims to fabricate low-cost foam glass-ceramic using soda-lime-silica (SLS) glass waste and clamshells (CS) as foaming agent in content between 1 and 12 wt.% by conventional powder processing method. The samples were undergoing sintering process between 700 and 1000?C with holding time of 30 minutes and characterized according to the physical and structural properties. Samples containing 3 wt.% CS treated at 800?C show the greatest size of porosity. As the sintering temperature increased, the samples tend to become less dense. However, for the samples sintered at 900 and 1000?C, the trend of the density changes because of the excess CO2 gases generated during the heat treatment process promotes an increase in internal pressure, which results in the rupture of the pore walls. For linear expansion, for samples with a sintering temperature of 800?C and higher, the increment of the temperature will lead to the decrement of linear expansion (%). As the sintering temperature increases from 700 to 800?C, the water absorption (%) increases. However, the percentage of water absorption decreases with the further increment of sintering temperature. The XRD characterization showed the formation of wollastonite phase (CaSiO3) and further revealed the formation of greater peaks of CaSiO3 at the higher sintering temperatures. The results of compressive mechanical strength between 0.15 and 1.50 MPa indicate that the obtained glass-ceramic foams have potential for building material applications.

Additive Manufacturing of Glass-Ceramic Parts from Recycled Glass Using a Novel Selective Powder Deposition Process

“…When varying the sintering temperatures (T sint ), no clear linear dependency with distortions was found, which contradicted what D. Yang et al [35] concluded using borosilicate glass and temperatures between 640 • C and 680 • C. However, when compared with research results using recycled soda-lime-silica glass from windshields, as presented in Gualberto et al [36], or with recycled sauce bottles in Jaafar et al [40], similarities could be found. Namely, the specimens sintered at 800 • C had the smallest shrinkage.…”

“…Gualberto et al found that increasing the sintering temperature up to 800 • C would lower the density of the specimens since the crystallization would occur before the sintering was complete, causing a rapid increase in viscosity and successively less dense materials [36]. Jaafar et al [40] state that a further increase in the sintering temperature to values above 800 • C, together with secondary effects, would lower the viscosity of the glass and provoke the increase in density, which can result in greater shrinkage. However, these comparisons are limited in the sense that the materials used, processing techniques, and sintering conditions are different from the ones used in this study.…”

“…In a preliminary study, batches of thin cuboid specimens were produced in the parallelepiped crucibles and were sintered at temperatures of 750, 800, and 850 • C, with a sintering hold time of 1 h. The Coniex glass microspheres' sintering temperature was estimated at 730 • C by the material provider. Nevertheless, the work by Jaafar et al [40], which treated a similar type of soda-lime-silica glass with sintering temperatures between 700 and 1000 • C, could be consulted for alternatives.…”

Synthesis and sintering impact on the properties of willemite based glass-ceramics using rice husk waste as silica source

“…The work done by Anuar et al has highlighted the effect of sintering temperature on the structural and optical properties of ZnO-CHA [21]. The solid-state sintering process has considerably provided an alternative route not only due to its cost efficiency and simplicity in preparing the precursors, but also offers a significant improvement in physical, mechanical, and optical properties by merely adjusting the sintering environment [22]. Though sintering time does not play an essential role as sintering temperature, yet it can provide significant clarification through the studied properties.…”

Effect of sintering time on microstructure and electrical properties of varistor ceramics ZnO-CoO-SLS glass

“…Soda lime silica (SLS) glass is an abundant waste material due the cost effective for producing highly density sintered ceramics. SLS glass contains majority of 70 wt% of silicon dioxide (SiO 2 ) and minority of other compounds such as 13 wt% of sodium oxide (Na 2 O) and 11 wt% of calcium oxide (CaO) [10][11]. The addition of this source of silica in metal oxide varistor (MOV) is able to improve nonlinear coefficient of the varistor, electrical and thermal stability [12].…”