Properties of foamed glass upon addition of nanocarbon and sintering temperatures

Abstract

As a blowing agent, 2–10 wt% of nanocarbon (NC) was added 10 µm glass powder (CaO, MgO, Al2O3, SO3, 83 wt%-SiO2) and sintered at 700–900°C to fabricate foamed glasses with closed pores that were 62–2200 µm. Optical microscopy was used to examine the microstructure and pore size. Compressive strength tester and a heat flow meter were used to examine the changes in mechanical strength and thermal conductivity. The microstructure examination results showed that was performed at 700°C, 297.9–351.3 µm pores were fabricated, and the porosity was 57–63 % in the sample that contained 6–10 wt% NC. At sintering temperatures above 750°C, the pore size increased as the NC content and the sintering temperature increased. The thermal conductivity was maintained at less than 0.28 W/m‧K. Therefore, it is possible to use 6–8 wt% NC as a blowing agent in glass material to produce foamed glass that has closed pores of approximately 500 µm with better or equivalent compressive strength and thermal conductivity properties than existing 1000 µm grade foamed glass, despite being sintered at a temperature of approximately 100°C lower.

Keywords

• foamed glass
• closed pore
• sintering temperature
• pore size
• compressive strength