Microstructure and properties of KNO3- based water-soluble salt core strengthened by glass fiber

Abstract The KNO3-based water-soluble salt core was prepared using 70%KNO3-30%KCl (mole fraction) as a matrix material and glass fiber as a reinforcing material by stirring casting method. The effects of different glass fiber contents on the bending strength, impact toughness, water solubility rate and hygroscopic rate of the water-soluble salt core were compared and analyzed. The scanning electron microscopy and energy spectrometer were used to analyze the microstructure characteristics of the water-soluble salt core strengthened by glass fiber. The results show that with the increase of glass fiber content, the bending strength and impact toughness of the salt core are increased, and the water solubility rate and moisture absorption rate are gradually decreased. When the mass fraction of glass fiber is 30%, the salt core has the largest bending strength of (38.85±0.61) MPa and impact toughness with (2.13±0.1) kJ/m2, and the water solubility rate is still as high as (476.5±12.0) g/(min·m2), and the moisture