Influence and mechanism of borax on the physico-mechanical properties of magnesium potassium phosphate cement exposed to high temperatures

Abstract

This paper studied the effect of borax content on the physic-mechanical properties and microstructure of MKPC at high temperatures. Borax affected the performance of MKPC by changing phase composition and structure at high temperatures. Borax can react with magnesia to form Mg3B2O6 at around 800 °C. The porosity of MKPC reduced at temperatures of higher than 900 °C, mainly due to the melting of Mg3B2O6. As borax content increased from 3% to 15%, MKPC showed a denser structure and higher strength at 1100 °C. Excellent dimensional stability of MKPC at high temperatures can be obtained at low borax content.