One. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure one.one.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mostly made up of borosilicate glass, a material renowned for its small thermal growth coefficient and chemical inertness. The chemical make-up generally contains silica (SiO₂, fifty-90%), alumina (Al₂... https://www.bib.az/post/229333_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html