One. Scientific Foundations of Hollow Glass Microspheres 1.one Composition and Microstructure one.1.one Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mostly made up of borosilicate glass, a fabric renowned for its low thermal growth coefficient and chemical inertness. The chemical make-up normally consists of silica (SiO₂, 50-ninety%), alumina (Al₂O₃, https://www.dostally.com/post/345007_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html