One. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure one.1.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are largely made up of borosilicate glass, a fabric renowned for its small thermal growth coefficient and chemical inertness. The chemical make-up normally consists of silica (SiO₂, 50-ninety%), alumina (Al₂O₃, https://www.vevioz.com/post/1845440_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html