One. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure one.one.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mainly made up of borosilicate glass, a cloth renowned for its lower thermal expansion coefficient and chemical inertness. The chemical make-up usually features silica (SiO₂, 50-90%), alumina (Al₂O₃, t... https://vherso.com/post/570520_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html