One. Scientific Foundations of Hollow Glass Microspheres 1.one Composition and Microstructure 1.1.one Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mainly made up of borosilicate glass, a material renowned for its very low thermal expansion coefficient and chemical inertness. The chemical make-up generally involves silica (SiO₂, fifty-90%), alumina ... https://ekcochat.com/post/809413_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html