One. Scientific Foundations of Hollow Glass Microspheres 1.one Composition and Microstructure one.1.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are largely made up of borosilicate glass, a material renowned for its small thermal expansion coefficient and chemical inertness. The chemical make-up usually includes silica (SiO₂, 50-ninety%), alumina (Al... https://vherso.com/post/570520_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html