1. Scientific Foundations Of Hollow Glass Microspheres one.1 Composition and Microstructure one.1.1 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 makeup typically features silica (SiO₂, 50-90%), alumina (Al₂O₃, https://followingbook.com/post/560846_metallic-boride-powders-are-very-unique-but-functional-new-ceramic-materials-the.html