A brief overview of bulk metallic glasses

The discovery of bulk metallic glasses (BMGs) has stimulated widespread research enthusiasm because of their technological promise for practical applications and scientific importance in understanding glass formation and glass phenomena. Arising from their disordered atomic structure and unique glass-to-supercooled liquid transition, BMGs represent a new class of structural and functional materials with extraordinary properties including extreme strength at low temperature and high flexibility at high temperature, along with a number of superior chemical and physical properties. This article covers the general properties of BMGs based on a review of the historical milestones in metallic glass research, and recent progress on several fundamental issues in the development of a comprehensive understanding of the strength, ductility and glass-forming ability of BMGs and, more importantly, the correlation of these parameters with atomic structure, focusing on the outstanding questions and critical issues that appear to warrant future research. Recent advances in the applications of BMGs in microelectromechanical systems (MEMS), biomedicine and nanotechnology are also reviewed.