Crystallization of phosphate glasses

• Grant number: 06/00493-3
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): August 01, 2006
• Effective date (End): December 31, 2007
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Edgar Dutra Zanotto
• Grantee: Luciana Ghussn
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Iron phosphate glasses with varied compositions present diversified applications, being able to be used as, for example, bioabsorbable fibers for orthopedic applications, staple fibers for reinforcement of concrete and way of immobilization of high-level radioactive waste. The development of iron phosphate glasses for these applications faces a series of technical challenges. One is the lack of basic engineering data for phosphate glasses in general. Very little is known about the properties of these glasses, some being of great interest including: phase equilibrium in phosphate systems, particularly the surface liquidus, atomic glass structure iron phosphates, kinetic of nucleation and crystallization, resistance to corrosion and effect of radiation. This project is a joint contribution of three research institutions (UMR, UFSCar and CNEA) aiming to increase the understanding of these systems. The experimental program at UFSCar will focus mainly in crystallization kinetics of iron phosphate glasses. This will be carried through referring studies determination of crystallization type, analysis of crystallization products, determination of cooling critical rates and determination of nucleation and crystallization rates of iron phosphate glasses. Besides getting these data for glasses as received from UMR, UFSCar will also perform similar analysis for glasses irradiated at CNEA. The accomplishment of the above described tasks demands a substantial amount of DTA experiments, besides DRX experiments and optical microscopy, being important to stand out that UFSCar has the necessary infrastructure.