Biaxial flexural strength of glass-ceramics crystallized by microwave energy

• Grant number: 18/20429-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2018
• End date: October 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Guilherme de Siqueira Ferreira Anzaloni Saavedra
• Grantee: Gustavo Macedo Pereira
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

The objective of this work will be to analyze the fatigue resistance of two glass-ceramic conventionally crystallized or crystallized by microwave energy. 120 discs with 1,2 millimeters thick and 12 millimeters in diameter will be made and these will be distributed randomly in groups according to the crystallization form. An X-ray diffraction analysis will be performed in two samples of each group, aiming to characterize eventual changes in crystallinity as a function of the methods used. The biaxial flexural strength calculation will be performed (based on the monotonic test) in 5 samples of each group, which will serve as a parameter for the definition of the fatigue test loading rates. The other specimens will be distributed in the ratio 9:6:3 and tested under step stress fatigue in three load profiles (mild, moderate and aggressive), varying the load increments and the number of cycles. The fractured specimens will be evaluated in stereomicroscope and scanning electron microscopy (SEM), for superficial analysis and analysis of fracture characteristics. Survival or fracture data will be used to calculate Weibull's beta (²) value and reliability for given missions. The probability of survival - according to load and time (number of cycles) - will be calculated using specific software for fatigue analysis (Synthesis 9, Alta Pro and Weibull ++, Reliasoft, Tucson, AZ, USA).