Effect of crystallinity on crack propagation and mineralization of bioactive glass 45S5

• Author / Creator

  Kashyap, Satadru

• Bioactive glasses are a type of ceramic material designed to be used as bioresorbable therapeutic bone implants. Thermal treatment of bioactive glass ceramics dictates many important features such as microstructure, degree of crystallinity, mechanical properties, and mineralization. This study investigates the effects of temperature, time, and heating rates on the crystallization kinetics of melt cast bioactive glass 45S5. Bulk crystallization (three dimensional crystallite formation) was found to always occur in bulk bioactive glass 45S5 irrespective of the processing conditions. A comparative study of crack paths in amorphous and crystalline phases of bioactive glass 45S5 revealed crack deflections and higher fracture resistance in partially crystallized bioactive glass. Such toughening is likely attributed to different crystallographic orientations of crystals or residual thermal mismatch strains. Furthermore, in vitro immersion testing of partially crystalline glass ceramic revealed higher adhesion capabilities of the mineralized layer formed on amorphous regions as compared to its crystalline counterpart.

• Subjects / Keywords

  • Avrami kinetics
  • Crack propagation
  • Mineralization
  • Bioactive glass ceramic
  • Crystallization

• Graduation date

  Fall 2010

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3WP63

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.