ELASTIC PROPERTIES ON MICROSTRUCTURAL DEPENDENCE ON PHOSPHATE BASED BIOACTIVE GLASSES FOR BIOMEDICAL APPICATIONS

摘要

In recent years, bioactive glasses have gained considerable interest among scientistsrndue to their potential applications such as replacement of damaged / diseased bodyrnparts in the medical field. One has to optimise the composition of bioactive glasses forrnthe effective bonding with bone / dental applications. Therefore, the preparation of thernsame with different compositions to improve the bioactivity and thereby, therncharacterisation of the physical, chemical and mechanical properties of bioactivernglasses are essential. Ultrasonic non-destructive characterisation of materials is arnunique tool not only for the defects identification in industries, but also for materialsrncharacterisation over wide range of temperatures. In the present investigation,rnbioactive glasses in or near the bioactive region on Si-Al-K-Na-B-Ce-Ca-Ba-Ti (P2O5rnfree), Si-Al-K-Li-Na-Zr-P and Si-Al-Na-Ca-Mg-P systems have been prepared forrndifferent compositions by normal melting and annealing technique. The ultrasonicrnvelocities and attenuation measurements have been made at a fundamental frequencyrnof 5 MHz at room temperature on the above bioactive glasses for different thermalrntreatment conditions. The ultrasonic velocity and attenuation measurements werernmade for different frequencies. The frequency dependence attenuation were fitted intorna linear relation a = a f N. The observed increase in density, velocities and elasticrnproperties of bioactive glasses as a function of thermal treatment temperature in thernabove bioactive glasses are due to increase in network bonds per unit volume and notrndue to structure rearrangement / cross- link changes. Thus, the observed results havernbeen found to be useful in optimising the composition of bioactive glasses for suitablernbiomedical applications.