Effect of particle size distribution of alumina on strength of glass-infiltrated alumina

Effect of sapphire particle size on transmittance and strength of sapphire glass composites prepared by melt infiltration

“…The microstructural evolution on grain growth of alumina particles in the presence of glass has been studied extensively. In the penetration of sintered alumina by glass, the smallest grains visible during the initial penetration disappeared with time, and the alumina grains became prismatic in shape due to the formation of the lowest energy crystallographic faces, as reported in the literature 12…”

“…Crack propagation was mainly intergranular. Lim et al, 12 however, reported that these elongated grains with heterogeneous grain growth were a major cause of the degradation of strength due to the formation of grains with an irregular shape, such as abnormal grain growth in solid state sintering. They also reported that the glass infiltrated alumina composite with alumina particles with a bimodal particle distribution showed lower strength due to the growth of exaggerated grains.…”

“…A previous study 12 examined the grain growth of alumina particles in glass infiltrated alumina composites suggested that the fine alumina particles dissolved much more easily in the glass melt than coarse ones, and Al 3z and O 22 ions in the glass melt then reprecipitated on the pre-existing alumina particles to make them grow. This dissolution and reprecipitation phenomenon could be observed more easily at higher infiltration temperatures.…”

“…In the penetration of sintered alumina by glass, the smallest grains visible during the initial penetration disappeared with time, and the alumina grains became prismatic in shape due to the formation of the lowest energy crystallographic faces, as reported in the literature. 12 However, the strength, transmittance and grain growth of sapphire grains in glass infiltrated sapphire have not been studied. The present study examined the effect of the sapphire particle size on the light transmittance, strength and microstructure of glass infiltrated sapphire composites.…”

Influence of Multi-cycle Infiltration on Porosity and Optical Properties of Glassinfiltrated Alumina Biocomposites for Dental Restorations

“…Despite their high clinical success rate, reported to vary between 72 and 87% after 10 years, [1] inappropriate aesthetics due to opacity and allergic reactions to metals have led to the development of all-ceramic prostheses [2]. Good aesthetics for artificial teeth can be obtained using glass-infiltrated alumina biocomposites, which can be translucent enough to mimic the characteristics of the natural teeth, [3] yet keeping an excellent, accurate marginal and internal adaptation after multiple heat treatments [4]. The good marginal adaption of these glass-infiltrated alumina biocomposites is related to the low shrinkage of the final material, [5] which is below 0.5%, due to the fact that pre-sintering of the preform and infiltration of the glass are performed at relatively low temperatures [6].…”