Effect of TiO2 on the crystallization, thermal expansion and wetting behavior of Nd2O3-Al2O3-SiO2 glass ceramic filler

The crystallization behavior, microstructure, crystalline phases, microhardness, coefficient of thermal expansion (CTE), and wetting behavior of Nd2O3-Al2O3-SiO2 (NAS) glass ceramics with different TiO2 content were investigated. The results show that the content of crystals increases and the size of crystals decreases with the increase of TiO2 content. Moreover, the formation of Nd2SiO5 leads to the increase and the precipitation of Al6Si2O13 results in the decrease in the CTE value of NAS glass ceramics. As a result, the CTE of NAS glass ceramics can be controlled in the range of 4.2-9.2 x 10(-6)/degrees C. These values are suitable for matching bonding to most ceramics with different CTE. Indeed, contact angle measurement demonstrates that the NAS glasses with 3 %, 6 % and 9 % TiO2 possess excellent wettability on the Al2O3, ZrO2 and zirconia toughened alumina (ZTA) ceramic, respectively.