Effect of alumina addition on the sintering behavior and dielectric properties of a borosilicate glass

• Main Authors: Zhi-Wei Lian, 連智偉
• Other Authors: Wei-Hsing Tuan
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/15293716804314780490

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 90 === Abstract In the present study, a glass-ceramic is prepared by using a borosilicate glass and alumina with various particle size. The sintering behavior and dielectric properties of the borosilicate glass/alumina composites are investigated. In the XRD patterns, all the composites, no new phase is formed in after sintering; the composites were composed of α-phase alumina and amorphous borosilicate glass. The borosilicate glass can achieve high density after sintering at 720℃. However, the addition alumina particles prohibit the densification of glass matrix. The densification rate decreases with increasing alumina content and with decreasing particle size of alumina. When the alumina particles formed a contiguous network, the densification rate is further hampered. At higher alumina volume fractions and smaller alumina size, the experimental results do not agree with a self-consistent model and a composite sphere model. For the dielectric properties, the factors which affected the dielectric constant are relative density and alumina content. Increasing relative density and alumina content raise the dielectric constant. The porosity and sodium content of alumina affect the value of dissipate factor. The dissipate factor can be dramatically increased due to increase of the sodium content in alumina. The dissipate factor increases with decreasing relative density. The dissipate factor of the borosilicate glass is lower than all the borosilicate galss/alumina composites because of the presence of Al2O3/glass interface.