Interfacial phenomena in TLP bonding of Al۲O۳ using a Bi۲O۳ interlayer

Bismuth oxide, due to its low melting point was selected as filler for joining alumina to aluminausing Transient Liquid Phase (TLP) method. For this purpose a thin layer of bismuth oxide wasplaced as an interlayer between the ceramic bodies. The growth of interfacial compoundsbetween Al۲O۳ and Bi۲O۳ during transient liquid phase bonding at ۹۰۰ and ۱۰۰۰۰C for varioustimes was investigated. The mechanical properties of the joined samples were measured usingshear testing method. To investigate the microstructure of the joining area, the cross section ofthe joints were studied using scanning electron microscope (SEM) and X-ray diffractionmethod. The results showed that increasing the time and temperature resulted in bismuth oxide(Bi۲O۳) diffusion into alumina (Al۲O۳) and forming interfacial compounds. The highest jointstrength of about ۸۰ MPa was obtained for the samples joined at۹۰۰°C for ۱۰hrs.

Keywords:

Alumina , Bismuth oxide , TLP , Interfacial Compounds.