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Title: Wetting and strength issues at Al/alpha-alumina interfaces

Journal Article · · Journal of the European Ceramic Society

The wetting behavior and strength at aluminum/alumina interfaces has been an active subject of research. Al/alumina applications include ceramic-metal composites and several applications for electronic industries. In this paper the interface strength and microstructure of Al/alpha-alumina was investigated. We discovered that in a solid-state joining, the strength of the joint increases with increasing joining temperature. In a liquid-state joining, the strength of the joint gradually decreases due to the formation of unbonded areas. The strength, sigma sub b, is expressed by the following equation as a function of unbonded area, A: sigma sub b = 2.22 A + 143 (70 percent {le} A {le} 100 percent). The highest strength reached 400 MPa when the interface was formed at around the melting temperature of aluminum. An aluminum layer close to the interface became a single crystal when it was bonded to a sapphire. The following crystallographic orientation relationship is established: (1{bar 1}1){sub Al}//(001){sub {alpha}}-Al{sub 2} O{sub 3}, (110){sub Al}//<100>{sub {alpha}}-Al{sub 2}O{sub 3}. Amorphous alumina islands were formed at the interface. In the amorphous alumina, gamma-alumina nanocrystals grew from the sapphire, with the same orientation relationship to sapphire as above.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Director. Office of Science. Office of Basic Energy Sciences; 21COE program. Ministry of Education Culture Sports Science and Technology (US)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
827082
Report Number(s):
LBNL-52952; JECSER; R&D Project: 502401; TRN: US200425%%239
Journal Information:
Journal of the European Ceramic Society, Vol. 23, Issue 15; Other Information: Journal Publication Date: 2003; PBD: 15 Apr 2003; ISSN 0955-2219
Country of Publication:
United States
Language:
English