WETTING AND BONDING BETWEEN ALUMINUM ALLOYS AND SAPPHIRE.
Abstract
Wetting and bonding between the basal plane of single crystal sapphire and several aluminum alloys were investigated by the sessile drop technique at 1300 F and 1600 F in vacuo of 0.0001 torr. The alloys were commercially pure (99+ percent) aluminum, commercially pure aluminum with small additions of each of eleven elements, and three commercial aluminum alloys. Additions of zirconium, magnesium, and copper lowered the aluminum-sapphire equilibrium contact angle; the lowest contact angle observed was 94 degrees and was obtained with 0.94 atomic percent addition of magnesium to pure aluminum. The contact angle was not affected by additions of lead, vanadium, manganese, chromium, and bismuth, whereas it was increased by additions of selenium, tellurium, and germanium. Although no general relationship was observed for the effect of the alloying elements on the aluminum-sapphire bond strength, the highest strengths (up to 13,000 psi) were observed when failure occurred in the metal rather than at the interface. Metallographic examination of the aluminum-sapphire interfaces indicated that when the temperatures of the molten alloys were less than 1700 F, the depth of the interfacial zones in the sapphire was less than 0.1 micron. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1966
- Accession Number
- AD0638523
Entities
People
- Albert P. Levitt
- James Brown
- Stanley M. Wolf
Organizations
- United States Army Research Laboratory