A comparison of the wettability of copper-copper oxide and silver-copper oxide on polycrystalline alumina

• Published in: Journal of materials science Vol. 30; no. 19; pp. 4781 - 4786
• Main Authors: MEIER, A. M, CHIDAMBARAM, P, EDWARDS, G. R
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.10.1995
• Subjects: Applied sciences; Chemical and electrochemical properties; Exact sciences and technology; Metals. Metallurgy; Temperature dependence; Polycrystal; Copper base alloys; Brazing; Contact angle; Experimental study; Wettability; Transition metal alloy; Spreading; Infiltration; Sessile drop method; Alumina; Application; Silver base alloys
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/bf01154485

The contact angles of liquid silver-copper oxide/alumina and liquid copper-copper oxide/alumina systems were determined using the sessile drop method. Copper oxide (CuO) additions of 1.5-10.0 wt.% were made. Temperatures of 970-1250 deg C for the silver-based alloys and 1090-1300 deg C for the copper-based alloys were studied. Minimum contact angles of 42plus/minus8 deg and 64plus/minus7 deg were obtained for the copper-copper oxide alloysand the silver-copper oxide alloys, respectively. The contact angle was approximately constant for the silver-copper oxide alloy within the immiscible liquid composition range. While the contact angles were higher for the silver-based alloys relative to the copper-based alloys, successful infiltration of a porous alumina sample was achieved at only 1050 deg C for a Ag-10 wt.% CuO alloy. Compression tests on infiltrated samples revealed similar compressive strengths for alumina samples infiltrated with silver-copper oxide alloys, silver-copper-copper oxide alloys and copper-copper oxide alloys. The compressive fracture strength for the infiltrated samples was an order of magnitude higher than the fracture strength of the porous alumina body without infiltration. Although silver-based alloys are more expensive than comparable copper-based alloys, in many applications the additional cost may be offset by lower processing or brazing temperatures, improved thermal and electrical conductivity, and improved toughness.