Effects of CuO Content on the Wetting Behavior and Mechanical Properties of a Ag-CuO Braze for Ceramic Joining

Journal Article · Thu Sep 01 04:00:00 EDT 2005 · Journal of the American Ceramic Society, 88(9):2521-2527

DOI:https://doi.org/10.1111/j.1551-2916.2005.00492.x· OSTI ID:15020805

Kim, Jin Yong Y; Hardy, John S; Weil, K Scott

A new silver-based joining technique referred to as reactive air brazing (RAB) has been recently developed for joining high temperature structural ceramic components of the type used in gas turbines, combustion engines, heat exchangers, and burners. It was found that additions of CuO to silver exhibit a tremendous effect on both the wettability and joint strength characteristics of the subsequent braze relative to polycrystalline alumina substrates. The effect is particularly significant at low CuO content, with substantial improvements in wetting observed in the 1 – 8 mol% range. The corresponding strength of the brazed polycrystalline alumina joints appears to be maximized at a copper oxide content of 8 mol%, with a maximum room temperature flexural strength approaching that of monolithic alumina. While further increases in oxide content lead to improved wetting on polycrystalline alumina, the effect on joint strength is deleterious. It appears that the formation of a continuous brittle copper-based oxide layer along the interface between the braze and alumina faying surface is responsible for the poor mechanical behavior observed in joints fabricated with higher CuO content brazes.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15020805
• Report Number(s): PNNL-SA-39895; AA1510100
• Journal Information: Journal of the American Ceramic Society, 88(9):2521-2527, Journal Name: Journal of the American Ceramic Society, 88(9):2521-2527 Journal Issue: 9 Vol. 88
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
BRAZED JOINTS
BRAZING
BRAZING ALLOYS
CERAMICS
COPPER OXIDES
FLEXURAL STRENGTH
MECHANICAL PROPERTIES
SILVER
WETTABILITY
air brazing
ceramic to metal joining