| 摘要 |
An improved cobalt-base braze alloy composition and method for diffusion brazing are provided for use in repairing superalloy articles. The improved cobalt-base braze alloy composition includes nickel; at least one element selected from the group of rhenium, palladium, and platinum; at least one element selected from the group of boron and silicon; and the remaining balance consists of cobalt. This composition may also include aluminum, and the composition may be combined with one or more base metal superally compositions to form an improved diffusion braze alloy mixture. In the improved method for repairing superalloy articles, the foregoing mixture is applied to a region of the superalloy article to be repaired, heated to melt the cobalt-base braze alloy and join the base metal superalloy particles together and the entire mixture to the region being repaired, and subjected to a diffusion braze heat treatment cycle in order to break down undesirable phases and to diffuse the melting point depressants into the mixture. After cooling, an environmental coating is applied to the final repair composite, which composite significantly improves the cyclic oxidation resistance of the coating compared to the properties of the superalloy base metal. |
