Diffusion Coating Process for Columbium Base Alloys
Abstract
A study was conducted to improve and optimize coatings for columbium alloys, protective in air to 2600 deg F for at least 10 hours. Process variables of two different silicide base coating systems (Si-Cr-Al and Si-Cr-B) applied by a two-step pack cementation process were optimized by statistical methods. Coatings were evaluated on D-31, C-103, Cb-1Zr (FS-80), and FS-82 columbium alloys. Oxidation resistance testing included furnace testing in moving air, sustained load thermal cycling, propane torch and ram-jet tests. Tensile strength and bend properties of uncoated and coated alloys were evaluated at room and elevated temperatures. An analytical evaluation of these systems was conducted to characterize the coating components. In addition, oxidation tests in the range 1000 to 2000 deg F were conducted to determine "di-silicide pest" effects on the two systems. The Si-Cr-B system was unaffected by this phenomenon.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1964
- Accession Number
- AD0603002
Entities
People
- Aleck B. Featherston
- Brennan A. Forcht
- Gordon W. Bourland
- Kent P. O'kelly
- William L. Aves Jr.
Organizations
- Vought