DEVELOPMENT OF NONDESTRUCTIVE METHODS FOR EVALUATING DIFFUSION-FORMED COATINGS ON METALLIC SUBSTRATES.
Abstract
A program began June 1965 to detect, define, and characterize, by nondestructive test methods, variables significantly affecting service life of diffusion-formed coatings on refractory alloys. Specimens representing three systems were studied: (1) TZM alloy with W-3 coating; (2) Cb 752 alloy with Cr-Ti-Si coating; (3) B-66 alloy with PFR 30 coating. In addition to the stated objectives, the following resulted: (1) improved furnace techniques eliminating failures from reaction with holding fixtures; (2) reliable techniques for nondestructive determining initial coating thickness by an 8 MHz eddy-current method; (3) means of determining substrate and oxygen diffusion progress and possibly detecting the breakaway point by an 8 MHz eddy-current method; (4) techniques available for inspection and process control based on eddy-current, radiographic, and dye-penetrant methods; (5) failure modes are controlled/affected by environment; furnace screening tests have value in screening for variables but simulated such service environments as met in the plasma arc jet are needed for finally determining coating potential. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1966
- Accession Number
- AD0810501
Entities
People
- R. C. Stinebring
- T. Sturiale