Accession Number : AD0810501

Title :   DEVELOPMENT OF NONDESTRUCTIVE METHODS FOR EVALUATING DIFFUSION-FORMED COATINGS ON METALLIC SUBSTRATES.

Descriptive Note : Summary rept. 1 Jun 65-30 Apr 66,

Corporate Author : AVCO MISSILES SPACE AND ELECTRONICS GROUP LOWELL MA AVCO SPACE SYSTEMS DIV

Personal Author(s) : Stinebring, R. C. ; Sturiale, T.

Report Date : NOV 1966

Pagination or Media Count : 87

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)

Descriptors :   *REFRACTORY COATINGS), *REFRACTORY METAL ALLOYS), (*NONDESTRUCTIVE TESTING, (*SUBSTRATES, DIFFUSION, HIGH TEMPERATURE, OXIDATION, CORROSION INHIBITION.

Subject Categories : Ceramics, Refractories and Glass
      Coatings, Colorants and Finishes
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE