Accession Number : AD0720239

Title :   Application of Photochromic Coatings for Nondestructive Inspection.

Descriptive Note : Final technical rept. Jan 69-Jul 70,

Corporate Author : AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Allinikov,Sidney

Report Date : DEC 1970

Pagination or Media Count : 61

Abstract : The application of a photochromic compound to provide a NDT technique for aerospace materials and structures is discussed. The photochromic compound, incorporated into a paint formulation, is converted from a white to a bright violet color upon a brief irradiation from an ultraviolet source. The colored paint surface is then heated by any suitable means, such as a hot air blower. Heat serves to bleach the paint to the original white color. Defects are disclosed because heat conductivity at the defect site is different from that of the rest of the area under inspection. The defect thus appears as a colored or white area dependent upon the nature of the defect and originating direction of the heat source. Some of the types of defects and kinds of structures to which the NDT paint has been applied are discussed, along with advantages and limitations of the paint. (Author-PL)

Descriptors :   (*NONDESTRUCTIVE TESTING, *PHOTOCHROMISM), DEFECTS(MATERIALS), THERMAL CONDUCTIVITY, PAINTS, TEST METHODS, SPIRO COMPOUNDS, BONDED JOINTS, COMPOSITE MATERIALS, LAMINATED PLASTICS

Subject Categories : Polymer Chemistry
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE