Accession Number : AD0813860

Title :   DEVELOPMENT OF NONDESTRUCTIVE TESTING METHODS FOR THE EVALUATION OF THIN AND ULTRATHIN SHEET MATERIALS.

Descriptive Note : Final rept. 16 Jul 65-15 Jun 66,

Corporate Author : GENERAL AMERICAN TRANSPORTATION CORP NILES ILL GENERAL AMERICAN RESEARCH DIV

Personal Author(s) : Kubiak,E. ; Hosek,R. ; Lichodziejewski,W.

Report Date : FEB 1967

Pagination or Media Count : 78

Abstract : This report describes activity on the subject program for the third year. Electronic modifications were made to the FM Lamb wave system during the period which resulted in a signal-to-noise ratio improvement of better than one order of magnitude. In addition, the use of a sound absorbing medium in the area of the transducers was found to significantly reduce 'crosstalk' and stray reflections. Laboratory testing with the FM Lamb wave system has proved the technique to be capable of detecting small 'flaws' or 'defects', but relatively insensitive to material property variations. A brief analytical investigation of a forked-coil eddy current system has shown that the technique can be effectively used to measure material properties of only certain alloys provided sheet thickness is simultaneously monitored. A theoretical and experimental investigation of beta backscatter has shown the method to be related to thin sheet hardness and surface finish by a second order effect. Theoretical and experimental work on a 'counterfeit waveguide' microwave technique for measuring material properties has been encouraging and further work is recommended to reduce the technique to practice. A survey of thin sheet manufacturers and users has established the fact that most of the present thin sheet problems requiring continuous on-line inspection are indigenous to the manufacture and fabrication of refractory materials. (Author)

Descriptors :   (*SHEETS, *NONDESTRUCTIVE TESTING), ULTRASONIC RADIATION, DEFECTS(MATERIALS), MONITORS, SENSITIVITY, THICKNESS, MICROWAVES, SURFACE PROPERTIES, HARDNESS, MAGNETIC PROPERTIES, STAINLESS STEEL, ALUMINUM, NIOBIUM ALLOYS, DIFFUSION BONDING, METAL JOINTS

Subject Categories : Fabrication Metallurgy
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE