Development of a Nuclear Microprobe Technique for Hydrogen Analysis in Selected Materials.

摘要

The Lithium Nuclear Microprobe (LNM) has been developed to the point where it now is a unique and reliable nondestructive tool for the measurements of hydrogen concentration depth profiles in material surfaces. The hydrogen concentration calibration was performed using hydrogen-in-titanium NSB standards and Kapton, a polyimide film. Hydrogen surface concentrations were measured in cadmium and chromium plated D6AC steel samples,smooth and fractured Ti-6Al-4V surfaces that had been exposed to a stress corrosion environment,and smooth surfaces of 7075aluminum alloys that had been exposed to conditions of stress corrosion. Hydrogen concentration depth profiles were measured in cadmium plated D6AC steel and 7075aluminum alloy samples. Very high hydrogen concentrations found in these samples were linked to mechanical property degradation and corrosion. Thus the LNM has emerged as a proven,currently unmatched,diagnostic technique for accurate in situ measurements of localized hydrogen concentrations. (Modified author abstract)