Rapid Assessment of Surface Treatment Effectiveness and Degradation by Direct Field Measurement

Conventional nondestructive inspection (NDI) technologies do not have the ability to reliably and efficiently measure and quantify the effects of surface and subsurface residual stresses in aerospace structures. As part of a National Science Foundation Small Business Innovative Research (SBIR) program and several commercial projects, Positron has successfully demonstrated the ability to apply Induced Positron Analysis (IPA) in a single measurement to nondestructively quantify shot peen and cold expansion induced residual stress and relaxation effects in single crystal superalloys, steels, titanium and aluminum. IPA has demonstrated the ability to quantitatively measure residual stress effects throughout the operational life-cycle of the structural material -from determining the effectiveness of the initial treatment to tracking the operationally-induced changes over the life of the treated component. Use of IPA to nondestructively quantify surface and subsurface residual stress effects in critical structural, turbine engine, and gearbox materials and components will significantly improve the understanding of the effects of material treatments and operational usage on the durability and fatigue life of critical components at the microscale level.