In general, the mechanical properties of an alloy are determined by the microstructure that results from the alloy’s thermo-mechanical history. The thermo-mechanical path in alloy processing is chosen to take advantage of a least one of several strengthening mechanisms such as grain size, dispersion strengthening or dual phase structures. Optimization of an alloy’s strength is accomplished by control of the microstructure which determines the operative strengthening mechanism. Therefore NDE techniques sensitive to microstructural changes should prove useful in detecting mechanical property differences. In this work, various thermo-mechanical treatments have been used on aluminum and titanium alloys to provide a wide range of mechanical properties. From the results obtained it is concluded that selection of an NDE detection plan depends on the alloy’s thermo-mechanical history and will vary with alloy system.