Coherent ultrasonic backscatter within a textured titanium alloy

The ultrasonic scattering from microtexture regions within a Ti-6Al-4V titanium alloy are analyzed for mode-converted shear wave interactions. Crystallographic orientation information gathered from electron backscatter diffraction (EBSD) measurements is used to guide the analysis, where critical orientations of the microtexture crystallites were identified and analyzed with respect to misorientation states, grain feature sizes, and shear wave propagation directions. The analysis suggests that large, aligned microtexture features within the titanium alloys can efficiently scatter and reflect the ultrasonic energy in a coherent manner when feature size, grain misorientation states, and grazing-incidence conditions are met for the shear-wave inspection fields. Analysis results are provided for a representative MTR feature which had generated a strong backscatter signal response. The results are expected to be important for NDE polycrystalline material inspections and characterization in titanium material aerospace applications.