Microstructural Analysis of Cold-Sprayed Ti-6Al-4V at the Micro- and Nano-Scale
The microstructure of cold-sprayed Ti-6Al-4V is unlike the structure resulting from any other processing technique. The unique characteristics are derived from the solid state thermomechanical processing of predominantly martensitic feedstock powders. During deposition, these powders undergo high strain rate deformation, leading to shear band-induced transformation of martensitic grains into nano-scale martensite, equiaxed alpha structures, and nanostructured alpha grains. The resultant microstructure evolution is dependent on the magnitude and direction of shear undergone by the particles. The specific structure and mechanism for formation of these regions will be discussed in detail using nanohardness mapping, scanning electron microscopy, and transmission electron microscopy.
Keywordscold spray microstructure morphology Ti-6Al-4V transformation
Special thanks to U.S. Army Research Laboratory Contract #: W911NF-10-2-0098 for sponsoring and directing this research, as well as taking the time to consult and produce samples.
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