The microstructure-strength relationship in severely-deformed commercial-purity titanium

Electron backscatter diffraction was applied to examine the microstructure developed in commercial-purity titanium subjected to equal channel angular pressing at 200 °C to a true strain of 8.4. The microstructure was characterized by a mean grain size of 0.4 μm and fraction of high-angle boundaries of 55%. However, it also contained a significant fraction of relatively coarse (>1 μm) remnants of original grains. A microstructure-properties analysis indicated that strengthening effect of ECAP was essentially contributed by substructure.