Electron backscattering diffraction analysis of mechanically milled and spark plasma sintered pure aluminium

Analysis of the spark plasma sintering (SPS) microstructures fabricated from 8 h mechanically milled (MMed) pure aluminium powder was undertaken via orientation image maps (OIMs) obtained via the electron backscattering diffraction (EBSD) technique. EBSD analysis clearly revealed that the SPS material possessed a mixture of fine grains approximately 300 nm in diameter and coarse grains 2–5 μm in size. This bimodal aluminium matrix grain structure exhibited the crystallographically random textures and grain boundary misorientations that are virtually all high angle (>15°).