The microstructures of α-Al2O3-containing composites were studied in terms of an ab initio quasi-composite model of dislocation cell structures and ellipsoidal log-normal distributions of crystallite size. The α-Al2O3 affected dislocation motion during stress relaxation at room temperature, and could produce a dislocation sub-structure. The regions of high (about 8 x 109/cm2) and low (about 2 x 109/cm2) dislocation density were characterized by cell walls and cell interiors, respectively. These corresponded with compressive and tensile stresses, respectively; in accord with the quasi-composite model. The results were in overall agreement with transmission electron microscopy studies.

An X-Ray Diffraction Study on Dislocation Microstructure of As-Prepared Al–Al2O3 Composites. A.K.Deb, P.Chatterjee, S.P.Sen Gupta: Acta Materialia, 2004, 52[9], 2755-64