An X-ray diffraction study on dislocation microstructure of as-prepared Al-Al2O3 composites

Abstract Microstructure of α-Al 2 O 3 containing Al-based composites were studied in terms of ab initio quasi-composite model of dislocation cell structure and ellipsoidal log-normal distribution of crystallite size. α-Al 2 O 3 , present in the composites, affects dislocation motion during stress relaxation at room temperature and may produce such a dislocation sub-structure. The region of high (∼8 × 10 9 cm −2 ) and low (∼2 × 10 9 cm −2 ) dislocation density has been characterized as cell walls and cell interiors, respectively, with compressive and tensile stresses, respectively, in accordance with the quasi-composite model. The results are in gross agreement with TEM studies.