X-ray studies of structure defects in nanostructured Al-4wtCu alloy

摘要

The process of nanocrystalline structure formation during mechanical milling was studied in Al-4wt%Cu alloy. X-ray patterns were analyzed to determine the crystallite size, the lattice strain, probability of the stacking faults and the lattice parameters. As a result, nanocrystalline powders have been synthesized with microstructure showing a mixture of highly strained crystallites. High level of lattice strain is achieved as a result of mechanical milling. This fact can reflect a significant increase in the numbers of defects created. SEM results show that welding of very small particles to the surface of big particles was occurred and the powder particles tend to form a matrix of randomly welded thin layers of highly deformed particles. The microstructure, observed by TEM, was composed of nanometric grains and the statistical average grain size is about 29 nm.