IDENTIFICATION OF CHEMICAL HETEROGENEITY WITH THE USE OF COLOUR METALLOGRAPHY AND EDS OF THE AICu4Mg1 ALLOY

摘要

Aluminum alloys, which have a higher content of alloying elements, are prone to crystal segregation. This segregation will significantly affect the physical, mechanical and chemical properties of these alloys. Crystal segregation is essentially micro-scale chemical heterogeneity and occurs during alloy crystallization. The experimental work described in the paper is focused on the identification of chemical heterogeneity in the alloy EN AW-2024 (AlCu4Mg1). It is one of the most important aluminum alloys, which is intended for use in the aerospace and military sectors in the fuselage applications of such areas as wing tensioning structures and elements. To refinement of the structure and improve the mechanical properties, the alloy was inoculated with AlTi3B1 in various concentrations and the effect of this inoculant on the refinement of the structure was studied. The formation of crystal segregation in Al alloys cannot be prevented, but its extent can be influenced, or it can be suppressed by the correct choice of parameters using heat treatment, which was applied in this experiment as well. Optical microscopy and EDS analysis were used to evaluate experimental samples, by which the distributions of individual elements and phases were documented.