INFLUENCE OF DISPERSION PARTICLES OF Al_3Li AND Al_3Sc CROSSCUT BY DISLOCATIONS ON PROPERTIES OF ALUMINUM ALLOYS

摘要

Secondary particles of metastable delta' (Al_3Li) and stable Al_3Sc phases occur in the phase composition of aluminum alloys containing lithium and scandium as alloying components. These particles are spherical in form and until they attain certain dimensions, are entirely coherent to the aluminum matrix and may be crosscut by slip dislocations. The presence of particles of delta' (Al_3Li) or presegregations of these phases having long-range order promotes localization of deformation in pressure treatment and in the course of mechanical tests of samples. This feature exerts a noticeable effect on the industrial plasticity of alloys and on the level and nature of the anisotropy of the mechanical properties of thermally treated intermediate products.