No abstract

No abstract

No abstract

The structure and mechanical properties of composites consisting of a metal matrix based on aluminum and its alloys of different compositions (AA-3003 and AA-5154) and graphene synthes sized in situ under a layer of molten salts were investigated depending on the chemical composition and grain size of the matrix. Aluminum matrix composites of three compositions were studied in as-cast coarse-grained, deformed fine-grained (grain size < 1 mm), and deformed sub microcrystalline (grain size < 1 μm) states in order to compare the structural characteristics of composites with different grain sizes. The composites were subjected to deformation with a split Hopkinson (Kolsky) bar and to dynamic-channel angular pressing. The hardness and dynamic mechanical properties of the composites were measured at strain rates ε˙ from 1.8 − 4.7 × 103 to 1.6 − 2.4 × 105 s−1. It was found that grain refinement induced a sharp increase in the hardness of composites with various compositions (by a factor of 1.6–2.6). A correlation of the elastic-plastic properties of the aluminum matrix composites with the grain sizes and chemical compositions of the matrices was established. A transition from coarse-grained to sub microcrystalline structure was shown to improve the elastic-plastic properties on average by a factor of 1.5. It was proved that the reinforcing effect of graphene increased with the decreasing grain size of the matrix. Mechanisms of reinforcement of the aluminum matrix composites using graphene were proposed.

Рассмотрены особенности формирования дисперсной структуры в Al сплавах с переходными металлами различных составов в литом и деформированном состояниях. Установлены закономерности деформационного поведения бинарных и многокомпонентных композиций, полученные методом динамического прессования и при кручении под высоким квазигидростатическом давлении. Ключевые слова: алюминиевый сплав, интенсивная пластическая деформация, структура, фазовый состав, свойства. The features of ultra-fine grained structure formation in different Al alloys with transition metals in cast and deformed states were studied. General trends in deformation behavior of binary and multicomponent compositions, obtained by dynamic channel-angular pressing and by torsion under high quasi-hydrostatic pressure were established.