Development of High Strength Thermally Stable Al-based Alloys with Nanocomposite Structure

摘要

This report results from a contract tasking Institute for Metal Physics, NAS of Ukraine as follows: The demands on materials set by aerospace and aircraft manufacturers include the development of alloys possessing high strength-to-weight ratios and capable to withstand high temperature exposures during service. One of the promising classes of materials which may meet these requirements are Al-based alloys with nanocomposite structures formed by partial crystallization of amorphous precursors the strength of which may exceed 1500 MPa. Solution of the problems concerning alloys chemistry and ability to tailor of certain microstructures is of prime importance for the development of new nanostructured materials. The goals of the project are to perform the systematic experimental studies of the effects of alloy composition and thermal prehistory on glass-forming ability, thermal stability, crystallization behaviour and mechanical properties of a series binary, ternary and multicomponent Al-based alloys alloyed by transition metals and rare earths as well as to elaborate appropriate theoretical models of nanocrystallization processes. The main factors responsible for nanoscale microstructure formation will be determined from comparison of the experimental data with the model predictions. As a result a series of new Al-based alloys with nanocomposite structure with improved mechanical properties and enhanced thermal stability will be developed and the fundamental basis for the nanostructured alloys design will be created.