Abstract
Rapidly solidified Al-Zr-Ti alloys are far from thermodynamic equilibrium. Electrical resistance measurements revealed two stages of microstructure changes occurring at elevated temperatures. Using the results of X-ray diffraction analysis the first stage was explained by the precipitation of the metastable Al₃(Zr_xTi_1-x) phase with L1₂ structure and the second stage by the formation of the stable Al₃(Zr_xTi_1-x) phase with DO₂₃ or DO₂₂ structure. Ti atoms substitute for Zr atoms in the lattices of these phases. This substitution improves the lattice mismatch between the particles of the Al₃(Zr_xTi_1-x) phase and the matrix and shifts the individual decomposition stages to higher temperatures. Consequently, a better structure and strength stability may be expected.

Key words
Al-based alloys for elevated temperatures, rapid solidification, phase transformations, electrical resistance, X-ray analysis

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