The microstructure analysis of Al–Cu–Cr phases in Al65Cu20Cr15 quasicrystalline particles/Al base composites

An investigation of the Al–Cu–Cr phase diagram: Phase equilibria at 800–1000°C

“…Consequently, the formation and thermal stability of the phases forming in high-Al alloys were examined (see [1][2][3][4][5][6][7][8][9][10][11][12] and references therein).…”

“…Apart from the quasicrystals, a great number of periodic structures were reported in either rapidly solidified or annealed alloys [4][5][6][7][8][9][10][11]. None of these results were correlated with those on the corresponding phase diagram and these results are difficult to analyze systematically.…”

Formation of decagonal quasicrystals in mechanically alloyed Al–Cu–Cr powders

“…the chemical composition is given in at%. To choose the compositions we based either on the data on the composition of quasicrystalline phases in the related systems (for example, in the system Al--Cu--Fe, the icosahedral quasicrystalline phase forms at the composition of Al 65 Cu 23 Fe 12 ), or on the works, devoted to the the system under investigation [26]. The mechanical alloying of Al 67 Cu 20 Cr 13 and Al 75 Cu 10 Cr 15 elemental mixtures was performed for 1 h. It should be noted that due to the adhesion of milled powder to balls and the wall of vial of planetary ball mill, the produced amount of powder was of from 20 to 80% of the loading powder amount, depending on the sample composition.…”

“…The quasicrystalline phases in this system can be formed by melt quenching; in some cases, quasicrystals are formed by annealing of quenched alloys [23][24][25][26][27]. No data about the thermodynamic stability of the QC phases in this system are available.…”

“…It is known that both icosahedral [23][24][25][26] and decagonal [26][27] crystalline phases can be obtained in the Al--Cu--Cr system. As was found in [26], the decagonal phase is formed in the alloys, which are close to Al 75 Cu 12 Cr 13 in the chemical composition, whereas the icosahedral phase is formed in the Al 66 Cu 22 Cr 12 alloy, i.e., at the Al and Cu concentrations typical of the icosahedral phase in the Al--Cu--Fe system [15][16][17][18][19]. On the other hand, the formation of an icosahedral phase was observed in [27] for the Al 75 Cu 10 Cr 15 composition, i.e., the phase formation in this system depends not only on the chemical composition, but also on the method of alloy preparation.…”