Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Al-Cu-Fe

Sortuj według:

Ogranicz wyniki do:

The Effect of Transition Metals on Quasicrystalline Phase Formation in Mechanically Alloyed Al65Cu20Fe15 Powder

Mitka M., Kalita D., Góral A., Lityńska-Dobrzyńska L.

Archives of Metallurgy and Materials

2020

Vol. 65, iss. 3

1129--1133

The effect of replacing iron with transition metals (M = Mn, Cr, Co) on the microstructure of mechanically alloyed Al65 Cu20 Fe15 quasicrystalline powder was examined by X-ray diffraction and transmission electron microscopy methods. Powders of various compositions were milled in a high-energy planetary ball mill up to 30 hours at a rotation speed 350 rpm using WC milling media. The amount of the fourth additions was constant in all powders and Fe atoms were replaced with Mn, Cr or Co in a 1:1 ratio, while the content of the Al and Cu was selected in two ways: they remained the same as in the initial ternary Al65 Cu20 Fe15 alloy or changed to obtain e/a ratio = 1.75 (optimal for icosahedral quasicrystalline phase). Quasicrystalline phase formed in the quaternary Al65 Cu20 Fe7.5 M7.5 powders, whereas in the second group of compositions only crystalline phases were identified.

Quasicrystalline phase formation in the conventionally solidified Al-Cu-Fe system

Gögebakan M., Avar B., Uzun O.

Materials Science Poland

2009

Vol. 27, No. 3

919--926

Structural characteristics and thermal behaviour of the conventionally solidified Al-Cu-Fe alloys with nominal compositions of Al70Cu20Fe10, Al65Cu20Fe15 and Al63Cu25Fe12 were investigated by X-ray diffraction, scanning electron microscopy, and differential thermal analysis techniques. Results show that a single quasicrystalline phase forms in a conventionally solidified Al65Cu20Fe15 alloy, being thermodynamically stable without phase transition up to the melting point. A cubic AlFe(Cu) solid solution, identified as ß phase, and a cubic AlCu(Fe) solid solution, identified as ? phase, were observed with quasicrystalline phase for Al63Cu25Fe12 alloy. Conventional solidification of Al70Cu20Fe10 alloy does not result in quasicrystalline phase formation. However, the formation of quasicrystalline phase in conventionally solidified Al70Cu20Fe10 alloy was observed after additional annealing at elevated temperature. SEM micrographs for Al70Cu20Fe10 and Al63Cu25Fe12 alloys after annealing at 700 °C for 4 h revealed the formation of pentagonal dodecahedrons in the quasicrystalline phase, with an edge size of about 30 žm.