Effect of Fe Substitution on the Stabilization of the Icosahedral Phase in Al-Cu-V alloys

✍ Scribed by D.K. Misra; R.S. Tiwari; O.N. Srivastava

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 190 KB
• Volume: 36
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/1521-4079(200106)36:4/5<419::aid-crat419>3.0.co;2-q

✦ Synopsis

The effect of Fe substitution on the formation and stabilization of icosahedral phase in Al-Cu-V alloys has been investigated by employing transmission electron microscope and X-ray diffraction. In the as quenched Al 75-x Cu 15+x Fe 5 V 5 alloys with x=0, 5 and 10 it has been found that grain size of icosahedral phase increases from 156nm to 0.53µm with increasing x. All the three alloys exhibit the formation of α-Al and θ-Al 2 Cu phases along with the i-phase. The nanoquasicrystalline and α-Al phases in Al 75 Cu 15 Fe 5 V 5 alloy transform to Al 7 Cu 2 Fe phase by annealing at 550°C for 4 hrs by peritectic type of reaction. A curious type of pseudo-twelve fold electron diffraction pattern devoid of any diffuse scattering has been observed in some local regions of Al 65 Cu 25 Fe 5 V 5 alloy. The angles and details of twelve sectors are varying alternatively. A plausible explanation in terms of microtwin domains of θ-Al 2 Cu structure in [110] orientation has been given to explain the characteristic features of the pseudotwelve fold pattern.