Author: Bo Liang, Baoyan Zhang, Guodong Wang, Di Li,Xiaoming Zhang
Institute: Department of Metallurgy and Materials Science, Faculty of Engineering, University of Birmingham, Birmingham B15 2TT, UK
The powder component mixture with the given composition Al65Cu20Fe15 was subjected to mechanical milling for 8 hours. Then, the milled powders were annealed at different temperatures in the range of 600–800 °C for 4 hours. X-ray diffractometry, differential scanning calorimetry and electron microscopy were used to analyze the microstructure of the products before and after annealing. The icosahedral quasicrystalline phase was not formed immediately after milling. This QC phase was obtained from the unmilled powder by annealing at a temperature above 700 °C for 4 hours. However, the combination of milling and annealing can promote the formation of QC at temperatures above 600 °C.
Quasicrystals (QC) are a third state of solids, along with classical crystalline and amorphous states. They have a long-range orientation order without translational order. These materials are characterized by high strength and rigidity, as well as low electrical and thermal conductivity. Detailed studies on the synthesis of quasicrystals, especially in the Al–Cu–Fe system, have shown interest in methods such as mechanical alloying (MA) due to the possibility of efficient powder production for subsequent applications. This paper examines the effect of a combination of mechanical milling and heat treatment on the formation of quasicrystals in Al65Cu20Fe15.
In recent decades, quasicrystals have attracted considerable attention from researchers due to their unique properties that distinguish them from traditional crystalline structures. This paper examines the formation of a quasicrystalline phase in mechanically alloyed Al65Cu25Fe15 alloy. The mechanical alloying process allows achieving significant homogeneity in the distribution of elements, which is of key importance for the formation of a quasicrystalline lattice.
When mechanically acting on a powder mixture of aluminum, copper and iron, complex processes of deformation and martensitic transformation occur, which stimulate the formation of new phases. As a result of long-term mixing and consolidation, as well as subsequent sintering, quasi-crystalline microstructures are formed, which have high heat resistance and rigidity.
The investigation of quasicrystalline phases in this alloy also highlights the importance of thermodynamic conditions and processing time in determining the transitions between different crystalline states. Thus, the results of this study may be useful in developing new materials with predetermined properties for high-temperature and aggressive environment applications.