Author: Gogebakan M., B. Avar, M. Tarakci
Institute: Department of Physics, Faculty of Arts and Sciences, Kahramanmaras Sutu Imam University, Kahramanmaras 46100, Türkiye
The microstructure of the conventionally solidified Al63Cu25Fe12 alloy is a complex combination of crystalline phases formed as a result of cooling processors and subsequent heat treatment. The main components – aluminum, copper and iron – form a variety of intermetallic compounds, which gives the alloy unique mechanical properties.
Increased strength is achieved due to the small, uniform cell of the crystal lattice, which helps to improve dislocation mobility and, consequently, to increase the yield strength of the material. Study of the microstructure using an electron microscope indicates the presence of large fragments of solid solution, as well as the presence of secondary phases such as Al2Cu and AlFeSi, which are formed as a result of diffusion of elements.
Mechanical tests show that the alloy has good impact resistance and high ductility, making it suitable for high-temperature and high-load applications. Optimization of heat treatment can further improve the properties of the alloy, thereby expanding its application in the aerospace and automotive industries. This study analyzed the microstructures and mechanical properties of Al63Cu25Fe12 alloy produced by a conventional method after different types of heat treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA) were used to examine the microstructures of castings and heat-treated specimens. The XRD results confirmed the presence of a quasi-crystalline icosahedral phase (i-phase) and crystalline phases corresponding to β-AlFe(Cu) (β-phase) and τ-AlCu(Fe) (τ-phase). Scanning electron microscopy clearly showed the formation of the i-phase with pentagonal dodecahedrons also visible in the heat-treated samples, while the intensity of the β-phase peak decreased with increasing temperature. The melting point of the i-phase was recorded at 890 °C. The mechanical properties of the as-cast and heat-treated samples were evaluated by the Vickers method, showing a microhardness (HV) of about 598 kg fmm-2 (5.86 GPa) and an elastic modulus (E) of 104 GPa. The plasticity characteristic of the material (δH) was 0.54.