Aluminum alloys are widely used in various industries due to their high specific characteristics of strength, corrosion resistance and manufacturability. The desire to further increase the operating temperatures of aluminum alloys has led to the development of alloys of the Al-Cu-Fe system, which demonstrate increased thermal stability compared to traditional aluminum alloys. The addition of additional alloying elements (X) to the Al-Cu-Fe system makes it possible to further optimize the microstructure and mechanical properties of these alloys, expanding their potential application at elevated temperatures.
The microstructure of Al-Cu-Fe alloys is characterized by the presence of intermetallic phases, such as AlxCuyFez, dispersed in an aluminum matrix. These intermetallics, which have high thermal stability, prevent grain growth and diffusion processes at elevated temperatures, ensuring the stability of the microstructure of the alloy. The introduction of additional alloying elements (X) can lead to the formation of new intermetallic phases, modify the morphology and distribution of existing phases, thus affecting the mechanical properties of the alloy. For example, the addition of manganese (Mn) can contribute to the formation of smaller and more evenly distributed intermetallic particles, improving the strength and ductility of the alloy.
The mechanical properties of Al-Cu-Fe-X alloys, such as tensile strength, yield strength, and elongation, depend on chemical composition, microstructure, and heat treatment. The high thermal stability of intermetallic phases allows Al-Cu-Fe-X alloys to maintain their strength at elevated temperatures, which is an important advantage over traditional aluminum alloys. The introduction of alloying elements (X) can significantly improve the mechanical properties of the alloy. For example, the addition of zirconium (Zr) can contribute to the formation of strengthening phases that increase the yield strength and ultimate strength of the alloy without significantly reducing ductility.
The thermal stability of Al-Cu-Fe-X alloys is their key characteristic, which determines the possibility of their application at elevated temperatures. Thermal stability is determined by the ability of the alloy microstructure to maintain its characteristics (grain size, phase distribution) under prolonged exposure to high temperatures. Studies show that Al-Cu-Fe-X alloys with optimal composition and heat treatment demonstrate excellent thermal stability, maintaining a significant proportion of their initial strength even after prolonged exposure to temperatures close to the melting point.
The choice and concentration of alloying elements (X) in Al-Cu-Fe-X alloys significantly affects their microstructure, mechanical properties, and thermal stability. Different alloying elements can perform different functions, such as:
Formation of strengthening phases: Zr, Ti, V
Modification of the morphology of intermetallic phases: Mn, Cr
Improved thermal stability: Nb, Ta
Improved corrosion resistance: Mg, Si
Optimization of the alloy composition, including the selection of the optimal combination of alloying elements (X) and their concentrations, is an important task for achieving the desired alloy characteristics.
Al-Cu-Fe-X alloys with excellent thermal stability are used in various industrial applications where high strength and stability of properties at elevated temperatures are required. These areas include:
Aviation industry: engine parts, fuselage skin
Automotive industry: engine parts, brake discs
Energy industry: heat exchangers, turbine blades
Al-Cu-Fe-X alloys are a promising class of aluminum alloys with excellent thermal stability and high mechanical properties at elevated temperatures. Selection of the optimal composition and heat treatment makes it possible to obtain alloys with specified characteristics for various applications. Further research is aimed at developing new Al-Cu-Fe-X alloys with improved characteristics, expanding the possibilities of their application in extreme temperatures.
Author: Andrea Školáková *,Pavel NovákORCID,Lucie Mejzlíková,Filip PrůšaORCID,Pavel Salvetr andDalibor Vojtěch
The Institute: Andrea Shkolakova, Pavel Novak, Lucie Meizlikova, Filip PrušaORKID, Pavel Salvetr iDalibor Vojtech, Faculty of Metallurgy and Corrosion Protection, University of Chemical Technology, Prague, Technická 5, 16628 Prague, Czech Republic