Author: E. Giacomettia, N. Baluc, J. Bonneville, J. Rabier
Institute: Laboratory of Physical Metallurgy, University of Poitiers, SP2MI-Teleport 2-BP 179, 86960 Futuroscope, France
Microindentation of icosahedral Al-Cu-Fe quasicrystal is a topical research topic in the field of materials science. This unique material, possessing properties characteristic of both crystalline and amorphous structures, demonstrates high mechanical characteristics and resistance to certain types of destruction.
When conducting microindentation, the behavior of quasicrystals under the influence of localized loads is analyzed, which allows us to identify patterns in the distribution of stresses and deformations. As a result of using this method, it is possible to obtain information on the depth of penetration of indenters, as well as on the nature of the resulting microdestructions.
Many microindentation experiments have been performed on icosahedral quasicrystals (QCs) under room temperature conditions. The results have shown that quasicrystals such as Al-Cu-Fe, Al-Pd-Mn, Al-Li-Cu, Al-Ru-Cu, and Mg-Zn-Y have high hardness and relatively low tensile strength. Other compression tests have shown that these materials undergo a brittle-to-ductile transition (BDTT) at approximately 0.7 Tm, where Tm is the melting temperature. Several high-temperature microindentation studies have been published that investigated both brittle and ductile states. However, the temperature dependence of the hardness of icosahedral crystals has been reported only for Al-Li-Cu and Al-Pd-Mn.
The purpose of this paper is to present the results of microindentation on Al-Cu-Fe alloy over a wide temperature range. These results are compared with previous data obtained in compression experiments.
Samples of the polyquasicrystal composition Al63.5Cu24.0Fe12.5 were obtained by melting the components in a vacuum induction furnace and subsequent annealing. Analysis showed that the microhardness of Al-Cu-Fe is high and the fracture toughness is extremely low at room temperature. These characteristics are comparable with data for other icosahedral quasicrystals and semiconductors such as silicon.
Despite the complexity of its structure, Al-Ku-Fe shows outstanding strength, which makes it the subject of large-scale research. A deeper understanding of the microindentation process will not only optimize the properties of this quasicrystal, but also expand the horizons of its application in various industries, including aircraft manufacturing, electronics and biomaterials. Thus, further work in this direction seems promising and multifaceted.