Spark plasma sintering synthesis and mechanical spectroscopy of the ω-Al_0.7Cu_0.2Fe_0.1 phase

Abstract

Starting from a mixture of Al–Cu–Fe quasicrystalline (QC) particles and Al powder, a fully dense and almost Al–Cu–Fe ω single-phase alloy was produced by spark plasma sintering. This technique allows synthesising large samples with sizes suitable for mechanical spectroscopy experiments. Mechanical spectroscopy was selected because it is a relevant tool for detecting the presence of structural defects at both nano and microscopic scales. Young’s moduli were measured in the 15 kHz range as a function of temperature by the resonant frequency method. Young’s moduli behave similarly for typical metals and exhibit values that are comparable to those of the Al–Cu–Fe QC phase. The damping coefficient Q ⁻¹ was determined at various temperatures between room temperature and 840 K over a large frequency range, i.e. between 10⁻³ and 10 Hz. The results suggest that solid friction effects do occur. In addition, a relaxation peak is observed in the intermediate temperature range.