Journal of Materials Science, Vol.47, No.1, 169-175, 2012
Spark plasma sintering synthesis and mechanical spectroscopy of the omega-Al0.7Cu0.2Fe0.1 phase
Starting from a mixture of Al-Cu-Fe quasicrystalline (QC) particles and Al powder, a fully dense and almost Al-Cu-Fe omega 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.