Concentration Dependence of Internal Friction in AlMg Alloy

Abstract

An internal friction peak in a series of Al-Mg alloys containing up to 12.1 wtyo Mg has been studied at torsional frequencies in the range 0.4 to 98 Hz. The temperature a t which the maximum occurred was found to vary according to the Arrhenius equation with an activation energy of 1.4 eV. The peak height was found to be proportional to Cg, c "~~ where CAI and C M~ are the atomic concentrations of Al and Mg, respectively. The peak as measured after slow furnace cooling, at 0.4 Hz, was displaced to lower temperatures as a result of quenching. The magnitude of this displacement appeared to increase with increasing Mg concentration. -The results, coupled with those of complementary electron microscopy and X-ray lattice parameter studies, substantiate previous interpretation of the peak in

Low Frequency Relaxation Effect Observed in Al-Mg Alloy

“…In Al -7.5 wt % Mg alloy, Dey et al [1] described a Zener peak shifting to low temperatures after quenching and another weak peak more pronounced during ageing, attributed to the formation of GP zones. Belson et al [2] performed internal friction experiments in a series of Al-Mg alloys containing up to 12.1 wt % Mg. They confirmed the existence of a Zener peak.…”