Temperature dependence of dynamic elastic moduli of wrought aluminum alloys

Abstract

Temperature dependence of dynamic elastic moduli of wrought aluminum alloys was studied by a resonant frequency method and the measured dynamic moduli were compared with the moduli determined by an ultrasonic method, reported in the previous paper. It was found that the elastic moduli weakly and linearly depended on the temperature below 250°C and that they decreased intensely with increasing temperatures above 250°C. Temperature dependence of the elastic moduli was nearly same for all the tested alloys within an experimental error. In terms of elastic moduli at room temperature, wrought aluminum alloys were classified into the following three groups: high strength alloys such as 2024-T4, 2024-0 and 2017-T4 with Young's modulus of (7.167.39)×105kg/cm2, such alloys as 2011 and 5052-0 with smaller Young's modulus of (6.546.17)×105kg/cm2 and such alloys as 2017-0, 5056-0 and 1100-0 with intermediate Young's modulus. A very close agreement between the modulus determined by a resonant method and that determined by an ultrasonic method was found for 2017-0, 2024-T4 and some other alloys. However, 2011-T3 and 2017-T4 alloys showed a difference between the moduli determined by the above two methods. This was considered due to the difference of measurement principles and of hypotheses or assumptions involved in calculations. This conclusion, therefore, suggests that elastic moduli should be reported with a clear indication of a measuring method.