Recording Equipment for Measurements of Internal Friction and Elastic Modulus of Metals at Low Frequencies

A new equipment for measurements of internal friction and elastic modulus at low frequencies is described. The strain amplitude of specimen is relatively low, namely, of the order of 10^, and the upper limiting frequency is about 10 c/s. CdS photocells are used to detect torsional oscillations and an electromechanical driving system is adopted to excite and stop torsional vibrations. Several important points for practical operations such as the elimination of external disturbances are briefly mentioned. As an example of application, a result of internal friction and elastic modulus measurements on a cold-worked specimen of Cu-0.083 at. % Ag alloy is presented