Heat treatment effect on internal friction of cast nickel-chromium base alloy

The internal friction of a cast nickel-chrome-based alloy in the temperature range of 20-900 deg C after various heat treatment regimes was studued, taking into account certain relaxation phenomena. It was established that quenching from different temperatures, the cooling rate, and subsequent ageing change the temperature spectrum of internal friction. Pronounced internal friction maxima are observed at 180 deg C with an activation energy of 25+-2 kcal/g-atom for the alloy in the initial state, at 280 deg C with an activation energy of 30+-2 kcal/g-atom for the alloy water-quenched 1150 C, and 310 and 200 deg C for alloys air-quenched from 1200 deg C and 1250, respectively