Third-type of Strain Aging of GH4720Li Over a Wide Range of Temperatures and Strain Rates

In this study, the working environment of the GH4720Li alloy was simulated using a dynamic compression test with a strain rate range of 0.01–4000 s-1 and a temperature range of 20–1000 °C, and its dynamic mechanical properties under operating conditions were studied. Based on the signifi cant volume of the test data, it was observed that there was an abnormal stress peak in the GH4720Li alloy owing to third strain aging. The third strain aging behavior is an irregular bell-shaped stress curve. In addition, the effects of the temperature and strain rate on the bell-shaped stress curve were studied. With an increase in the strain rate, the bell-shaped stress curve shifted to the high-temperature zone, and the stress peak and temperature width of the bell-shaped curve gradually decreased. Finally, the change mechanism of the strain rate effect on the bell-shaped stress curve is explained from a microscopic point of view.