Abstract
The internal friction or acoustic absorption peak (versus temperature) around 350°C previously observed in tantalum with a frequency of vibration of about one cycle per second was further analyzed. It is shown that this peak has its origin in the stress-induced interstitial diffusion of N in tantalum similar to the cases of C and O in tantalum reported before. The precipitation of N from the solid solution with tantalum was followed by internal friction measurements.