Internal Friction of Iron-Aluminium Alloys Containing Carbon

Abstract

In order to investigate effects of ordering on the Snoek peak of carbon in Fe–Al alloys, internal friction measurements have been carried out on alloys containing 0 to 30.0 at.% Al and about 0.01 wt.% C. A relaxation peak was found to occur at 130°C at the frequency of about 1 cps in the region between 19.3 and 24.5 at.% Al after appropriate heat-treatments, and it was attributed to stress-induced diffusion of carbon in ordered Fe₃Al lattice. Another peak occured at 160°C in the region between 25.1 and 30.0 at.% Al, but its origin was not so well clarified. A brief discussion is made concerning the relaxation mechanism of the 130°C-peak.