摘要

FeAl alloys of nominal Al content 28, 38 and 45 at.% and Fe28Al5Cr with minor alloying elements added to improve their application properties are studied by positron annihilation lifetime analysis. The lifetime spectra of samples FeXAl with X >= 38 (both quenched and cooled with furnace) are described by a single lifetime component related to the saturated positron trapping by quenched-in vacancies of concentration much higher than 100 ppm. A very strong dependence of retained vacancy concentration on the rate of cooling is shown for Fe28Al and Fe28Al5Cr alloys. After quenching, the concentration is of the order of 10(-4) whereas in samples slowly cooled it is reduced to 10(-5). The chromium addition to Fe28Al5Cr dismisses the vacancies concentration in comparison to the concentration in Fe28Al after the same heat treatment.

  • 出版日期2010