A study of Fe-Al coating as transition layer on FeCrAl substrate by pack aluminizing.

• The process parameters of Fe-Al coating prepared on FeCrAl alloy were investigated. • The temperature-dependent growth kinetic equation of the Fe-Al coating is obtained. • The time-dependent growth kinetic equation of the e Fe-Al coating is obtained. • The permeation reduction factor of Fe-Al coating are 67 at 360 °C and 40 at 400 °C. Al 2 O 3 is a promising tritium permeation barrier coating material due to its excellent thermodynamic stability and tritium permeation resistance. However, the thermal mismatch between Al 2 O 3 and FeCrAl alloy will affect the coating performance. Fe-Al coating can act as a transition layer between the Al 2 O 3 coating and FeCrAl alloy which can reduce the difference in thermal expansion coefficient. The process parameters and coating properties of Fe-Al coating prepared on FeCrAl alloy by pack aluminizing have been investigated by energy dispersive spectrometer, scanning electron microscope, electron back scatter diffraction and deuterium permeation experiment. The Fe-Al coating is primarily composed of Fe 2 Al 5 phase. The growth kinetic equation of the Fe-Al coating under different aluminizing temperature below 700 °C and the growth kinetics equation of the Fe-Al coating under different aluminizing time were obtained. [ABSTRACT FROM AUTHOR]