Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (28권3호 152-163)

Kinetic Analysis of Diffusion Aluminide Coating

확산 알루미나이드 코팅의 속도론적 해석

손희식;김문일;
;;

국방과학연구소;연세대학교 공과대학 금속공학과;
국방과학연구소;연세대학교 공과대학 금속공학과;

Abstract

A theoretical model which combines gaseous transport and solid state diffusion with the multi-component equilibrium at the gas/pack and gas/coating interfaces was used to study the kinetics of diffusion aluminide coating. The diffusion aluminide coatings were applied by pack cementation with Ni substrate under argon atmosphere in the high activity and the low activity pack containing $NH_4CL$ or $AlF_3$ activator. On the basis of the process conditions, the suggested model allows the surface composition, the growth rate of coating layers and the aluminium concentration profiles in coatings to be calculated. In the case of $NH_4$Cl activator, careful consideration was required in the analysis, because activator contains nitrogen and hydrogen as well as halogen element to activate the pack. A good agreement is obtained between the theoretical predictions and the experimental results.

Keywords