Formation and Growth Kinetic of Intermetallic Layers on 304SS at Different Slurry Aluminizing Temperature and Time Using Si‑Al2O3‑Modified Aluminide Coating
No Thumbnail Available
Date
2025-05-18
Journal Title
Journal ISSN
Volume Title
Publisher
Published by springer
Abstract
The study explored how the presence of silicon
(Si) and alumina influences the microstructures and growth
kinetics of intermetallic compounds within aluminide coatings
applied to 304 stainless steels. The aluminide coating
was prepared via slurry aluminizing techniques and heat
treated at 700 °C, 800 °C and 850 °C for 6, 8 and 10 h. The
aluminide coating was characterized using field emission
electron microscope-energy dispersive X-ray, X-ray diffraction
and hardness. Multilayer phases were formed which
comprise of binary phases (
Fe2Al5, FeAl3,
FeAl and Fe3Al),
and the Fe–Si–Al ternary phases (
Fe2Al3Si3, Fe4Al17.5Si1.5
and Fe4Al1.7Si).
As the aluminizing temperature and time
increase, the thickness of the brittle intermetallic layer
(
Fe2Al5) layer decreases, while the thickness of the ductile
intermetallic layers (FeAl and Fe3Al)
increases. The growth
rate of the layers obeyed a parabolic law. The activation
energy for Fe2Al5
was − 174 kJ/mol, while the activation
energy for FeAl and Fe3Al
were 72 kJ/mol and 155 kJ/mol
respectively. Microhardness measurement revealed that
Fe2Al5,
FeAl, and Fe3Al
layers had hardness values of 880–
1010 HV, 570–630 HV, and 320–410 HV respectively at all
aluminizing temperature and time. Fe2Al5
has the lowest
toughness and the hardest zone in the aluminide coating. The
Si addition effectively reduced the coating thickness of the
brittle intermetallic layers and aided the growth of ductile
intermetallic layers.
Description
Keywords
Slurry aluminizing · Si-Al2O3-modified aluminide coating · Intermetallic layer · 304SS · Growth kinetics · Hardness
Citation
Ambali, I. O., Anasyida, A. S., Abdullah, T. K., & Dhindaw, B. K.