Open AccessFormation of alumina-aluminide coatings on ferritic-martensitic T91 steel
Author(s) -
R. K. Choudhary,
Vivekanand Kain,
R.C. Hubli
Publication year - 2014
Publication title -
journal of mining and metallurgy. section b, metallurgy/journal of mining and metallurgy. section b, metallurgy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.42
H-Index - 20
eISSN - 2217-7175
pISSN - 1450-5339
DOI - 10.2298/jmmb140724022c
Subject(s) - aluminide , materials science , coating , metallurgy , amorphous solid , martensitic stainless steel , aluminium , substrate (aquarium) , composite material , martensite , intermetallic , microstructure , alloy , chemistry , oceanography , organic chemistry , geology
In this work, alumina-aluminide coatings were formed on ferritic-martensitic T91 steel substrate. First, coatings of aluminum were deposited electrochemically on T91 steel in a room temperature AlCl3-1-ethyl-3-methyl imidazolium chloride ionic liquid, then the obtained coating was subjected to a two stage heat treatment procedure consisting of prolonged heat treatment of the sample in vacuum at 300 ○C followed by oxidative heat treatment in air at 650 ○C for 16 hours. X-ray diffraction measurement of the oxidatively heat treated samples indicated formation of Fe-Al and Cr-Al intermetallics and presence of amorphous alumina. Energy dispersive X-ray spectroscopy measurement confirmed 50 wt- % O in the oxidized coating. Microscratch adhesion test conducted on alumina-aluminide coating formed on T91 steel substrate showed no major adhesive detachment up to 20 N loads. However, adhesive failure was observed at a few discrete points on the coating along the scratch track