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.com
Volume 5, Issue 5
Res. Rev. J Mat. Sci. 2017
ISSN: 2321-6212
Advanced Materials 2017
September 07-08, 2017
September 07-08, 2017 | Edinburgh, Scotland
Advanced materials & Processing
11
th
International Conference on
Hafnium and palladium modified aluminide coatings
Jolanta Romanowska
and
Maryana Zagula-Yavorska
Rzeszów University of Technology, Poland
H
afnium or palladium modification of NiAl phase increases the oxidation resistance of aluminide coatings deposited on turbine
blades in a hot section of jet engines. Small hafnium or palladium addition to aluminide coatings decreases the oxidation rate of
turbine blades made of nickel superalloys. Small content of hafnium (0.1-1.0 % wt) improves high temperature mechanical properties
of aluminized nickel based superalloys. Palladium modification increased the outer zone hardness. It is due to the presence of the σ
and µ phases. The palladium or hafnium modified aluminide coatings have better oxidation resistance than the non-modified ones.
The use of ‘co-doping’ has recently been emphasized as a strategy for optimizing the oxidation resistance of superalloys, conventional
alloys and coatings The comparison of structures of hafnium and palladium modified aluminide coatings deposited on pure nickel
and CMSX
4
nickel superalloy is presented. Aluminide layers were deposited by the Chemical vapor deposition (CVD) method.
Hafnium was deposited simultaneously with aluminum. Aluminum was deposited from the AlCl
3
and hafnium from the HfCl
3
gas
phases. Palladiumwas deposited by the electrodeposition method. The obtained coatings were examined using an optical microscope,
a scanning electron microscope and an XRD phase analyzer. Both coatings consist of two layers; an outer, comprising the ß-NiAl
phase and the interdiffusion one. The interdiffusion layer on pure nickel consists of the γ’-Ni
3
Al phase, whereas on the CMSX
4
– of the
ß-NiAl phase. Small inclusions of Pd and Hf rich phases were found at the border of the layers on nickel, whereas inclusion containing
Pd, Hf and refractory elements were observed in the interdiffusion zone on the CMSX
4
superalloy. The research has been supported
by the National Science Centre, Poland Grant No. 2015/19/B/ST8/01645.
Biography
Jolanta Romanowska has completed her PhD from AGH University of Science and Technology, Cracow, Poland and DSC from the Silesian University of
Technology, Poland. She is the professor at the Rzeszów University of Technology, Poland. She has published more than 50 papers in reputed journals. She has
her expertise in thermodynamics of alloys and protective coatings. She elaborated the model of predicting thermodynamic properties of ternary alloys on the basis
of thermodynamic properties of binary alloys.
jroman@prz.edu.plJolanta Romanowska et al., Res. Rev. J Mat. Sci. 2017, 5:5
DOI: 10.4172/2321-6212-C1-005
Fig.1:
Cross-section microstructure of aluminide
coating obtained by CVD method on pure nickel
(a), and CMSX4 nickel superalloy (b)