TY - JOUR
T1 - Enhanced sulphidation/oxidation resistance of Ti-45Al-8Nb alloy by multilayered coatings at 850 degrees C for up to 675 h
AU - Dudziak, T
AU - Du, HL
AU - Datta, PK
AU - Ehiasarian, AP
AU - Reinhard, C
AU - Hovsepian, PE
PY - 2014/10
Y1 - 2014/10
N2 - The high temperature sulphidation/oxidation behaviour of three multilayered coatings CrAlYN/CrN etched by Y+, CrAlYN/CrN etched by Cr+ and CrAlYN/CrN etched CrAl+ and the uncoated γ-TiAl (Ti–45Al–8Nb (at-%) used as reference sample was studied at 850°C for 675 h. Sulphidation/oxidation test was performed in the environment of H2/H2S/H2O, yielding pS2 = 10−1 Pa and pO2 = 10−18 Pa. Kinetic data obtained by discontinuous gravimetric method showed that the multilayered coatings effectively enhanced the sulphidation/oxidation resistance of γ-TiAl alloy. The corrosion resistance decreasing in order: CrAlYN/CrN etched by Y+>CrAlYN/CrN etched by CrAl+>CrAlYN/CrN etched by Cr+>γ-TiAl. Scale development studies using SEM, EDX and X-ray diffraction confirmed two regions of the coated materials: ‘affected,’ where coating cracked and developed non-protective TiO2 scale, and ‘unaffected,’ where protective (Al,Cr)2O3 scale formed. The uncoated γ-TiAl material, after exposure, showed a typical multilayered structure consisting of layers of TiO2 and Al2O3.
AB - The high temperature sulphidation/oxidation behaviour of three multilayered coatings CrAlYN/CrN etched by Y+, CrAlYN/CrN etched by Cr+ and CrAlYN/CrN etched CrAl+ and the uncoated γ-TiAl (Ti–45Al–8Nb (at-%) used as reference sample was studied at 850°C for 675 h. Sulphidation/oxidation test was performed in the environment of H2/H2S/H2O, yielding pS2 = 10−1 Pa and pO2 = 10−18 Pa. Kinetic data obtained by discontinuous gravimetric method showed that the multilayered coatings effectively enhanced the sulphidation/oxidation resistance of γ-TiAl alloy. The corrosion resistance decreasing in order: CrAlYN/CrN etched by Y+>CrAlYN/CrN etched by CrAl+>CrAlYN/CrN etched by Cr+>γ-TiAl. Scale development studies using SEM, EDX and X-ray diffraction confirmed two regions of the coated materials: ‘affected,’ where coating cracked and developed non-protective TiO2 scale, and ‘unaffected,’ where protective (Al,Cr)2O3 scale formed. The uncoated γ-TiAl material, after exposure, showed a typical multilayered structure consisting of layers of TiO2 and Al2O3.
KW - High temperature corrosion
KW - Multilayered coating
KW - Oxidation
KW - Sulphidation
KW - Gamma-TiAl
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=pure_starter&SrcAuth=WosAPI&KeyUT=WOS:000346129600001&DestLinkType=FullRecord&DestApp=WOS
U2 - 10.1179/1743278213Y.0000000142
DO - 10.1179/1743278213Y.0000000142
M3 - Article
SN - 1478-422X
VL - 49
SP - 590
EP - 602
JO - Corrosion Engineering Science and Technology
JF - Corrosion Engineering Science and Technology
IS - 7
ER -