TY - JOUR
T1 - Corrosion behavior of Y2O3-doped mullite-ZrSiO4 coatings applied on C/C–SiC composites in the presence of moisture at temperatures of 1373–1773 K
AU - Qian, Tianxiao
AU - Zeng, Yi
AU - Xiong, Xiang
AU - Ye, Ziming
AU - Lun, Huilin
AU - Hu, Jinrun
AU - Wang, Yalei
AU - Zhang, Zhongwei
AU - Yan, Changhai
N1 - Publisher Copyright:
© 2020 Elsevier Ltd and Techna Group S.r.l.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - Commercial mullite powders show great potential for application in environmental barrier coatings. However, most of the commercial mullite powders contain amorphous silica, which produces volatile silicon hydroxide in hot steam. This leads to serious recession of mullite coatings in hot water vapor. In this study, a Y2O3-doped mullite-ZrSiO4 coating was fabricated on C/C–SiC composites using the slurry painting method. The addition of Y2O3 resulted in the elimination of the residual silica and derived-cristobalite in the commercial mullite powder, leading to the formation of a stable mullite-Y2Si2O7–ZrSiO4 coating. This indicates that Y2O3 can efficiently enhance the phase stability of commercial mullite at high temperatures. In addition, the corrosion behaviours of Y2O3-doped mullite-ZrSiO4 coatings were investigated at 1373, 1573, and 1773 K in a 95% H2O-5% O2 atmosphere. The coatings exhibited good corrosion resistance. The 15 mol% Y2O3 coating showed a weight loss rate of 1.62 wt % when exposed to hot steam for 10 h at 1573 K. This value is only 1/8th of that of the uncoated sample. Moreover, ZrSiO4 improved the water corrosion resistance of the Y2O3-doped mullite-ZrSiO4 coatings at 1573 K.
AB - Commercial mullite powders show great potential for application in environmental barrier coatings. However, most of the commercial mullite powders contain amorphous silica, which produces volatile silicon hydroxide in hot steam. This leads to serious recession of mullite coatings in hot water vapor. In this study, a Y2O3-doped mullite-ZrSiO4 coating was fabricated on C/C–SiC composites using the slurry painting method. The addition of Y2O3 resulted in the elimination of the residual silica and derived-cristobalite in the commercial mullite powder, leading to the formation of a stable mullite-Y2Si2O7–ZrSiO4 coating. This indicates that Y2O3 can efficiently enhance the phase stability of commercial mullite at high temperatures. In addition, the corrosion behaviours of Y2O3-doped mullite-ZrSiO4 coatings were investigated at 1373, 1573, and 1773 K in a 95% H2O-5% O2 atmosphere. The coatings exhibited good corrosion resistance. The 15 mol% Y2O3 coating showed a weight loss rate of 1.62 wt % when exposed to hot steam for 10 h at 1573 K. This value is only 1/8th of that of the uncoated sample. Moreover, ZrSiO4 improved the water corrosion resistance of the Y2O3-doped mullite-ZrSiO4 coatings at 1573 K.
KW - Commercial mullite
KW - Environmental barrier coating
KW - Mullite-YSiO–ZrSiO coating
KW - Water vapor corrosion behaviour
UR - http://www.scopus.com/inward/record.url?scp=85078442405&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2020.01.124
DO - 10.1016/j.ceramint.2020.01.124
M3 - Article
AN - SCOPUS:85078442405
SN - 0272-8842
VL - 46
SP - 12861
EP - 12869
JO - Ceramics International
JF - Ceramics International
IS - 8
ER -