Study on the microstructure and high-temperature oxidation resistance of
bentonite modified MoSi2-based composite coatings
ZHU Lu1,YIN Jinnan2,FENG Peizhong1
(1. School of Materials and Physics,China University of Mining and Technology,Xuzhou 221116,China; 2. Air
Force 93147 Chinese People’s Liberation Army,Chengdu 610000,China)
Abstract:The microstructural evolution and high-temperature oxidation behavior of bentonite modified MoSi2
composite coating prepared by spark plasma sintering were studied. The results show that the composite coating is
mainly composed of MoSi2 phase and a small amount of Mo5Si3 phase, and the addition of bentonite reduces the
CTE mismatch between the coating and substrate, thus the composite coating presents a crack-free morphology.
During oxidation at 1 500 ℃, the composite coating maintains slow mass gain since a dense and complete layer of
SiO
2 forms on the surface during the oxidation process, which inhibits the high-temperature diffusion of oxygen
and effectively avoids the further oxidation inside the coating. Compared with single MoSi2 coating, the oxide scale
of the bentonite modified composite coating is thinner with a crack-free morphology, therefore showing relatively
better high-temperature oxidation resistance