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Indexed by:期刊论文

Date of Publication:2018-04-18

Journal:JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY

Included Journals:SCIE、Scopus

Volume:32

Issue:8

Page Number:801-815

ISSN No.:0169-4243

Key Words:Plasma spraying; heat treatment; elastic modulus; fracture toughness

Abstract:Plasma sprayed NiCrAl/Al2O3-13wt.%TiO2 coating was fabricated and annealed at 300-900 degrees C in air atmosphere. The Elastic modulus (E), micro-hardness (H-V) and fracture toughness (K-ca) were evaluated by Vickers Indentation Fracture technique. The microstructure was studied by scanning electron microscopy. It can be concluded that with the increasing of annealing temperature, E and H-V at the interface of Substrate/Bond layer (S/B) are firstly increased and retain the highest value at 600 degrees C then decreased with higher annealing temperatures due to the phase transformation. E of the ceramic coating rised initially with annealing temperature increasing, reached the highest value at 400 degrees C, and then decreased with the further increasing of the temperature. The K-ca of the S/B interface firstly increased as the heating temperature increasing, confirming the crack initiation resistance increasing after annealing with the temperature below 700 degrees C. However, the K-ca decreased for further annealing temperature, even lower than that of the as-sprayed coating. Thereby, a proper annealing temperature can improve the mechanical properties of the coating since the coating becomes denser, ceramic lamellar structure becomes ambiguous and cracks are partially healed.