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| Abstract No.: |
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Scheduled at:
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Tuesday, May 04, 2010, Sophia Room 10:40 AM
Properties 1
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| Title: |
Influence of substrate temperature on the microstructures and properties of APS Al2O3 coatings
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| Authors: |
Chang-Jiu Li* / Xi'an Jiaotong University, P.R. China
Shun Hao / School of Materials Science and Engineering, Xi'an Jiaotong University, P.R.China
Guan-Jun Yang/ School of Materials Science and Engineering, Xi'an Jiaotong University, P.R.China
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| Abstract: |
Thermally sprayed ceramic coatings exhibit a lamellar structure with a limited interface bonding. Surface temperature of the coating during coating builtup influences significantly the bonding formation at splat interfaces. It would be an effective approach to improve the interface bonding of the ceramic deposits through controlling substrate temperature during coating deposition.
In the present study, Al2O3 coatings were deposited by the atmospheric plasma spraying at different substrate temperatures of about 100, 275, 375, 480, 530 and 660??. The substrate surface temperature was monitored by an infrared pyrometer. The fractured cross-section microstructures were characterized by SEM. X-ray diffraction was used to analysis the phase compositions. Thermal conductivity, micro-hardness, Young?fs modulus and fracture toughness of the deposits were measured. The results show that columnar grains bonded across adjacent individual splats increase with the increase of the substrate surface temperature. Moreover, the thermal conductivity, micro-hardness, Young?fs modulus and fracture toughness increase with the increase of the substrate temperatures. The changes of coating properties are related to increase of lamellar bonding ratio in the deposits with the change of substrate temperature.
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