The Experts below are selected from a list of 6519 Experts worldwide ranked by ideXlab platform
Ruimei Yuan - One of the best experts on this subject based on the ideXlab platform.
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ablation resistance of hfb2 sic coating prepared by in situ reaction method for sic coated c c composites
Ceramics International, 2017Co-Authors: Peipei Wang, Hejun Li, Yulei Zhang, Ruimei YuanAbstract:Abstract To improve the ablation resistance of SiC coating, HfB 2 -SiC coating was prepared on SiC-coated carbon/carbon (C/C) composites by in-situ reaction method. Owing to the penetration of coating powders, there is no clear boundary between SiC coating and HfB 2 -SiC coating. After oxyacetylene ablation for 60 s at heat flux of 2400 kW/m 2 , the mass ablation rate and linear ablation rate of the coated C/C composites were only 0.147 mg/s and 0.267 µm/s, reduced by 21.8% and 60.0%, respectively, compared with SiC coated C/C composites. The good ablation resistance was attributed to the formation of multiple Hf-Si-O Glassy Layer including SiO 2 , HfO 2 and HfSiO 4 .
Zhong Lin Wang - One of the best experts on this subject based on the ideXlab platform.
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high temperature oxidation resistance of metal silicide incorporated zrb2 composite coatings prepared by vacuum plasma spray
Ceramics International, 2015Co-Authors: Zhong Lin Wang, Cui Hu, Hong Li, Yi Zeng, Xuebin ZhengAbstract:Abstract Metal silicides are often utilized to enhance high temperature oxidation resistance for refractory ZrB2 ceramics or coatings owing to the capability to form Glassy silica Layer. However, the role of metal elements in silicides on maintaining the Glassy Layer needs to be elucidated. In the present study, TaSi2 and MoSi2 incorporated ZrB2 composite coatings were respectively prepared by vacuum plasma spray (VPS) technology and their oxidation behaviors were comparatively investigated. The oxidation tests carried out in ambient air at 1773 K confirmed the crucial function of Glassy silica Layer on high temperature oxidation resistance for both of the metal silicide incorporated ZrB2 coatings. More importantly, the metal elements in silicide additives were revealed to have great influence on the integrity of Glassy silica Layer. The oxidation of element Ta in TaSi2 generated plate-like compound TaZr2.75O8, which impaired the consistency and completeness of silica Layer, creating opportunity for oxygen diffusion. However, MoB, the oxidation product of element Mo in MoSi2, could help supporting the integrity of silica Layer. MoB played the role defending the wholeness of silica Layer and reducing the evaporation of B2O3 and MoO3 at the same time. Better oxidation resistance of ZrB2–MoSi2 composite coating was found as compared with ZrB2–TaSi2 composite coating.
Peipei Wang - One of the best experts on this subject based on the ideXlab platform.
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ablation resistance of hfb2 sic coating prepared by in situ reaction method for sic coated c c composites
Ceramics International, 2017Co-Authors: Peipei Wang, Hejun Li, Yulei Zhang, Ruimei YuanAbstract:Abstract To improve the ablation resistance of SiC coating, HfB 2 -SiC coating was prepared on SiC-coated carbon/carbon (C/C) composites by in-situ reaction method. Owing to the penetration of coating powders, there is no clear boundary between SiC coating and HfB 2 -SiC coating. After oxyacetylene ablation for 60 s at heat flux of 2400 kW/m 2 , the mass ablation rate and linear ablation rate of the coated C/C composites were only 0.147 mg/s and 0.267 µm/s, reduced by 21.8% and 60.0%, respectively, compared with SiC coated C/C composites. The good ablation resistance was attributed to the formation of multiple Hf-Si-O Glassy Layer including SiO 2 , HfO 2 and HfSiO 4 .
Xuebin Zheng - One of the best experts on this subject based on the ideXlab platform.
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high temperature oxidation resistance of metal silicide incorporated zrb2 composite coatings prepared by vacuum plasma spray
Ceramics International, 2015Co-Authors: Zhong Lin Wang, Cui Hu, Hong Li, Yi Zeng, Xuebin ZhengAbstract:Abstract Metal silicides are often utilized to enhance high temperature oxidation resistance for refractory ZrB2 ceramics or coatings owing to the capability to form Glassy silica Layer. However, the role of metal elements in silicides on maintaining the Glassy Layer needs to be elucidated. In the present study, TaSi2 and MoSi2 incorporated ZrB2 composite coatings were respectively prepared by vacuum plasma spray (VPS) technology and their oxidation behaviors were comparatively investigated. The oxidation tests carried out in ambient air at 1773 K confirmed the crucial function of Glassy silica Layer on high temperature oxidation resistance for both of the metal silicide incorporated ZrB2 coatings. More importantly, the metal elements in silicide additives were revealed to have great influence on the integrity of Glassy silica Layer. The oxidation of element Ta in TaSi2 generated plate-like compound TaZr2.75O8, which impaired the consistency and completeness of silica Layer, creating opportunity for oxygen diffusion. However, MoB, the oxidation product of element Mo in MoSi2, could help supporting the integrity of silica Layer. MoB played the role defending the wholeness of silica Layer and reducing the evaporation of B2O3 and MoO3 at the same time. Better oxidation resistance of ZrB2–MoSi2 composite coating was found as compared with ZrB2–TaSi2 composite coating.
Narendra B Dahotre - One of the best experts on this subject based on the ideXlab platform.
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laser surface cladding of fe b c fe b si and fe bc si al c on plain carbon steel
Surface & Coatings Technology, 2006Co-Authors: I Manna, Dutta J Majumdar, Ramesh B Chandra, S Nayak, Narendra B DahotreAbstract:In the present study, an attempt has been made to explore deposition of Fe-based amorphous/Glassy Layer on a plain carbon (AISI 1010) steel by laser surface cladding (LSC) to improve resistance of the substrate to wear and corrosion. Three known glass forming powder blends (under rapid solidification condition) with nominal compositions of 94Fe4B2C, 75Fe15B10Si and 78Fe10BC9Si2Al1C (all in wt.%) were deposited by LSC using a continuous wave Nd:YAG laser under optimum processing conditions determined by preliminary trials. Following LSC, the microstructure and mechanical properties (microhardness and wear resistance) were evaluated in details. Despite the rapid quenching accompanying LSC, none of the coatings developed/retained amorphous/Glassy cladding possibly due to large-scale solute redistribution in the clad zone and/or between the clad Layer and substrate. The clad microstructure is characterized by fine dispersion of nano/microcrystalline intermetallic and interstitial compounds/phases in ferritic matrix. Both microhardness and wear resistance showed a significant improvement, particularly after LSC with 94Fe4B2C. Potentiodynamic polarization studies in 3.56 wt.% NaCl solution showed that corrosion resistance of the substrate was remarkably improved by LSC with 94Fe4B2C, but slightly deteriorated after LSC with the other two coatings. Thus, it appears that LSC with 94Fe4B2C, among the present coatings, significantly enhances hardness and resistance to wear and corrosion of the substrate, though fails to develop/retain amorphous microstructure under the present laser processing condition.