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Thermal Protections and Silicide Coatings on Niobium Alloy(PDF)

MATERIALS CHINA[ISSN:1674-3962/CN:61-1473/TG]

Issue:
2018年第10期
Page:
51-55
Research Field:
特约研究论文
Publishing date:

Info

Title:
Thermal Protections and Silicide Coatings on Niobium Alloy
Author(s):
SUN Jia1 WANG Yu2 FU Qiangang1
(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical Univeristy, Xian 710072, China)
(2. School of Textiles and Materials, Xian Polytechnic University, Xian 710048, China)
Keywords:
Nb based alloy silicide coating preparation oxidation resistance
CLC:

PACS:
-
DOI:
10.7502/j.issn.1674-3962.2018.10.09
DocumentCode:

Abstract:
Niobium and its alloys have high melting point, moderate density, excellent weldability and high temperature strength as well as good machinability, and are considered as ideal candidates for hotcomponents widely applied in high temperature range of 1200~1500 ℃. Unfortunately, the weak oxidation resistance severely restricts their engineering applications especially in the oxygencontaining environment. In present paper, oxidation behaviors and thermal protection approaches of niobiumbased alloys in hightemperature oxygencontaining environment are reviewed. It points out that the coating technique is the significant method to promote the hightemperature application of niobiumbased alloys to prevent oxygen penetration. The antioxidation coating systems built on the niobiumbased alloys are introduced according to the variety of coating techniques. Silicide coating, which exhibits the best oxidation resistance among all coating systems, has attracted great interests due to its advantages of generating a thermalstable, homogeneously phasedistributed and low oxygen penetration rate silicate glass on the surface. Different preparation methods and microstructure characteristics of the silicide coatings are mainly illustrated, such as the slurrysintering, halide activated pack cementation, spark plasma sintering and thermal spray, meanwhile the oxidation resistance of the obtained silicide coatings has been comparatively analyzed. The combined preparation technology is seen as an efficient way to deposit ultrahigh temperature antioxidation silicide coating for future development although it still now presents complicated process and numerous influencing factors. Suppressing mutual elemental diffusion between the silicide coating and niobiumbased alloy matrix, further increasing the operation temperature, improving the thermal insulation performance and lowering the thermal emissivity of silicide coatings are the important scientific issues to be solved in the future.


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Last Update: 2018-11-12