文章信息/Info

Title:

Thermal Protections and Silicide Coatings on Niobium Alloy

作者:

孫佳1; 王玉2; 付前剛1

（1. 西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，陜西 西安 710072) (2. 西安工程大學(xué)紡織與材料學(xué)院，陜西 西安 710048）

Author(s):

SUN Jia1;  WANG Yu2;  FU Qiangang1

(1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical Univeristy, Xi�餫n 710072, China)

（2. School of Textiles and Materials, Xi�餫n Polytechnic University, Xi�餫n 710048, China)

關(guān)鍵詞:

鈮合金; 硅化物; 涂層; 制備技術(shù); 抗氧化性能

Keywords:

Nb based alloy;  silicide;  coating;  preparation;  oxidation resistance

DOI:

10.7502/j.issn.1674-3962.2018.10.09

文獻(xiàn)標(biāo)志碼:

A

摘要:

鈮及其合金具有熔點(diǎn)高、密度適中、易焊接、高溫強(qiáng)度和可加工性能良好等特點(diǎn)，被認(rèn)為是理想的應(yīng)用在1200~1500 ℃高溫結(jié)構(gòu)熱端部件的候選材料，但其較弱的抗氧化性能是工程化應(yīng)用的瓶頸。綜述了鈮及其合金的高溫氧化特點(diǎn)和熱防護(hù)方法，指出涂層方法是鈮及其合金走向工程化應(yīng)用的關(guān)鍵。介紹了近年來應(yīng)用于鈮及其合金表面的抗氧化涂層體系，其中硅化物涂層熱防護(hù)體系因其表面能形成分布均勻、組織穩(wěn)定且熱擴(kuò)散速率低的硅酸鹽玻璃而抗氧化性能優(yōu)異。總結(jié)了硅化物涂層的主要制備方法和組織特點(diǎn)，并對所得涂層的抗氧化性能進(jìn)行了分析對比，指出抗氧化硅化物涂層的制備技術(shù)復(fù)合化是未來發(fā)展的方向。抑制硅化物涂層與鈮及其合金基體的反應(yīng)互擴(kuò)散，進(jìn)一步提高抗氧化硅化物涂層的使用溫度，增加涂層的隔熱性能、降低涂層的熱發(fā)射率是未來亟待解決的問題。

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�瞔omponents widely applied in high temperature range of 1200~1500 ℃. Unfortunately, the weak oxidation resistance severely restricts their engineering applications especially in the oxygen�瞔ontaining environment. In present paper, oxidation behaviors and thermal protection approaches of niobium�瞓ased alloys in high�瞭emperature oxygen�瞔ontaining environment are reviewed. It points out that the coating technique is the significant method to promote the high�瞭emperature application of niobium�瞓ased alloys to prevent oxygen penetration. The anti�瞣xidation coating systems built on the niobium�瞓ased 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�瞫table, homogeneously phase�瞕istributed 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�瞫intering, 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�瞙igh temperature anti�瞣xidation 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�瞓ased 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.