Different oxidation protection mechanisms of HAPC silicide coating on niobium alloy over a large temperature range

Jia Sun; Tao Li; Guang Peng Zhang; Qian Gang Fu

doi:10.1016/j.jallcom.2019.03.229

Different oxidation protection mechanisms of HAPC silicide coating on niobium alloy over a large temperature range

Jia Sun, Tao Li, Guang Peng Zhang, Qian Gang Fu

School of Materials Sience and Engineering

Research output: Contribution to journal › Article › peer-review

32 Scopus citations

Abstract

Oxidation behaviors of halide activated pack cementation (HAPC) silicide coatings on niobium alloy were elaborately studied by experimental and theoretical analysis. The HAPC process was performed with a commonly applied powder pack of Si, NH₄F, and Al₂O₃ filler. Adsorptive Al₂O₃ particles from the pack from HAPC process played a positive role against oxidation at 700 °C (the so-called pest temperature). Above this temperature, the passion behavior rather than pulverization gradually appeared by the occurrence of seal-healing SiO₂. However, the seal-healing effect was meanwhile weakened by the generation of the volatilized Si-O (g) species when the temperature rose up to the eutectic point of Nb₂O₅-SiO₂ system. Continuously temperature-elevated (1500–1700 °C) oxidation overwhelmingly destroyed the surface protective scale by the depletion of melting Nb₂O₅ and the volatilization of SiO₂ (g), leading to a catastrophic failure of structural integrity for the coated samples.

Original language	English
Pages (from-to)	1014-1022
Number of pages	9
Journal	Journal of Alloys and Compounds
Volume	790
DOIs	https://doi.org/10.1016/j.jallcom.2019.03.229
State	Published - 25 Jun 2019

Keywords

Halide activation pack cementation
Niobium alloy
Oxidation
Silicide coating

Access to Document

10.1016/j.jallcom.2019.03.229

Cite this

@article{630a8aa0de0a4fb09695889316c52089,

title = "Different oxidation protection mechanisms of HAPC silicide coating on niobium alloy over a large temperature range",

abstract = "Oxidation behaviors of halide activated pack cementation (HAPC) silicide coatings on niobium alloy were elaborately studied by experimental and theoretical analysis. The HAPC process was performed with a commonly applied powder pack of Si, NH4F, and Al2O3 filler. Adsorptive Al2O3 particles from the pack from HAPC process played a positive role against oxidation at 700 °C (the so-called pest temperature). Above this temperature, the passion behavior rather than pulverization gradually appeared by the occurrence of seal-healing SiO2. However, the seal-healing effect was meanwhile weakened by the generation of the volatilized Si-O (g) species when the temperature rose up to the eutectic point of Nb2O5-SiO2 system. Continuously temperature-elevated (1500–1700 °C) oxidation overwhelmingly destroyed the surface protective scale by the depletion of melting Nb2O5 and the volatilization of SiO2 (g), leading to a catastrophic failure of structural integrity for the coated samples.",

keywords = "Halide activation pack cementation, Niobium alloy, Oxidation, Silicide coating",

author = "Jia Sun and Tao Li and Zhang, {Guang Peng} and Fu, {Qian Gang}",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = jun,

day = "25",

doi = "10.1016/j.jallcom.2019.03.229",

language = "英语",

volume = "790",

pages = "1014--1022",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - Different oxidation protection mechanisms of HAPC silicide coating on niobium alloy over a large temperature range

AU - Sun, Jia

AU - Li, Tao

AU - Zhang, Guang Peng

AU - Fu, Qian Gang

PY - 2019/6/25

Y1 - 2019/6/25

N2 - Oxidation behaviors of halide activated pack cementation (HAPC) silicide coatings on niobium alloy were elaborately studied by experimental and theoretical analysis. The HAPC process was performed with a commonly applied powder pack of Si, NH4F, and Al2O3 filler. Adsorptive Al2O3 particles from the pack from HAPC process played a positive role against oxidation at 700 °C (the so-called pest temperature). Above this temperature, the passion behavior rather than pulverization gradually appeared by the occurrence of seal-healing SiO2. However, the seal-healing effect was meanwhile weakened by the generation of the volatilized Si-O (g) species when the temperature rose up to the eutectic point of Nb2O5-SiO2 system. Continuously temperature-elevated (1500–1700 °C) oxidation overwhelmingly destroyed the surface protective scale by the depletion of melting Nb2O5 and the volatilization of SiO2 (g), leading to a catastrophic failure of structural integrity for the coated samples.

AB - Oxidation behaviors of halide activated pack cementation (HAPC) silicide coatings on niobium alloy were elaborately studied by experimental and theoretical analysis. The HAPC process was performed with a commonly applied powder pack of Si, NH4F, and Al2O3 filler. Adsorptive Al2O3 particles from the pack from HAPC process played a positive role against oxidation at 700 °C (the so-called pest temperature). Above this temperature, the passion behavior rather than pulverization gradually appeared by the occurrence of seal-healing SiO2. However, the seal-healing effect was meanwhile weakened by the generation of the volatilized Si-O (g) species when the temperature rose up to the eutectic point of Nb2O5-SiO2 system. Continuously temperature-elevated (1500–1700 °C) oxidation overwhelmingly destroyed the surface protective scale by the depletion of melting Nb2O5 and the volatilization of SiO2 (g), leading to a catastrophic failure of structural integrity for the coated samples.

KW - Halide activation pack cementation

KW - Niobium alloy

KW - Oxidation

KW - Silicide coating

UR - http://www.scopus.com/inward/record.url?scp=85063287844&partnerID=8YFLogxK

U2 - 10.1016/j.jallcom.2019.03.229

DO - 10.1016/j.jallcom.2019.03.229

M3 - 文章

AN - SCOPUS:85063287844

SN - 0925-8388

VL - 790

SP - 1014

EP - 1022

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

ER -

Different oxidation protection mechanisms of HAPC silicide coating on niobium alloy over a large temperature range

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this