Functionally multilayered Yb‐silicate EBCs fabricated using slurry spraying‐reactive sintering technique

Author:

Waghmare Gauri1,Hastak Vikram1,Gandhi Ashutosh S.1ORCID

Affiliation:

1. Department of Metallurgical Engineering and Materials Science Indian Institute of Technology Bombay Mumbai Maharashtra India

Abstract

AbstractFunctionally multilayered environmental barrier coatings (EBCs) with the desired layer sequence of Yb2O3/Yb2SiO5/Yb2Si2O7/SiO2/Si were obtained using an unconventional yet simple technique of reactive sintering. Yb2O3 slurry was sprayed on polycrystalline silicon (used as a bond coat for SiCf/SiC composites) and reactive sintered to generate graded layers that provide a combination of mitigated thermal expansion mismatch as well as silica activity. The Yb2O3‐terpineol slurry produced a uniform deposit of the Yb2O3 topcoat. Reactive sintering of exploratory coatings (∼ 10–20 µm) was carried out in air by varying the temperature (1100–1400°C) and time (2–24 h). X‐ray diffraction and scanning electron microscopy‐energy‐dispersive spectroscopy technique confirmed the in situ formation of X2‐Yb2SiO5 and β‐Yb2Si2O7. Rietveld refinement was performed to know the volume fractions of the respective phases. The set of process parameters identified from the preliminary work was employed to fabricate EBCs with thickness ∼ 250 µm. The X2‐Yb2SiO5 and β‐Yb2Si2O7 phases formed next to the Si/SiO2 interface as two separate layers. Post‐sintering heat treatments in air at 1300, 1350, and 1400°C for 3–50 h elucidated the growth characteristics of the oxide layers to be a function of both temperature and time. The theoretical considerations of diffusional reactive phase formation of the EBC multilayer growth rates are discussed.

Publisher

Wiley

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3