硅酸盐学报

Si₃N₄-SiC耐火材料制备中二硼化物微结构演变与致密化作用的关联

PDF下载

廉晓庆 ¹ , 曹会彦 ² , 王龙庆 ² , 李铁军 ¹ , 华小虎 ¹ , 邓丽荣 ¹

硅酸盐学报 | 研究论文 2025,53(11): 3372-3381

收起

硅酸盐学报 |研究论文 2025 , 53 (11) : 3372 -3381

Si₃N₄-SiC耐火材料制备中二硼化物微结构演变与致密化作用的关联

全屏

廉晓庆¹, 曹会彦², 王龙庆², 李铁军¹, 华小虎¹, 邓丽荣¹

作者信息

^1．西安科技大学材料科学与工程学院，西安 710054

^2．中钢集团洛阳耐火材料研究院有限公司，先进耐火材料全国重点实验室，河南洛阳 471039

作者简介:

廉晓庆（1985—），女，博士，讲师。

Relationship Between Microstructure Evolution and Densification Effects of Diboride Additives in Preparation Process of Si₃N₄-SiC Refractories

Xiaoqing LIAN¹, Huiyan CAO², Longqing Wang², Tiejun LI¹, Xiaohu HUA¹, Lirong DENG¹

Affiliations

^1.Collage of Materials Science and Engineering, Xi'an University of Science and Technology, Xi'an 710054, China

^2.State Key Laboratory of Advanced Refractories, Sinosteel Luoyang Institute of Refractories Research Co., Ltd., Luoyang 471039, Henan, China

LIAN Xiaoqing (1985-), female, Ph.D., Lecturer. E-mail: lianxiaoqing0304@126.com

出版时间: 2025-11-20 doi: 10.14062/j.issn.0454-5648.20250357

文章导航

摘要

收起

二硼化物是基于增强SiO分压促进Si₃N₄-SiC耐火材料致密化的新型添加剂，但其微结构演变与致密化作用的关联尚不明确。为建立二者关联性，在Si₃N₄-SiC耐火材料中引入TiB₂和AlB₂微粉，借助同步热分析仪、X射线衍射仪、扫描电子显微镜、透射电子显微镜等测试手段，研究不同种类二硼化物的氧化和氮化反应过程、微结构演变及其对Si₃N₄-SiC耐火材料的致密化作用。研究表明：添加适量TiB₂和AlB₂微粉均可改善Si₃N₄-SiC耐火材料致密性，减小Si₂N₂O相含量和α-Si₃N₄/β-Si₃N₄质量比，最优添加量均为0.6%；二硼化物的微结构演变通过影响Si氮化反应阶段的SiO分压和Si₃N₄晶须生长，来进一步影响致密化作用；一类二硼化物以TiB₂为代表，氧化产物间不发生进一步化学反应，形成玻璃相包裹结构，大部分留存至Si氮化反应阶段，可有效降低氧分压、增强SiO分压、促进Si间接氮化，生成大量直径约200 nm的β-Si₃N₄晶须并形成三维网络结构，致密化作用强；另一类硼化物以AlB₂为代表，因氧化产物发生反应，玻璃相包裹结构被破坏，相同添加量下致密化效果更弱。

关键词

氮化硅-碳化硅 / 二硼化钛 / 二硼化铝 / 一氧化硅分压 / 微结构演变 / 致密化

Abstract

收起

Introduction

Reaction-bonded Si₃N₄-SiC refractories are preferred thermally conductive materials for waste incinerators. However, their high apparent porosity limits their high-temperature wear resistance and resistance to water vapor oxidation. Promoting the growth of Si₃N₄ whiskers is an effective approach to improve the densification of Si₃N₄-SiC refractories. Related researches have mainly focused on catalytic nitridation to facilitate the direct nitridation reactions, while there are few studies on enhancing the partial pressure of SiO and promoting the indirect nitridation reactions. In addition to ultrafine silicon powders, diborides are new additives that can enhance the partial pressure of SiO and promote the densification of Si₃N₄-SiC refractories. Nevertheless, the relationship between their microstructure evolution and densification effects remains unclear. In this work, the phase composition and microstructure evolution of TiB₂ and AlB₂ micro-powders during the preparation process of Si₃N₄-SiC refractories were investigated, as well as their effects on the bulk density, apparent porosity, phase composition and microstructure of the refractories. This study is expected to enrich the nitridation mechanism system of silicon powders, and provide a theoretical basis for selecting densification additives for Si₃N₄-SiC refractories.

Methods

To investigate the oxidation and nitridation reactions of TiB₂ and AlB₂ micro-powders during the preparation process of Si₃N₄-SiC refractories, thermodynamic analysis of the Si-TiB₂-AlB₂-N₂-O₂ system was performed using HSC Chemistry software, and TG-DSC analysis in high purity N₂ atmosphere was conducted with a synchronous thermal analyzer. The phase composition and microstructure evolution of TiB₂ and AlB₂ micro-powders heat-treated at 1400 ℃ in high purity N₂ atmosphere were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Moreover, quantitative analysis of the phase composition was implemented via the K-value method. Reaction-bonded Si₃N₄-SiC refractories were prepared with TiB₂ and AlB₂ micro-powders as additives. The bulk density and apparent porosity of refractory samples were determined via the Archimedes drainage method. A universal testing machine was used to measure the compressive strength of the refractory samples at room temperature. XRD, SEM, EDS, and TEM were employed to analyze the phase composition and microstructure evolution of Si₃N₄-SiC refractories, with particular attention on the morphology, quantity, and distribution of Si₃N₄ whiskers. Based on the above mentioned analyses, the relationship between the microstructure evolution and densification effects of diboride additives was established.

Results and discussion

Thermodynamic analysis results show that the oxidation and nitridation activities of AlB₂ are slightly higher than those of TiB₂ and significantly higher than those of Si. According to TG-DSC analyses, the initial temperature of the nitridation reaction for TiB₂ is 150 ℃ higher than that of AlB₂, which is consistent with the thermodynamic analysis results. After heat treatment at 1400 ℃ in high purity N₂ atmosphere, over 60% of TiB₂ micro-powders remains unreacted and a glass phase surrounded structure can be observed. In contrast, the content of unreacted AlB₂ content is below 10%, and few glassy phases are observed. That's because B₂O₃ glassy phase has reacted with Al₂O₃ to form a new solid phase of Al₄B₂O₉. With an appropriate addtion, both TiB₂ and AlB₂ micro-powders improve the densification of Si₃N₄-SiC refractories, reduce the content of Si₂N₂O phase, and lower the ratio of α/β-Si₃N₄. The optimal addition amount for both additives is 0.6%. Under the same addition amount, TiB₂ exhibits a superior densification effect. When the TiB₂ addition amount is 0.6%, a large quantity of β-Si₃N₄ whiskers are generated, with an average diameter of approximately 200 nm and an aspect ratio exceeding 50. These whiskers entangle with each other to form a three-dimensional network structure, and their growth follows the gas-solid mechanism.

Conclusions

The microstructure evolution of diboride additives modulates the SiO partial pressure and Si₃N₄ whiskers growth during silicon powder nitridation, which in turn affects the densification of Si₃N₄-SiC refractories. For instance, the oxidation products of TiB₂ do not undergo further chemical reactions but instead form a protective glassy phase. This phase protects most TiB₂ from consumption until the nitridation reaction stage, thereby effectively reducing the partial pressure of O₂. Since the partial pressure of SiO in the SiO-N₂-O₂ system increases as the partial pressure of O₂ decreases, TiB₂ micro-powders are effective to enhance the partial pressure of SiO and promote the indirect nitridstion reactions, producing a large number of β-Si₃N₄ whiskers. Therefore, they are highly suitable as densification additives for Si₃N₄-SiC refractories.

Key words

silicon nitride-silicon carbide / titanium diboride / aluminum diboride / partial pressure of silicon monoxide / microstructure evolution / densification

引用本文

廉晓庆, 曹会彦, 王龙庆, 李铁军, 华小虎, 邓丽荣. Si₃N₄-SiC耐火材料制备中二硼化物微结构演变与致密化作用的关联. 硅酸盐学报, 2025 , 53 (11) : 3372 -3381 . DOI: 10.14062/j.issn.0454-5648.20250357

Xiaoqing LIAN, Huiyan CAO, Longqing Wang, Tiejun LI, Xiaohu HUA, Lirong DENG. Relationship Between Microstructure Evolution and Densification Effects of Diboride Additives in Preparation Process of Si₃N₄-SiC Refractories[J]. Journal of the Chinese Ceramic Society, 2025 , 53 (11) : 3372 -3381 . DOI: 10.14062/j.issn.0454-5648.20250357

基金

收起

宁夏回族自治区重点研发计划(2022BFEO1003)

参考文献

收起

文献

收起

参考文献引证文献

排序方式：

2025年第53卷第11期

PDF下载

引用本文

BibTeX

文章信息

doi: 10.14062/j.issn.0454-5648.20250357

接收时间：2025-05-04
首发时间：2026-10-21
出版时间：2025-11-20

补充材料

相关文章

文章信息

作者

出版历史

收稿日期：2025-05-04
修回日期：2025-05-28

基金

宁夏回族自治区重点研发计划(2022BFEO1003)

作者信息

^1．西安科技大学材料科学与工程学院，西安 710054

^2．中钢集团洛阳耐火材料研究院有限公司，先进耐火材料全国重点实验室，河南洛阳 471039

参考文献

分享链接

https://castjournals.cast.org.cn/joweb/gsyxb/CN/10.14062/j.issn.0454-5648.20250357

分享至

全文二维码

扫描看全文

引用本文

BibTeX

本文的引用情况

2种不同金属材料的力学参数

科 Family	属数 Number of genus	种数 Number of species	占总种数比例 Percentage of total species (%)	属 Genus	种数 Number of species	占总种数比例 Percentage of total species (%)
鹅膏菌科Amanitaceae	2	11	5.26	鹅膏菌属 Amanita	10	4.78
小菇科 Mycenaceae	2	12	5.74	丝盖伞属 Inocybe	5	2.39
多孔菌科 Polyporaceae	8	14	6.70	蜡蘑属 Laccaria	5	2.39
红菇科 Russulaceae	3	23	11.00	小皮伞属 Marasmius	6	2.87
				小菇属 Mycena	11	5.26
				光柄菇属 Pluteus	5	2.39
				红菇属 Russula	17	8.13
				栓菌属 Trametes	5	2.39

关闭全屏

BibTeX
EndNote
RefWorks
TxT