耐火材料 ›› 2024, Vol. 58 ›› Issue (4): 277-283.DOI: 10.3969/j.issn.1001-1935.2024.04.001

• 研究开发 •    下一篇

Ti-Si-Fe合金添加量对Si3N4结合SiC材料结构与性能的影响

姚路炎, 韩兵强, 张锦化, 柯昌明   

  1. 武汉科技大学 省部共建耐火材料与冶金国家重点实验室 湖北武汉 430081
  • 收稿日期:2023-10-20 出版日期:2024-08-15 发布日期:2024-08-21
  • 通讯作者: 韩兵强,男,1973年生,博士,教授。E-mail:hbqref@wust.edu.cn
  • 作者简介:姚路炎:女,1992年生,博士研究生。E-mail:735611256@qq.com
  • 基金资助:
    科技部十二五支撑计划资助项目(2011BAB05B05);省部共建耐火材料与冶金国家重点实验室青年基金资助项目(2018QN11)。

Effect of Ti-Si-Fe alloy addition on structure and properties of Si3N4 bonded SiC refractories

Yao Luyan, Han Bingqiang, Zhang Jinhua, Ke Changming   

  1. First author's address: The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China
  • Received:2023-10-20 Online:2024-08-15 Published:2024-08-21

摘要: 为促进Si3N4结合SiC耐火材料的致密化,降低Si粉氮化温度,以SiC颗粒和细粉、Si粉为主要原料,利用从高钛型高炉渣提取的Ti-Si-Fe合金部分取代Si粉,在埋碳气氛下于1 350 ℃反应烧结5 h,制备了Si3N4结合SiC耐火材料。研究了Ti-Si-Fe合金添加量(加入质量分数分别为0、1.8%、3.6%、5.4%、7.2%)对Si粉的氮化行为、材料力学性能和显微结构的影响,并探讨了氮化反应烧结机制。结果表明:1)随着Ti-Si-Fe合金添加量的增加,材料的常温力学性能和高温抗折强度明显改善,荷重软化温度均超过1 700 ℃,Ti-Si-Fe合金添加量超过3.6%(w)后材料性能的增幅变缓;2)Ti-Si-Fe合金促进了Si粉在较低温度下的完全氮化和材料的反应烧结,Ti-Si-Fe合金中各物相及Si粉氮化反应的体积增加能够充填气孔,氮化产物改善骨料与基质、基质内部的结合状态,从而提高材料的致密化程度,改善力学性能;3)引入Ti-Si-Fe合金后,反应体系中形成了富含Ti、Si、N、Fe成分的液相,氮化物的形成除传统的VS、VLS机制外,溶解-沉淀机制在短柱状β-Si3N4、粒状TiN的形成中起到主导作用,交错连结的α-Si3N4晶须、短柱状β-Si3N4、粒状TiN对材料的力学性能起到增强作用。

关键词: Ti-Si-Fe合金, 反应烧结, Si3N4结合SiC耐火材料, 致密化, 溶解-沉淀

Abstract: In order to improve the densification of Si3N4 bonded SiC refractories and reduce the nitriding temperature of Si powder,Si3N4-bonded SiC refractories were produced by reaction sintering at 1 350 ℃ for 5 h under an carbon embedded atmosphere,using SiC particles and fine powder,and Si power as the main raw materials,and introducing Ti-Si-Fe alloy extracted from high-titanium blast furnace slag to partially replace the Si powder.The effects of the Ti-Si-Fe alloy addition (0,1.8%,3.6%,5.4% and 7.2%,by mass) on the nitriding behavior of Si powder,as well as the mechanical properties and microstructure of the material were investigated,and the nitriding reaction sintering mechanism was also explored.The results show that:(1)with the increase of the Ti-Si-Fe alloy addition,the cold mechanical properties and the hot modulus of rupture of the refractories are obviously improved,and the refractoriness under load exceeds 1 700 ℃;the property enhancement is slowed down with Ti-Si-Fe alloys addition above 3.6%;(2)Ti-Si-Fe alloy promotes the complete nitridation of Si powder and the reaction sintering of the material at a lower temperature;the volume growth during the nitridation process of the Ti-Si-Fe alloys and Si powder can effectively fill pores,nitriding products improve the bonding state between aggregates and matrix,and that inside matrix,thereby increasing the densification and improving the mechanical properties of the material;(3)after the introduction of Ti-Si-Fe alloys,the liquid phase rich in Ti,Si,N,and Fe components is formed in the reaction system;besides the traditional VS and VLS mechanisms,the dissolution-precipitation mechanism plays a leading role in the formation of short columnar β-Si3N4 and granular TiN;the cross-linked α-Si3N4 whiskers,short columnar β-Si3N4 and granular TiN enhance the mechanical properties of the material.

Key words: Ti-Si-Fe alloy, reaction sintering, Si3N4 bonded SiC refractories, densification, dissolution-precipitation

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