摘要
本文从反应机理、Al_(2)O_(3)–C界面改善技术、高比表面积前驱体制备技术以及反应气氛调控技术诸方面综述了碳热还原氮化(CRN)法合成氮化铝(AlN)粉体的研究进展。依据相关气-固反应讨论了反应过程的质量损失和晶须生长的传质过程,并根据固–固反应控制机理讨论了合成产物与前驱体形貌延续的现象,以及多项研究中Al–O–C与Al–C–N等Al_(2)O_(3)的转化中间态化合物的形成机制。在固–固反应机理中,C原子因其既能获得电子也能失去电子的性质而充当电子交换媒介促进N2分解和反应正向进行。采用CRN法合成氮化铝粉体技术工艺可归结为:1)通过引入有机高分子分散剂改善C与Al_(2)O_(3)颗粒的分散态,以形成在原料颗粒尺度层面上的均匀结合界面;2)通过引入黏结剂(如有机碳源)对Al_(2)O_(3)颗粒均匀包覆,并经热解形成裂解碳与Al_(2)O_(3)的均匀结合;3)通过有机物分解、燃烧合成、溶胶–凝胶和发泡–注凝等工艺技术实现多孔高比表面积前驱体的制备和铝源与碳源在超微尺度上的均匀混合,进而降低完全反应的条件,以合成纳米AlN粉体;4)增加反应气氛的置换(流动)效率,降低CO分压并增加N_(2)分压以促进合成反应的正向进行。根据现有研究成果,本文还以关键技术与关键装备结合为思路,分别提出发展连续式前驱体制造与连续式高温合成装备,尤其可解决温区差异和气流场差异问题的连续式高温合成装备,以提高CRN法产业化合成AlN粉体性能和效率。
This review represents the research progress on the synthesis of aluminium nitride powder via carbon thermal reduction(CRN)in terms of the related reaction mechanism,Al_(2)O_(3)–C interface improvement,high specific surface area precursor preparation and reaction atmosphere regulation.In this review,the mass loss of the reaction process and the mass transfer process of whisker growth were discussed based on the gas–solid reaction,and the phenomenon of the continuation of the morphology of the synthesized products and precursors as well as the mechanism of the formation of the transformed intermediate state compounds such as Al_(2)O_(3)from Al—O—C and Al—C—N were analyzed according to the solid-solid reaction control mechanism.Moreover,the solid-solid reaction mechanism indicates that C atoms act as electron exchange mediators to promote N_(2)decomposition,and the reaction proceeds in a positive direction due to their ability to both gain and lose electrons.Recent research work on the CRN method for the synthesis of AlN powder was summarized.Summary and prospects These researches involve 1)the introduction of organic dispersants to increase the dispersion of C and Al_(2)O_(3)particles,and the formation of a uniform binding interface between particles,2)the introduction of a binder(i.e.,an organic carbon source)on the uniform coating of Al_(2)O_(3)particles and pyrolysis to form a uniform combination of cracked carbon and Al_(2)O_(3)particles,3)the decomposition of organic matter,combustion synthesis and sol–gel and foam-injection coagulation to obtain precursors with a porous structure and a high specific surface area and the uniform mixing of aluminium and carbon sources in a micron scale,thus reducing the conditions for complete reaction and synthesizes high-quality nanopowders of AlN and 4)increasing the substitution(flow)efficiency of the reaction atmosphere,reducing the partial pressure of CO and increasing the partial pressure of N_(2)to promote the positive synthesis reaction.According to the
作者
袁振侠
李大海
徐佳豪
邵远
陆有军
王燕民
YUAN Zhenxia;LI Dahai;XU Jiahao;SAO Yuan;LU Youjun;WANG Yanmin(Ningxia North Ceramic New Material Technology Co.,Ltd,Yinchuan,750200,China;College of Materials Science and Engineering,North Minzu University,Yinchuan,750021,China;Carbon-based advanced ceramic preparation technology National and local joint engineering research center,Yinchuan,750021,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou,510640,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2024年第12期3884-3895,共12页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(U23A20562)
宁夏重点研发专项(2023BDE92008)
银川市科技创新领军人才培养工程(2023LJRC08)资助
银川市科技计划项目(2023GXZD17)。
关键词
氮化铝粉体
碳热还原氮化
前驱体
aluminium nitride powders
carbothermal reduction nitriding
precursors
