球磨介质对氮化硅粉体的微观形貌和表面氧化硅层的影响  

Effect of ball milling medium on morphology and surface silicon oxide layer of silicon nitride powder

作　　者：郗威 周杨杨 刘鹏飞 韩召 XI Wei;ZHOU Yangyang;LIU Pengfei;HAN Zhao(School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243000,China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243000

出　　处：《中国粉体技术》2023年第6期82-90,共9页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:52072381。

摘　　要：氮化硅(Si_(3)N_(4))粉体极易氧化,表面氧化硅层氧含量过高会对Si_(3)N_(4)陶瓷的力学性能和导热性能产生不利影响。在球磨法细化Si_(3)N_(4)粉体过程中,分别选取去离子水、无水乙醇和质量分数为20%的氢氧化钠(NaOH)溶液作为3种球磨介质,研究不同球磨介质对细化后的Si_(3)N_(4)纳米粉体的颗粒粒径和表面氧化硅层氧含量的影响;采用X射线衍射分析仪、激光粒径仪、场发射扫描电子显微镜、高分辨透射电子显微镜、氧氮分析仪、傅里叶变换红外光谱仪和X射线光电子能谱仪分析Si_(3)N_(4)纳米粉体的物相组成、粒径分布、微观形貌、表面氧化硅层的氧含量、化学基团和化学键种类及浓度;探讨碱液法球磨制备表面氧化硅层的氧含量较低的Si_(3)N_(4)粉体的机制。结果表明:以NaOH溶液为球磨介质时,Si_(3)N_(4)粉体先与水反应生成非晶氧化硅层,NaOH再和氧化硅层发生反应,球磨过程加速了Si_(3)N_(4)粉体表面氧化硅层的溶解和剥离,降低了表面氧化硅层的氧含量,减小了颗粒粒径,实现了Si_(3)N_(4)粉体的细化;表面氧化硅层的氧的质量分数从1.00%仅增加到1.25%,颗粒平均粒径从3.50μm减小为0.71μm,微观形貌由长条状变成分散性较好的球形颗粒;球磨后的Si_(3)N_(4)纳米粉体的O—Si—O键的物质的量浓度从15.06%减小为11.24%;与去离子水和无水乙醇相比,以NaOH溶液为最优球磨介质。Silicon nitride(Si_(3)N_(4))powder is prone to oxidation,and high oxygen content of surface silicon oxide layer have adverse effects on the mechanical and thermal conductivity of Si_(3)N_(4)ceramics.In the process of refining Si_(3)N_(4)powder by ball milling,deionized water,anhydrous ethanol and 20%sodium hydroxide(NaOH)solution were selected as ball milling media,respectively.X-ray diffraction analyzer,laser particle size analyzer,field emission scanning electron microscope,high resolution transmission electron microscope,oxygen nitrogen analyzer,Fourier transform infrared spectrometer and X-ray photoelectron spectrometer were used to analyze the phase composition,particle size distribution,morphology,oxygen content of surface silicon oxide layer,chemical group and chemical bond type and concentration of Si_(3)N_(4)nano powder.The mechanism of preparing Si_(3)N_(4)powder with low oxygen content of surface silicon oxide layer by alkaline ball milling was explored.The results show that when NaOH solution is used as the ball milling medium,Si_(3)N_(4)powder first reacts with water to form a surface silicon oxide layer,and then Na OH reacts with the surface silicon oxide layer.The ball milling process accelerates the dissolution and peeling of the amorphous silicon oxide layer on the surface of Si_(3)N_(4)powder,reduces oxygen content of surface silicon oxide layer and particle size,and achieves the refinement of Si_(3)N_(4)powder.The mass fraction of oxygen in Si_(3)N_(4)powder only increase from 1.00%to1.25%,but the particle size decrease from 3.50μm to 0.71μm.The morphology changed from long strip to good dispersive spherical particles.The O—Si—O bond content of ball milled Si_(3)N_(4)nano powder decreases from 15.06%to 11.24%.Compared with deionized water and anhydrous ethanol,Na OH solution is the optimal milling medium.

关 键 词：球磨介质 氮化硅粉体 颗粒微观形貌 表面氧化硅层 氧含量 

分 类 号：TQ170[化学工程—硅酸盐工业] TB44[一般工业技术]