高温高压下透明纳米聚晶金刚石的合成与微观形貌  

Synthesis and Microstructure of Transparent Nano-crystalline Diamond Under High Temperature and High Pressure

作　　者：张松朋 但雅倩 陈旺 江皓 崔思雯 赵行斌 朱品文[2] 崔田 马帅领 ZHANG Songpeng;DAN Yaqian;CHEN Wang;JIANG Hao;CUI Siwen;ZHAO Xingbin;ZHU Pinwen;CUI Tian;MA Shuailing(School of Physical Science and Technology&Institute of High Pressure Physics,Ningbo University,Ningbo 315211,China;State Key Laboratory of Superhard Materials,Jilin University,Changchun 130012,China)

机构地区：[1]宁波大学物理科学与技术学院&高压物理科学研究院,浙江宁波315211 [2]吉林大学,超硬材料国家重点实验室,长春130012

出　　处：《硅酸盐学报》2024年第3期804-811,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(12204254,11904119,11974131,12204254,12174348);浙江省自然科学基金项目(2018YFA 0703400,LQ23A040005);超硬材料国家重点实验室开放课题202311,202107和2021R01004的资助。

摘　　要：透明陶瓷是一种具有广泛应用前景的新一代无机非金属材料,而透明纳米聚晶金刚石具有极高的硬度和良好的透光性,是透明陶瓷中极具代表的典型材料之一。本工作介绍了一种在高温高压条件下制备的超硬透明陶瓷—纳米聚晶金刚石,并对其性能进行了X射线衍射、扫描电子显微镜、透射电子显微镜、Raman等测试分析。结果表明:高温高压法是一种制备高性能透明陶瓷的有效途径,石墨原材料可在15 GPa、2 600℃、保温1 min条件下转变为透明的纳米聚晶金刚石。同时,样品腔的温度梯度导致样品透明度不均匀,温度的升高有利于增加纳米聚晶金刚石的透明度。形貌测试分析结果表明样品存在马氏体相变的层状结构和扩散型相变的均匀颗粒结构,层厚和晶粒尺寸均约为100 nm。高压和应力导致样品内部出现部分位错,有助于提高样品的力学强度。纳米聚晶金刚石作为硬度最高的透明陶瓷,有望在极端条件下的特殊光学窗口等领域得到广泛应用。Introduction Transparent ceramics are polycrystalline inorganic nonmetallic materials that are transparent in the visible range and have some superior characteristics(i.e.,high melting point,high strength,high insulation,corrosion resistance,high temperature resistance,and good light transmission).Diamond as a hardest substance in nature has an extremely high thermal conductivity,a wide spectral transmission range and a good chemical stability as an ideal transparent ceramic material in harsh and extreme environments.However,the single crystal of diamond is brittle and easily broken along the cleavage plane(111),greatly restricting the application of single crystal diamond.Nanocrystalline diamond(NPD)is a polymer of small diamond particles in nano-scale,and the grains are directly bonded by diamond to form a compact structure.The macroscopic properties of nanocrystalline diamond show an isotropy,and there is no directional and disfoliating plane due to the disordered accumulation between particles,having the better mechanical properties,compared to single crystal diamond.The nano-polycrystalline diamond can be prepared,but the preparation of transparent nano-polycrystalline diamond and its application in the field of light transmission are rarely reported.Little work on the transparent mechanism and defect formation mechanism of nano-polycrystalline diamond have been done yet.In this paper,a nanocrystalline diamond was prepared by a high-temperature and high-pressure method.In addition,the mechanical properties were also investigated.Methods A high purity graphite powder(99.9999%in mass fraction)as a precursor was prepressed into a cylindrical shape(φ=2.5 mm,h=2 mm),wrapped with aluminum oxide,and assembled.The pressure was uniformly increased to 15 GPa for 8 h.Afterwards,a rhenium(Re)heater was used for heating,and the temperature was uniformly increased to 1800,2300℃,and 2600℃at 200℃/min.After holding for while,the temperature was slowly reduced to room temperature at 200℃/min,and the pressure was slow

关 键 词：透明陶瓷 透明纳米聚晶金刚石 高温高压合成 

分 类 号：TQ175[化学工程—硅酸盐工业]