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Study on Hydro-thermal Processing of Cubic Boron Nitride by Laser Beam Irradiation

激光束辐照水热处理立方氮化硼的研究

基本信息

批准号：
11555039
负责人：
TOKURA Hitoshi
金额：
$ 8.77万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

When solid materials are irradiated by laser beam in the presence of water, they are heated to high temperature, further chemical reaction between solid materials and radicals which are produced from water is expected. The aim of this research is to process cubic boron nitride or other ceramic materials by using these reactions.Firstly water and water which dissolving gases, such as methane, hydrogen and oxygen, were irradiated by an ArF excimer laser beam, an Ar ion laser beam and a YAG laser beam and the luminescences were examined by Spectrophotometry. As the results ArF excimer laser beam can excite water and radicals such as O2+, OH, H2, O2 and etc. are produced. While the other laser beams could not excite one but heat the solid materials. Secondly approximately 60 volume percent of a chamber was filled with water and the upper part was filled with methane. The pressure of the methane dissolved in water was 350kPa. The gas pressure of the upper part of the chamber was 100kPa. The … More n ArF excimer laser beam was focused just below the water surface. Consequently, film was deposited on the water around the beam-focus area. From a TEM image, small particles of about 30nm in diameter are connected with each other in the mesh.Thirdly Si3N4 ceramics were immersed in water and ArF excimer laser beam was irradiated. Although the amics were placed 1mm away from the laser beam, the color of ceramics adjacent to the laser beam changed. ArF excimer laser beam can excite water as mentioned above, on the other hand, Ar ion laser beam can not excite water but rather heats the ceramic material. The same Si3N4 ceramics were irradiated by an Ar ion laser in both water and air. On both cases holes are formed, however the formed features are different each other and one processed in water seems to be partly etched. This depends on the hydro-thermal reaction between water and heated ceramics. It is also expected to process cBN which react with water at high temperature. cBN single crystal was irradiated in water and water vapor environments. In both cases very clear shaped holes were formed. In particular one in water vapor showed high crystallinity on electron diffraction. Also crystal habits were observed around the holes. Less

当固体材料在有水存在的情况下用激光照射时，固体材料被加热到高温，预计固体材料与水产生的自由基之间会发生进一步的化学反应。本研究的目的是利用这些反应来加工立方氮化硼或其他陶瓷材料。首先用ArF准分子激光束、Ar离子激光束和YAG激光束照射水和溶解甲烷、氢、氧等气体的水，用分光光度法测定其发光特性。结果表明，ArF准分子激光束能激发水，产生O2+、OH、H2、O2等自由基。而其他激光束只能加热固体材料而不能激发。其次，大约60%的空间充满了水，上部充满了甲烷。溶解在水中的甲烷压力为350kPa。箱体上部气体压力为100kPa。更多的ArF准分子激光束聚焦在水面以下。因此，在光束聚焦区域周围的水面上沉积了薄膜。从TEM图像来看，直径约30nm的小颗粒在网格中相互连接。再次将Si3N4陶瓷浸入水中，辐照ArF准分子激光束。虽然放置在距离激光束1mm的地方，但靠近激光束的陶瓷的颜色发生了变化。ArF准分子激光束可以如上所述激发水，另一方面，Ar离子激光束不能激发水，而是加热陶瓷材料。同样的Si3N4陶瓷用氩离子激光在水和空气中照射。在这两种情况下都形成了孔，但是形成的特征彼此不同，并且在水中处理的孔似乎部分被蚀刻。这取决于水和受热陶瓷之间的水热反应。它还有望处理与水在高温下反应的cBN。cBN单晶在水和水蒸气环境下辐照。在这两种情况下，都形成了形状非常清晰的孔。特别是水蒸气中的一种，在电子衍射上显示出较高的结晶度。在孔周围也观察到晶体习性。少