DEVELOPMENT OF HIGH PERFORMANCE SILICON NITRIDE CERAMICS COATED WITH MULLITE

高性能莫来石涂层氮化硅陶瓷的研制

基本信息

批准号：
05555237
负责人：
HATTORI Makoto
金额：
$ 4.67万
依托单位：
YONAGO NATIONAL COLLEGE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05555237/
关键词：
CERAMICS GRADIENT INTERFACE SURFACE MODIFICATION AUTOCLAVE NON-OXIDE CORROSION RESISTANCE STRUCTURAL MATERIAL COMPOSITE

项目摘要

It is well known that Si_3N_4 ceramics are readily susceptible to high-temperature oxidation and hydrothermal corrosion. Mullite and Si_3N_4 have very close coefficients of thermal expansion, suggesting a durable coating/substrate system can be made. In general, mullite shows better corrosion resistance to high-temperature oxidation and hydrothermal corrosion. The purpose of this project is to fabricate mullite coated Si_3N_4 ceramics and to characterize the oxide/nitride gradient nano-interface of the materials. Mullite coatings by using the hydrolysis of mixed alkoxides were applied to Si_3N_4 coupons and hydrothermally corroded Si_3N_4 coupons. The following resuls were obtained.1.X-ray diffraction indicated mullite powders to be a single phase, which were prepared by the hydrolysis of mixed alkoxides route and heated at above 900ﾟC.2.Mullite coatings on Si_3N_4 substrates can be successfully made by dipping in the mixed alkoxides solution. Coatings were approximately 30 to 80 mum thick on Si_3N_4 substrates after heating at 1300ﾟC.These materials have a oxide/nitride gradient interface at coating/substrate system.3.Coatings showed good adherence to the Si_3N_4 substrates, but poor density. Because of these features, the fracture strength and vickers hardness were relatively low compared to Si_3N_4 ceramics.

众所周知，SI_3N_4电化学物质很容易受到高温氧化和热液腐蚀的影响。 Mullite和SI_3N_4具有非常接近的热膨胀系数，这表明可以制造耐用的涂料/底物系统。通常，mullite表现出对高温氧化和热液腐蚀的更好耐腐蚀性。该项目的目的是制造Mullite涂层的SI_3N_4电化学物质，并表征材料的氧化物/氮化物梯度纳米接口。使用混合烷氧化物的水解涂层涂层用于SI_3N_4优惠券和水热腐蚀的SI_3N_4优惠券。 1.x射线衍射表明Mullite粉末是单相，通过混合烷氧化物途径的水解制备，并在900 c.2.c.2中加热SI_3N_4底物上的毛利石涂层可以通过在混合烷氧化物中浸入SI_3N_4底物上的毛状涂层。在1300 ﾟ处加热后，在Si_3n_4底物上涂层约为30至80 M厚。C。这些材料在涂层/底物系统处具有氧化物/氮化物梯度界面。3。涂料表现出对SI_3N_4底物的良好依从性，但密度较差。由于这些特征，与SI_3N_4陶瓷相比，断裂强度和Vickers硬度相对较低。