Development of High Thermal Conductivity Silicon Nitride Ceramics Using Rare-Earth Metal Complexes as the Precursors for Sintering Aids

以稀土金属配合物为烧结助剂前驱体开发高导热氮化硅陶瓷

基本信息

批准号：
16550159
负责人：
KITAYAMA Mikito
金额：
$ 2.43万
依托单位：
Fukuoka Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

1. Synthesis of rare-earth metal complexes, and search for appropriate solventsSelecting CN-as a ligand without oxygen atom, the synthesis of cyano complex was examined from an aqueous solution of Y3+, which produced only hydroxides in any conditions. Selecting ethylene diamine (ED), the [Y(ED)3]C13 complex was successfully synthesized using ED itself as a solvent, which was confirmed to be highly hygroscopic.It was found that a non-aqueous solvent CH3CN dissolved YC13. Using it as a solvent, a [Y(ED)3]C13 solution was synthesized using a stoichiometric amount of ED. Powders of Silicon nitride and sintering aids were mixed with the solution and were subsequently dried, which was a new method for homogeneously adding the complex.2. Fabrication of silicon nitride sintered bodies and their evaluationAdding [Y(ED)3]C13 as a "de-oxygen sintering aid", silicon nitride sintered bodies were fabricated. However, they showed very low sintered densities about 60 %. Estimated thermal conductivities of dense sintered bodies using the Maxwell relationship were found to be higher than those without "de-oxygen sintering aid". The XRD showed the existence of Y2Si3N6 which had never reported. The dense sintered body fabricated by hot-pressing at 1800℃ was annealed at 1850℃ to finish the phase transformation. This resulted in significant swelling of sintered body, which would be due to the densification before the complete decomposition of complex.3. Effect of the nitrides and carbides of the group IV elementsSilicon nitride sintered bodies fabricated by adding the nitrides and carbides of the group IV elements were evaluated. Although the thermodynamic calculations predicted that only the ZrN and HfN could act as the "de-oxygen sintering aid" among MX (M=Ti, Zr or Hf, X=N or C), all the sintered bodies showed lower thermal conductivities than those without MX. It was found that the group IV element nitrides significantly improved densification.

1.稀土金属配合物的合成，并寻找合适的溶剂选择CN-作为不含氧原子的配体，以Y3+水溶液为原料考察氰基配合物的合成，在任何条件下均只产生氢氧化物。 ED），使用ED本身作为溶剂成功合成了[Y(ED)3]C13配合物，并证实其具有高吸湿性。使用非水溶剂CH3CN溶解YCl3，使用化学计量的ED合成[Y(ED)3]Cl3溶液，将氮化硅粉末和烧结助剂与该溶液混合，然后干燥， 2．氮化硅烧结体的制备及其评价添加[Y(ED)3]C13作为配合物。然而，使用“脱氧烧结助剂”制造的氮化硅烧结体的烧结密度非常低，约为60%。发现使用麦克斯韦关系式估计的致密烧结体的导热率高于没有“脱氧”的烧结体。 XRD显示存在从未报道过的Y2Si3N6的存在。通过100℃热压制备致密烧结体1800℃退火，1850℃完成相变，导致烧结体明显膨胀，这可能是由于配合物完全分解之前的致密化所致。 3．尽管热力学计算预测只有ZrN和ZrN，但对通过添加IV族元素的氮化物和碳化物制造的烧结体进行了评估。 HfN可以作为MX（M=Ti、Zr或Hf，X=N或C）中的“脱氧烧结助剂”，所有烧结体均表现出比不含MX的烧结体更低的热导率。氮化物元素显着提高了致密化。