铌、钽酸盐系列陶瓷材料的结构特性及其研究进展

铌、钽酸盐系列陶瓷材料的研究近年来受到广泛的关注，笔者介绍了铌、钽酸盐的晶体结构类型、特性以及国内外的研究进展。     

Sialon陶瓷材料的结构、性质及应用

系统地评述了不同种类单相Sialon陶瓷的结构特征和物理、化学性质,并介绍了Sialon在冶金工业等方面的应用.单相Sialon陶瓷中,β'-Sialon强度和韧性最高,α'-Sialon硬度和耐磨性最好,O'-Sialon抗氧化性最佳.     

碳化硅质结构陶瓷材料的制造、性能和使用范围

阐述由碳化硅制造陶瓷材料的主要方法及其工艺特点，还介绍了该材料的性能和使用范围。     

令人瞩目的氮化铝陶瓷材料

氮化铝是非氧化性高功能陶瓷材料，具有许多优异的物理化学性质，日益被人们所重视。本文对ＡＩＮ的应用和制备作了评述，介绍了为提高纯度在合成ＡＩＮ路线方面的研究进展，综述了制备ＡＩＮ的最新研究成果。     

热分析在新型陶瓷材料中的应用

本文采用法国Ｓｅｔａｒａｍ ＴＧ－ＤＴＡ９２热分析仪对几种磁性陶瓷材料－锰锌铁氧体和镍锌铁氧体进行了实验研究，并由热分析结果分析了它们的反应特性，该工作对磁性陶瓷的加工具有指导意义。     

高辐射红外陶瓷材料的研究进展及应用

陶瓷材料有着优良的红外辐射性能,是一种绿色环保型材料,有着广阔的应用前景,越来越受到人们的广泛关注。综述了国内外高辐射红外陶瓷材料的研究概况,同时较深入的探讨了红外辐射产生机理,分别介绍了高辐射陶瓷材料在加热节能、医疗保健、航天航空、建筑、抗菌、红外导电导热等方面的应用情况,最后对高辐射红外陶瓷材料未来研究发展的趋势作出展望。     

电力工业中应用的陶瓷材料

对电力生产与电参输配过程中已经应用与将要应用的陶瓷材料简要介绍。     

Synthesis and photoluminescence characteristics of blue‐green luminescent aluminum oxynitride

Aluminum oxynitride (AlON), which can be regarded a nitrogen‐stabilized cubic γ‐Al₂O₃, has attracted attention in terms of its good mechanical, chemical, and optical stability. Because of its optical inertness, however, photoluminescence (PL) emission from nominally pure AlON has not been carefully investigated and evaluated. In this work, we prepared visibly luminescent AlON by nitridation of γ‐Al₂O₃ under N₂ atmosphere without adding aluminum nitride (AlN) using a high‐frequency induction heating unit. The resulting AlON exhibits a broad PL emission in the blue/green spectral region under excitation with light of ~260 nm. In the luminescent AlON sample, the excitation and emission events will occur at different sites; the electron transfer from the excitation site to the emission site is preceded by the radiative recombination process. It has also been found that the PL peak wavelength shows an anomalous blue shift by ~50 nm with increasing temperature from 78 to 500 K. The observed temperature dependent PL characteristics are governed by thermalization among multiple emitting levels. Aluminum vacancies and oxygen vacancies, both of which are introduced into the crystalline lattice during nitridation without the presence of AlN, are very likely candidates for the excitation and emission centers, respectively. Hence, the present direct nitridation method provides a simple and effective way to add an additional optical functionality to otherwise optically inactive AlON.     

AlON的氧化行为及其与MgO和MgAl2O4的作用

利用TG DTA和XRD研究了氧氮化铝(AlON )在高温下的氧化行为及其与MgO和MgAl2 O4 的作用。结果表明 :AlON在 85 0℃左右开始氧化 ,1170℃左右氧化最为剧烈 ;MgO和MgAl2 O4 在 12 0 0℃都能与AlON形成固溶体 ,且后者更易形成 ;形成固溶体对AlON的氧化有一定的抑制作用。     

Hydrothermal synthesis and characterization of In2O3-ZnGa2O4 nanocomposites and their application in IGZO ceramics

Poly-crystalline In₂O₃-ZnGa₂O₄ nanocomposites were successfully synthesized by hydrothermal method with a mixed solution of In, Ga and Zn nitrates with equal mole ratio (In: Ga: Zn=1:1:1) and the ammonia was used as the precipitant. The effects of hydrothermal temperature and pH value of the mixed solution on the properties of the nanocomposites were investigated. The microstructure of the prepared In₂O₃-ZnGa₂O₄ nanocomposites was characterized by SEM and TEM, respectively. The growth mechanisms of In₂O₃-ZnGa₂O₄ nanocomposites were also preliminarily discussed in this study. Results reveal that the IGZO ceramics prepared by In₂O₃-ZnGa₂O₄ nanocomposites own a high relative density of 99.5% and low resistivity of 1.2?mΩ·cm, which can be applied to the preparation of IGZO thin film with superior performance.     

氧氮化铝陶瓷的合成与应用

介绍了氧氨化铝的基本性能、合成研究的最新进展、烧结及其抗氧化性、热稳定性和应用。     

High-entropy silicide ceramics developed from (TiZrNbMoW)Si2 formulation doped with aluminum

We report a success in synthesizing high entropy silicides (HES) compounds and manufacturing well-densified HES ceramics through spark plasma sintering. For a designed chemical formula as (Ti_0.2Zr_0.2Nb_0.2Mo_0.2W_0.2)Si₂, the as-synthesized HES showed a formula as (Ti_0.22Zr_0.06Nb_0.29Mo_0.22W_0.21)Si₂ with zirconium partially oxidized into zirconia. Doping with aluminum resulted in a HES with the same composition, promoted formation of ZrSi₂ and Al₂O₃. XRD analysis of as-synthesized HES is well supported by the calculated diffraction data based on a 2 × 3 × 1 supercell with HCP crystal structure and experimental chemical composition. The cations in this HES crystal structure can occupy their positions randomly with little change of its lattice parameters and formation enthalpy.     

氧氮化硅结合碳化硅制品的生产与使用

以工业用黑色碳化硅砂、硅粉为主要原料，研制出了导热性能优良、抗热震性好、耐高温、耐侵蚀及耐磨损，且生产工艺较简单、成本较低的氧氮化硅结合的碳化硅制品．该产品已广泛应用于冶金炉、化工设备及发电用锅炉的内衬，并取得了较满意的效果。     

Effect of ZnO doping on structural,dielectric, ferroelectric and piezoelectric properties of BaZr0.1Ti0.9O3 ceramics

This study provides a fundamental understanding of structural, dielectric, ferroelectric and piezoelectric properties of bare and ZnO-doped BaZr_0.1Ti_0.9O₃ (BZT) solid solutions synthesized using mechanochemical activation technique. Structural investigation has been carried out using XRD patterns of the synthesized compositions by Rietveld refinement method. It confirms the formation of tetragonal phase with P4mm space group for ZnO doping up to 2.5 wt%, while in 5.0 wt% ZnO-doped sample, BZT and ZnO are distributed as individual phases of tetragonal (P4mm) and hexagonal (P6₃mc), respectively. Microstructural analysis shows that average grain size increases quite rapidly with the increase of ZnO content. Detailed analysis of dielectric constant as a function of temperature for the prepared samples shows that the frequency independent dielectric constant maximum shifts to lower temperature with increase in ZnO doping. The ferroelectric ordering is confirmed using P-E loop measurements. The piezoelectric constant of the synthesized specimens were found to decrease with increasing ZnO content.     

Hydrolysis control of alumina and AlN mixture for aqueous colloidal processing of aluminum oxynitride

AlN powder, surface modified by phosphoric acid treatment was employed for the aqueous colloidal processing of Aluminum Oxynitride (AlON). The hydrolysis of AlN leads to the formation of Al(OH)₃ and NH₃. On mixing of alumina to the phosphoric acid treated AlN in aqueous medium this reaction reoccurred. The phosphoric acid shield around AlN particles is ruptured by alumina addition thus exposing AlN surface to hydrolysis reactions. Hence hydrolysis can be effectively controlled by providing a phosphoric acid treatment to the alumina, prior to its addition to AlN. AlON precursor mixture thus obtained can be successfully shaped by an aqueous slip casting process and sintered to phase pure AlON at 1925 °C for 2 h. Viscosity, pH, SEM, FTIR, and XRD measurements are employed to elucidate the effect of Al₂O₃ addition on surface modified AlN for colloidal processing of AlON.     

Formation of the nanocrystalline mesoporous niobium-silicon oxynitride

A new method for the preparation of crystalline mesoporous niobium-silicon oxynitride (NbSiON) by the straightforward technique is described. The characterization has been performed by various techniques showing that the material has: (i) the specific surface area of 160 m² g⁻¹ and mesopores centered at 4.0 nm from N₂ adsorption, (ii) the crystalline walls from wide-angle XRD pattern, (iii) the wormhole-like framework from low-angle XRD pattern and TEM images, (iv) the nanobelts and nanowires morphology from TEM images, and (v) Si–O–Nb and Si–N–Nb bonds from FTIR spectroscopy.     

Fabrication and properties of borazine derived boron nitride bonded porous silicon aluminum oxynitride wave-transparent composite

Boron nitride bonded porous silicon aluminum oxynitride composite was fabricated by gel-casting, precursor infiltration and pyrolysis process, and the composition, microstructure, mechanical and dialectical properties of the composite were characterized. The results show that the composite is comprised of β-SiAlON (z = 3) synthesized from mixed ceramic powders, and continuous h-BN pyrolyzed from borazine, with a relatively high porosity of 24.21%. The flexural strength, elastic modulus and fracture toughness of the composite are 178.58 MPa, 75.51 GPa and 4.54 MPa m^1/2, respectively. The sintering shrinkage of SiAlON ceramics can be greatly decreased by the borazine infiltration and pyrolysis process. The existence of h-BN phase and the high porosity reduce the values of dielectric constant and loss tangent of the composite, which are 3.51–3.69 and 0.9–3.1 × 10⁻³ at the frequency from 7 to 18 GHz with the elevating temperature from 25 to 1200 °C.