稀土硅酸盐陶瓷材料研究进展

稀土硅酸盐陶瓷具有良好的抗水蒸气腐蚀性能和较低的热膨胀系数,被认为是下一代硅基陶瓷环障涂层候选材料。研究发现,部分稀土硅酸盐陶瓷具有较低的热导率,使得它们兼具隔热和抗腐蚀的性能,有望成为硅基陶瓷环/热障一体化涂层材料。本文评述了稀土硅酸盐陶瓷的种类、本征热学性能、力学性能以及抗低熔点氧化物熔盐和水蒸气腐蚀的研究进展,并对其未来发展方向进行了展望。     

稀土氧化物对钛酸铝陶瓷显微结构和力学性能的影响

研究了添加稀土氧化物Y2O3和Y2O3+Nd2O3对钛酸铝陶瓷的烧结温度、力学性能和显微结构的影响.结果表明,添加1%的稀土氧化物可以降低钛酸铝陶瓷的烧结温度,改善其显微结构,提高其力学性能,尤其是添加1%的复合稀土氧化物(Y2O3+Nd2O3)后,钛酸铝陶瓷的抗折强度和断裂韧性是未添加的试样的1.96倍和1.82倍.其性能提高的主要原因是由于稀土元素的细晶强化、净化界面、固溶强化、自增韧补强等作用.     

稀土氧化物在功能陶瓷中的应用分析

综述了稀土氧化物在压电陶瓷，导电陶瓷，AlN陶瓷，ZrO2氧敏陶瓷，微波介质陶瓷中的应用现状，详细讨论了稀土的作用机理，再现了稀土氧化物掺杂改性的规律，为利用稀土氧化物掺改性功能陶瓷提供一定的参考和指导作用，并且为稀土氧化物的应用指明了方向，简述了该领域应用研究的发展方向。     

稀土对激光熔覆生物陶瓷涂层性能的影响

采用激光熔覆的工艺方法制备出含稀土的硼CaP陶瓷涂层,通过X射线衍射仪(XRD)、扫描电镜(SEM)和体外模拟体液(SBF)浸泡实验,对涂层物相组成、组织形貌和生物活性进行了研究。结果表明添加稀土氧化物La2O3之后,羟基磷灰石衍射峰明显上升,晶粒明显细化,涂层表面沉积的类骨磷灰石明显增多,生物活性明显改善。     

稀土氧化物在陶瓷中的应用

针对我国稀土资源得天独厚的现状，从稀土元素的原子结构和化学特性出发，简略介绍了稀土的应用领域，较详细地阐述了稀土在陶瓷色釉料、功能陶瓷、各种氧化物陶瓷和非氧化物陶瓷中的应用。     

国内工业陶瓷文献题录及文摘(十二)

200169 碳化硅材料的氧化及抗氧化研究·陶瓷科学与艺术,2002,36(1):7～13 本文在简要介绍SiC材料的氧化机理之上,就人们在改善SiC材料的抗氧化性能方面的工作做了一个小结。200170 稀土氧化物在功能陶瓷中的应用分析·陶瓷科学与艺术,2002,36 (1):14～16 综述了稀土氧化物在压电陶瓷、导电陶瓷、AIN陶瓷、ZrO_2氧敏陶瓷、微波介质陶瓷中的应用现状,详细讨论了稀土的作用机理,再现了稀土氧化物掺杂改性的规律,为利用稀土氧化物掺杂改性功能陶瓷     

稀土氧化物在陶瓷工业中的应用

本文论述了稀土氧化物在陶瓷坯釉料，陶瓷颜料，陶瓷金水，工业陶瓷等方面的应用研究，初步探讨了稀土氧化物的作用机理，表明了稀土氧化物在陶瓷工业中有着广泛的作用并有着广阔的应用前景。     

复合稀土氧化物对氧化铝陶瓷耐磨性能的影响研究

讨论了不同类型和不同量的六种稀土氧化物La2O3、ceO2、Y2O3、Sm2O3、Nd2O3、Dy2O3对氧化铝陶瓷进行掺杂的试验过程,研究表明：某两种或两种以上稀土氧化物一起添加到氧化铝陶瓷中,比单一稀土氧化物添加到氧化铝陶瓷中对提高陶瓷耐磨损性能的效果要好。     

电热爆炸超高速喷涂原位合成碳化钼陶瓷涂层的实验研究

利用电热爆炸超高速喷涂技术在45#钢基体上原位合成碳化钼陶瓷涂层试样,利用X衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)和显微硬度计对涂层的成分、显微组织和显微硬度进行了分析.结果显示涂层组织致密,空隙率低,没有分层现象,涂层和基体之间形成了冶金结合.XRD显示涂层中主要是原位合成的Mo2C、MoC和.Mo相,没有氧化物的生成.涂层中形成的碳化钼陶瓷相,具有弥散强化的作用,提高了涂层的硬度.     

稀土氧化物对Na_(0.5)Bi_(0.5)TiO_3基无铅压电陶瓷结构和性能的影响

综述了稀土氧化物在Na0.5Bi0.5TiO3(BNT)基无铅压电陶瓷中的应用现状和发展前景,并阐述了稀土氧化物在BNT基无铅压电陶瓷中的作用机理。     

Current research art of rare earth compound modified SiC-CMCs for enhanced wet-oxygen corrosion resistance

Silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiC-CMCs) currently present wide application potential as thermal structure component in aero-engine. To solve the wet-oxygen corrosion induced degradation of SiC-CMCs attract growing global attention. In this work, the main preparation methods via introduction of rare earth compound like rare earth phosphates, rare earth oxides, rare earth silicates and rare earth silicide carbides into SiC-CMCs matrix and interphase and their microstructures, mechanical properties and wet-oxygen corrosion resistance are summarized in details. Finally, the challenges and prospects of rare earth compound modified SiC-CMCs are proposed.     

添加稀土氧化物对合成MgO－CaO系熟料的烧结和抗水化性能的影响

研究了稀土氧化物对二步合成ＭｇＯ－ＣａＯ砂的体积密度、抗水化性和抗渣性能的影响。结果表明：加入少量稀土氧化物可明显地促进合成ＭｇＯ－ＣａＯ砂的烧结和增强其抗水化性，且对合成砂的抗渣性能无明显不良影响。     

Structural characteristics and high-temperature oxidation behaviour of nano-HfO2-doped thermal barrier coatings

The uneven growth of thermally grown oxides (TGOs) in thermal barrier coating systems is an important cause of cracking failure at the coating interface in high-temperature environments. The doping of rare earth elements in the bonding layer can effectively inhibit the formation of spinel oxides in the TGO and improve the high-temperature oxidation resistance of the coating. However, a single rare earth element has a limited effect on inhibiting TGO failure. In this study, a NiCoCrAlYHf coating was prepared using a supersonic flame spraying (HVOF) technique. The effects of HfO₂ doping on the high-temperature oxidation behaviour of the coatings and diffusion behaviour of metallic elements in the coatings were investigated at 1100 °C. The results showed that the nano-sized HfO₂ filled the pores between the powder particles and improved the hardness of the coating. During the high-temperature oxidation process, the oxides formed by Hf and Y had a large size and low solubility, which effectively blocked the diffusion of Al. This slowed the generation of spinel oxides, effectively inhibited the growth of the TGO, it inhibits the initiation and propagation of cracks within the coating, reduces damage to the coating from tensile and compressive stresses at the interface, and improved the high-temperature oxidation resistance of the coating.     

表面改性技术在连铸结晶器上的应用进展

表面处理是提高结晶器耐磨性和高温耐腐蚀性的有效手段,通过对镀层的改进可以达到提高连铸坯质量、延长结晶器寿命、提高铸坯的表面质量和降低生产成本的目的。综述了国内外最新的涂、镀层在结晶器上的应用情况及其特点。主要有热喷涂Ni-Cr镀层、超厚Ni-Fe镀层、Ni-Co合金、Ni-Fe-W-Co镀层、Ni-P复合镀层、陶瓷涂层、Hipercoat和Hiper H3镀层、纳米复合镀层等。同时指出采用稀土和纳米复合镀层等一些新型复合镀层是今后结晶器镀层的发展方向。     

Microstructure and thermal shock resistance of Nd2O3-doped YSZ-based thermal barrier coatings

To study the impact of rare earth oxide doping on the thermal failure of thermal barrier coatings, 0.5 mol%, 1.0 mol% and 1.5 mol% Nd₂O₃-doped YSZ coatings were prepared by explosive spraying. SEM, XRD, EDS and microhardness testing were used to analyse the effect of different rare earth oxide doping contents on the morphology, composition and mechanical properties of the coatings. With an increase in the Nd₂O₃ doping content, the porosity of the coatings was reduced. The decrease in the porosity increased the compactness of the coatings and improved the microhardness and fracture toughness. The bonding strength and thermal shock resistance of the coatings were the highest among the samples herein when the rare earth doping content was 1.0 mol%, and the values were 37.6 MPa and 200 times, respectively. The thermal shock failure mode of the coating was mainly due to the exfoliation of the inner layer of the ceramic layer. The luminous intensity of the coating increased with increasing rare earth oxide doping content, and the emission spectrum of the Nd₂O₃-modified YSZ coating after the thermal shock test produced a new emission peak at 594 nm, which decreased at 708 nm.     

Microstructure and luminescence properties of YSZ-based thermal barrier coatings modified by Eu2O3

In order to study the variation of rare earth oxides during thermal failure of thermal barrier coatings, Eu2O3-doped YSZ coatings with 0.5 mol%, 1.0 mol% and 1.5 mol% were prepared by explosive spraying. SEM, XRD, EDS and microhardness tester were used to analyze the effect of different rare earth oxide doping content on the morphology, composition and mechanical properties of the coatings. The results showed that with the increase of rare earth oxide doping content, the porosity of the coatings decreased, and the microhardness and fracture toughness increased. When the doping amount of rare earth oxide is 1.0 mol%, the bonding strength and thermal cycle times of the coating are the highest, 33.4 Mpa and 185 times respectively. With the increase of the doping amount of rare earth, the luminous intensity of the sprayed coating increases. After thermal shock test, the luminous intensity of Eu2O3-doped YSZ coatings at 592 and 608 nm decreased to a certain extent.     

锌及镀锌层稀土转化膜研究进展

锌及镀锌层表面稀土转化膜具有良好的耐蚀性能和无毒、无污染等优点,是最有希望替代铬酸盐处理的转化膜之一,具有良好的发展前景.本文综述了国内外关于锌及镀锌层上单一稀土转化膜的成膜工艺及其机理,并概述了国内外稀土复合膜的研究成果.     

钛酸钡基电子陶瓷材料的改性进展

钛酸钡基电子陶瓷材料广泛应用于电容器、集成电路、传感器及热敏电阻等领域。高容量、小型化、抗击穿及低损耗等工业需求对钛酸钡基电子陶瓷材料的性能提出更高的要求,改性则是提高陶瓷材料性能的主要手段。综述了近年来钛酸钡基电子陶瓷材料在掺杂改性、复合改性及物理改性方面的研究进展。分析了钛酸钡基电子陶瓷材料在改性中存在的问题,比如：常规元素掺杂制备参数优化不足、稀土元素掺杂种类偏少、包覆效果待提升、聚合物陶瓷复合体综合性能欠佳、烧结工艺尚待优化等。提出了解决方法,比如：探索多种元素掺杂、优化工艺参数、改进包覆与聚合方式等。指出了钛酸钡基电子陶瓷材料的未来发展方向,即：强化烧结过程中晶粒尺寸、晶体形状、组分调控的机理研究,选取更多稀土元素进行改性,探索包覆掺杂改性、聚合物复合改性等新工艺。