氧化钇微粉的制取

对草酸盐沉淀反应一般规律进行了动力学分析；通过降低晶体长大速度、增大溶液过饱和度等方法，研究了降低Y2O3粒径尺寸的途径。此法适合于工业大批量生产99.999%的高纯度Y2O3，且不引入杂质。     

χ射线荧光光谱法测定锆钇粉体中的氧化钇

采用粉末压片法,用χ射线荧光光谱法对锆钇粉体中氧化钇进行了测定,运用DJ数学模式进行干扰因素和基体效应的校正,其分析结果的精密度和准确度可满足生产分析要求。     

氧化钇微粉的制取

对草酸盐沉淀反应一般规律进行了动力学分析; 通过降低晶体长大速度、增大溶液过饱和度等方法, 研究了降低Y₂O₃粒径尺寸的途径。此法适合于工业大批量生产99.999%的高纯度Y₂O₃, 且不引入杂质。      

纳米氧化钇制备工艺研究

以纯氧化钇为原料,选用碳酸氢铵、草酸、草酸铵作为沉淀剂,控制进料和反应工艺,经沉淀过滤干燥后转移至820℃马弗炉中灼烧4 h,得到氧化钇粉体,并对其粒径、比表面积及扫描电镜等进行测试。结果表明：采用碳酸氢铵制备得到的氧化钇粉体的D₅₀粒径为1.256μm,比表面积为36.252 8 m²/g,氯的质量分数为68 mg/kg;具有较小的粒度及较大的比表面积,且粉末颗粒均匀,粉体符合预期纳米级别材料的要求。本方法的提出为纳米氧化钇的制备工艺提供了一条低成本、操作简便、高效率、无污染的途径。     

氧化钇纳米粉末的制备

使用草酸作沉淀剂，采用液相沉淀法成功制备了氧化钇纳米级粉末。对该粉末的扫描电镜图以及差热分析图等进行了分析以及对溶液的pH值、浓度、反应方式、分散剂及煅烧温度等因素进行了考察，得出了较为理想的工艺条件。在此工艺条件下制得的氧化钇粉末粒径为20～50m。     

新型氧化钇粉末及高纯致密氧化钇涂层的大气等离子喷涂制备

目前采用粉末原料通过等离子喷涂制备的最先进高纯氧化钇涂层的孔隙率通常为3%~5%。这种孔隙率的涂层在严重的腐蚀和侵蚀条件下会释放非常细小的颗粒。高纯氧化钇涂层主要应用于半导体领域,如,干法刻蚀腔室的抗冲蚀保护涂层(含氟和氯的等离子体),并且这些应用的需求条件也越来越严苛。当暴露于这种腐蚀性和侵蚀性气氛中时,涂层的致密度越高,它的耐侵蚀性就越强。侵蚀速率和细颗粒释放的降低将减少维护频率,从而提高生产效率。最近有文献报道通过悬浮液等离子喷涂(SPS)技术制备致密度更高的涂层,但这种新兴的工艺对制备技术提出了更高的挑战,如需要应对非常高的热通量和处理悬浮液作为原料来使用,增加了偏差的风险。本文开发了一种新的高纯氧化钇粉末,采用传统的大气等离子喷涂(APS)这种粉末能制备致密度范围与SPS技术相同的涂层。通过对粉末中颗粒致密度分布的调整和其狭窄精细粒度分布的微调得到一种独特的粉末材料来制备高质量的涂层。相比于通常报道的团聚和烧结粉末,采用Saint-Gobain ProPlasma HP等离子喷枪喷涂这种粉末显著降低了涂层的孔隙率,提高了沉积效率。     

碳酸氢铵沉淀法制备超细Y_2O_3反应条件对粒度的影响

用共沉淀法制备超细Y2O3,研究了料液浓度、复合分散剂和体系反应温度对粒度的影响。在硝酸钇溶液中,加入PVA和SDBS分散剂,以NH4HCO3为沉淀剂,得到碳酸钇前驱体,过滤,120℃干燥,在700℃灼烧3h,制备出了分散性好、平均体积粒径为97.5nm的超细Y2O3粉体;得到了在硝酸体系中制备超细Y2O3的最佳工艺条件:硝酸钇的浓度为0.3mol/L,复合分散剂加入量3%,体系反应温度50℃~60℃。     

湿固相机械化学法制备超细氧化钇的研究

以工业上常见的水合草酸钇和氨水为原料，采用湿固相机械化学法制备了D50〈0．5μm，D50〈μm的窄分布超细氧化钇，研究了在球磨和煅烧过程中对氧化钇粒度的影响因素，通过粉末X射线衍射（XRD）、同步热分析（TG-DSC）和傅立叶变换红外光谱（FTIR）考察了球磨过程中的机械化学反应与物相转变，以及前驱体的热分解过程。     

Morphology controllable synthesis of yttrium oxide-based phosphors from yttrium citrate precursors

A novel yttrium citrate-templated conversion method for morphology controlled synthesis of Y2O3 microspheres, microflowers and microsheets was reported for the first time. The precursors with controllable morphologies were synthesized with a homogenous precipitation method in aqueous solution without any surfactant. Y2O3 samples with well-preserved morphological architectures were obtained by a subse-quent thermal transformation strategy. The chemical formula of the precursor was identified and a two-stage ...     

Preparation of nanoscaled yttrium oxide by citrate precipitation method

The nano-Y_2O_3 was prepared from YCl_3 by the citrate precipitation method. The precursor powders were prepared by 0.1 mol/L YCl_3 solution and 0.1 mol/L hydrochloric acid in the presence of 1% surfactant PEG2000, which was dried via an ethanol azeotropic distillation method. The effects of reaction temperature, precursor concentration, hydrochloric acid concentration, surfactant, and calcination temperature on the mean sizes of nano-Y_2O_3 were studied. It was found that the highest yield of precursor was about 70% at the p H value of 5.0, and the yield decreased rapidly at the p H value below 4 or over 6. The reaction temperature revealed no effect on the size of precursor. The optimized precursor concentration and hydrochloric acid concentration were both 0.1 mol/L. Several typical analytic techniques such as particle size analyzer, X-ray diffraction(XRD), thermogravimetric and differential thermal analyses(TG-DTA) and scanning electron microscopy(SEM) were used to determine the characteristics of the prepared nano powders. Homogeneous torispherical nano-Y_2O_3 with the smallest size(20 nm) could be obtained by calcining the precursor powders at 800 oC for an hour.     

Preparation of titanium oxide powder of prescribed composition

A mathematical model is suggested for the process of titanium chip impregnation with oxygen. The model is based on the assumption that it is possible to ignore the effect of a thin surface oxide film on oxygen impregnation of -Ti solid solution. The process of producing TiO powder with a particle size of less than 100 µm has been optimized for the minimum expenditure of energy.Institute of Fine Chemical Technology, Moscow. Translated from Poroshkovaya Metallurgiya, No. 2(362), pp. 11–15, February, 1993.     

Effect of yttrium oxide volume fraction and particle size on elevated temperature strength of a dispersic strengthened superalloy

The effect of yttrium oxide dispersoid volume fraction and particle size on the 1400†F (1033 K) and 1900†F (1311 K) rupture strength of a dispersion strengthened nickel-base superalloy, made by mechanical alloying, was investigated. Yttrium oxide Contents ranged from 0 pct to 4.5 pct by volume, and average oxide particle sizes varied from about 150Å (15 nm) to 580Å (15 nm) to 580Å (58 nm). High volume fractions and small particle sizes gave low grain aspect ratios and poor 1900†F (1311 K) and 1400†F (1033 K) stress rupture properties following heat treatment. Rupture strengths at 1400†F (1033 K) were otherwise relatively unaffected by dispersoid parameters. At grain aspect ratios less than 6.0, 1900†F (1311 K) rupture strength was controlled by grain geometry while at higher values rupture strength was directly influenced by dispersoid parameters.     

带式无舟皿连续还原炉制备粒度均匀的细颗粒钨粉

细晶粒、超细及纳米硬质合金的用途越来越广泛,制备粒度均匀的细钨粉是制备此类合金的关键.本试验研究以工业蓝色氧化钨和超细黄色氧化钨为原料,在带式无舟皿连续还原炉中用氢气还原制备钨粉.试验结果表明,采用带式无舟皿连续还原炉,以蓝色氧化钨为原料制备的细颗粒钨粉粒度均匀性明显优于四管炉生产的钨粉;以超细黄色氧化钨为原料可制备出粒度均匀、氧含量低、比表面在3.5 m2/g左右、粒度为90 nm左右的纳米钨粉;钨粉性能主要受还原温度、氢气流量、钢带传动速度及料层厚度等工艺参数的影响.     

Highly transparent ytterbium doped yttrium lanthanum oxide ceramics

To prepare ytterbium doped lanthania yttria nanopowder a method of laser evaporation of mixed oxides was used. After calcinations of the powder at 1200 °C a pure single-phase solid solution Yb3+:(LaxY1–x)2O3 was formed in the nanoparticles. Influence of lanthanum oxide as an isovalent additive on the yttria structure was investigated. The lanthanium ions were proved to be a good aid to sinter yttria ceramics doped with Yb3+ at moderate temperatures about 1650 °С. The ceramics with relative density higher than 99.99% and grain size about 40 μm were fabricated. Full transmittance of 1.8 mm thick Yb0.11La0.23Y1.66O3 ceramics reached 82.5% at 800 nm. This material could be a good gain medium for ytterbium high power pulse lasers.