Zirconium Dodecaboride-based cutting material

Samples of zirconium dodecaboride are obtained by means of arc and induction melting of a mixture of zirconium and boron powders. A solder for binding the zirconium dodecaboride to the steel holder of the tool is selected. It is established that cutting tools supplied with zirconium dodecaboride may be used in operations of finish turning of adhesive-active titanium alloys.     

切削不同铸铁材料的PCBN超硬材料刀具磨损研究现状

基于聚晶立方氮化硼(PCBN)超硬材料刀具的高硬度、良好的耐磨性及化学稳定性,其在汽车制造领域的应用变得越来越广泛。对国内外学者们使用PCBN超硬材料刀具加工灰铸铁、球墨铸铁和蠕墨铸铁的研究现状进行总结分析,主要从刀具材料、工艺参数、工件材料、切削环境及加工方式等几个方面对PCBN超硬材料刀具切削加工3种铸铁时的磨损机制进行讨论,最后总结了切削不同种类铸铁材料时刀具的磨损情况。     

碳化锆碱熔制备氧氯化锆的研究

以碳化锆为原料，采用碱熔一水洗一酸浸．结晶工艺制备氧氯化锆，制得的氧氯化锆产品中ZrO2含量达到36．20％。考察了氢氧化钠与碳化锆物料比、碱熔温度、碱熔时间和碳化锆粒度对碱熔过程中锆转化率的影响，以及水与碱熔料比、水洗温度和水洗时间对水洗过程中除硅率的影响。用X射线衍射分析研究了碳化锆在煅烧碱熔过程中的物相变化。结果表明，碱熔过程中碳化锆转化为偏锆酸钠，碱熔的最佳工艺条件为：氢氧化钠与碳化锆的质量比为1.5，煅烧温度800℃，煅烧时间60min，矿样粒度120目。在该工艺条件下碱熔，锆的转化率可达到99％以上。     

大型法兰下料拼焊及外包哈氏合金焊接

贵溪冶炼厂硫酸车间净化工序中动力波溢流堰与烟道过渡段采用了哈氏合金G-30进行贴补防止腐蚀。本文主要介绍了过渡段法兰的数控下料和焊接变形控制措施,通过对外包哈氏合金的化学成分分析,制定合理焊接工艺和方法,保证了焊接质量,满足了生产需要。     

包覆浇铸和热轧工艺制备Q235/CrWMn刀具材料

通过包覆浇铸+热轧变形工艺,制备了Q235/CrWMn钢复合刀具材料,并用扫描电子显微镜(SEM)和维氏硬度仪分析了复合材料的界面组织、成分和性能的变化规律.实验结果表明,通过真空冶炼浇铸以及变形量超过90%的热轧工艺,可以实现两种组元金属材料之间的冶金结合,其中Cr、W等元素的过渡层宽度仅为10～40μm.随后的热处理研究发现,复合材料在830±5℃保温后空冷或者油淬时,Q235一侧为珠光体+铁素体组织,CrWMn一侧为马氏体组织,其硬度可达600～750HV,使复合刀具材料同时具有较好的韧性和强度.     

我国锆材料现状及江西锆业发展思路

简要介绍了锆铪资源的分布、特点，在国民经济和国防建设中的意义；重点叙述了我国锆铪工业的发展历史、锆材料现状以及锆铪产品与锆铪产品的生产工艺、技术水平，锆铪材料贸易及应用前景，同时，介绍江西锆业状况与今后的发展思路。     

锆的燃烧与防护

核电是我国能源长期发展规划中明确提出的大力发展的行业,它将带动我国核级锆材产业的大发展.介绍了锆是一种高熔点的活性金属,具有引燃能量低,粉尘能自爆,能与氮、二氧化碳反应燃烧,潮湿更易燃烧和能引燃各类物质等特性.综述了锆的燃烧扑灭方法以及预防燃烧和爆炸的具体措施.     

锆合金研究进展及我国核电站用锆材国产化的思考

综合评述了国内外核电站用锆合金材料的研究进展,重点介绍了目前国际上发展成熟的高性能锆合金：法国的M5合金、美国的Zirlo合金、俄罗斯的E635合金、日本的NDA合金及韩国的HANA合金。分析了我国在核电站用锆合金材料研制过程中存在的问题,以及我国核电用锆材国产化的难点。对我国核电用锆材的发展思路提出了几点建议。     

Features of Production and High-Temperature Oxidation of SHS Ceramics Based on Zirconium Boride and Zirconium Silicide

This article is devoted to the investigation into the combustion kinetics and mechanism of reaction mixtures in Zr–Si–B and Zr–B systems formed according to the forced SHS-pressing of compact ceramic materials, as well as to studying their heat resistance. It is shown that dependences of the combustion temperature and rate on the initial temperature (T₀) for compositions in the Zr–Si–B system are linear; i.e., staging of chemical reactions of formation of zirconium diboride and disilicide remains invariable with an increase in T₀. The values of effective activation energy of SHS process, which evidence the leading role of the reaction interaction of zirconium with boron and silicon in the melt, are calculated. Staging of chemical transformations in the combustion wave of the Zr–Si–B system is investigated: initially the ZrB₂ phase is formed by crystallization from the melt, and then the ZrSi₂ phase appears with a delay of 0.5 s; unreacted Si crystallizes after 1 s. The phase composition of synthesis products, in which the main component is ZrB₂ diboride, and zirconium disilicide, Si, and ZrB₁₂ boride are contained depending on the composition of the reaction charge, is investigated. Compact samples having high hardness and low residual porosity are fabricated according to forced SHS-pressing technology. High-temperature oxidation of SHS samples results in the formation of SiO₂–ZrO₂–B2O₃ oxide films and ZrSiO₄ complex oxide on their surface depending on the composition, which serve the effective diffusion barrier and lower the oxidation rate.     

ICP-AES测定金红石中的锆

采用全谱直读电感耦合等离子体发射光谱法测定金红石中锆的含量,方法的检出限为0.02μg/mL,回收率为96.50%~101.00%,相对标准偏差锆为2.62%,测定结果令人满意,方法简捷、快速、可信。     

Zirconium alloys dispersion strengthened with yttria

Abstract

A powder metallurgy process for the manufacture of zirconium alloys dispersion strengthened with yttria particles is described. The resulting alloys con tain a suitable dispersion of stable yttria particles in a fine-grained matrix. Tensile and stress rupture tests over a range of temperature on Zircaloy-2 containing 0, 5 and 10 vol % yttria show the strength of yttria-containing alloys to be significantly improved. The post-irradiation tensile properties of Zircaloy-2 - yttria alloys have been determined with alloys irradiated at 280°C to 9.2 × 10²⁰ n/cm² thermal and 2.3 × 10²⁰ n/cm² fast. The alloys have been subjected to accelerated corrosion tests in steam and exhibit a variable response. Some possible detrimental factors and means of improvemen t of properties are discussed.

The mechanical properties of Zircaloy-2 alloys containing yttria particles are compared to some other zirconium alloys, Zircaloy-2 and zirconium-2.5 wt % Nb and the comparisons show that the dispersion- strengthened alloys arc worthy of further development.

Résumé

La fabrication par frittage des alliages de zirconium renforcés par des particules d'yttria est décrite. Ce procédé donne une dispersion convenable des particules d'yttria dans une matrice à grains fins. Des essais de traction et d'impact, effectués à diverses températures sur du Zircaloy-2 contenant 0,5 et 10 % d'yttria, ont montré que la résistance mécanique des alliages est nettement augmentée. D.autres essais de traction ont été effectués sur des alliages Zircaloy-2-yttria aprés des irradiations de 9.2 × 10²⁰ n/cm² thermique et 2.3 × 10²⁰ n/cm² rapide à 280°C. Les alliages ont été soumis à des essais de corrosion accélérée (vapeur) avec des résultats variables. Dans la discussion on considère les facteurs qui peuvent être miscibles ainsi que déautres améliorations possibles.

La comparaison des propriétés mécaniques des alliages de Zircaloy-2 contenant de l'yttria à celles d'autres alliages de zirconium, Zircaloy-2 et zirconium-2.5,% Nb indique que les alliages à particules dispersées méritent d'être étudiés davantage.     

Study on Preparation of Zirconium Sulphate

The preparation method of Zr(SO₄)₂*4H₂O was described. It involves following processes zircon fusing with sodium hydroxide, water leaching, sulfuric acid leaching and product crystallized process, etc. The technical factor and the experimental data are given. Among the products, the ZrO₂ content is 34% and impurities are less.     

金属锆制备方法的研究进展

总结了国内外金属锆制备方法.传统方法包括金属热还原法、氢化脱氢法和电解法,但均存在成本高、污染大、操作复杂等问题.指出了直接电脱氧法是一种制备金属单质和合金的新方法,具有成本低,能耗少、污染小、工艺简单的特点,最有希望取代传统的金属锆制备方法.     

硫酸锆制备工艺研究

介绍了氢氧化钠碱熔分解锆英石，经水洗、酸浸出、结晶等制取硫酸锆的工艺流程、技术条件及试验结果，制得的产品含ＺｒＯ２３４％，杂质含量少。     

硫酸锆生产工艺研究

对锆英石生产硫酸锆的工艺进行研究，其主要过程为：碱熔、水洗转型、一次结晶、二次结晶，离心包装。这一独特的工艺方法解决了锆钠分离，锆铁分离和结晶形态等难题，产品质量达到了国内外用户的要求。     

Compactability of Stabilized Zirconium Dioxide Powder

Features of compacting articles from stabilized zirconium dioxide powder synthesized by the sol-gel method, and also their structure and properties are studied. Compaction parameters are determined. It is shown that the relationship between compact density and extrusion pressure may be described by the Bal'shin equation. It is established that parameters of this equation depend linearly on the duration of zirconium dioxide synthesis.