西北有色金属研究院研制成钨钼复合旋转靶

<正> 西北有色金属研究院粉末冶金研究室科技人员经过两年多努力,攻克了钨和钼压制分层等技术难关,研究出钨钼复合旋转靶。这种靶系医用 X 光管的阳极,是纯钨靶的换代产品,一直依靠日本进口。经用户装管试验证明,钨和钼形成了很好的冶金结合,牢     

旋转阳极钨靶及钨复合靶的性能和应用

一、前言医用 X 射线管的旋转阳极比老式的固定阳极具有焦点小、功率大、散热快和可长期工作等优点。早期的旋转阳极采用纯钨作靶面。由于对阳极材料在耐高温、高功率和散热快方面提出了更高的要求,六十年代以来,国外相继发展了钼基和石墨基钨(或钨合金)复合靶。我们根据国内医疗器械工业的需要,于1976年采用粉末冶金-变形工艺,研制成功不同规格的变形钨靶。变形钨靶具有密度高(>19.2克/厘米~3),强度高,能经受高速旋转(～3000转/分)及寿命长等优点。把制成的φ70和φ90变形钨靶,装入20/40-125和30/50-125旋转阳极 X 射线管,进行全面性能检验及临床考验。结果证明,变形钨靶性能稳定,因此已批量生产并供医院临床使用多年。继之又研制成功钨-石墨复合靶,为发展高转     

用D2EHPA和LIX63萃取钼和钨

<正> 一、前言钼和钨在水溶液中以多种离子形式存在,在较广的pH范围内,钼和钨均以单核及多核阴离子形式溶解,更确切地说在pH3—6范围内钼和钨形成复合多核阴离子。这就是在此pH范围内钼和钨难以分离的原因。然而,在强酸性水溶液中,钼主要是以MoO_2~(2+)、钨主要以H_3W_6O_(21)~(3-)的形式存在,因此,可用阳离子交换型的萃取剂来萃取分离钼和钨。 Esnault曾用二(2-乙基已基)磷酸(D2EHPA)研究了分离钼和钨的方法。但当钨浓度高时,钼的萃取率下降,因此,只能在钨浓度较低的溶液中用D2EHPA分离钼和钨。通常人们认为只有用比D2EHPA萃取能力更强的萃取剂时,才能从含钨浓度高的溶液萃取分离钼。     

从钼氧化物中去除钨的新方法

日本一家公司研究出一种从三氧化钼中分离钨 ,制取高纯钼粉的新方法 ,以满足钼溅射靶对原料纯度越来越高的要求。在一般的纯钼粉中 ,含有10 0～ 2 0 0ｍｇ/ｋｇ的钨 ,这种钼原料中钨的去除非常困难 ,虽然实验室中有一些净化方法 ,但未能用于工业生产。新方法容易分离三氧化钼中的钨 ,并能进一步清除其它杂质。这种新方法是 :用无机酸调节含钨的钼酸铵溶液至酸性 (ｐＨ值为 2 .5～ 4 .5 ) ,使钼酸铵结晶首先析出 ,与氧化钼的钨分离。采用这种方法 ,能使钼氧化物中钨的含量降至 10ｍｇ/ｋｇ以下 ,其它杂质的含量也大大减少 ,从而提高钼粉的质…     

钼冶金中钼钨分离工艺述评及探讨

钼冶炼过程中钼钨分离是一个亟待解决的技术难题,本文概述了钼、钨化合物性质上的差异,并对目前公开的方法如酸沉法、萃取法、物理吸附法、沉淀法及离子交换法进行了综述及实验验证,对这些方法分离钼钨的原理、工艺及效果进行了总结及评价,提出了今后钼钨分离研究方向。     

小波分析与蚁群神经网络5′-硝基水杨基荧光酮分光光度法同时测定钨钼锑

提出了钨、钼、锑-5′-硝基水杨基荧光酮-CTMAB的新显色体系,并用于钨、钼、锑三组分光度分析。为解析钨、钼和锑的重叠光谱,提高多组分同时测定的准确度,将蚁群神经网络(ACAN)与小波分析相结合,建立一种利用小波变换提取重叠光谱信息,再用蚁群神经网络解析的方法,此方法应用于合金钢标准样品中钨、钼、锑多组分同时测定,测定值与认定值相符,相对误差分别为0.14%、0.13%、0.013%。     

水杨基荧光酮-CTMAB分光光度法同时测定钨和钼

水杨基荧光酮－ＣＴＭＡＢ分光光度法同时测定钨和钼侯明,黄诚（桂林工学院应用化学系,桂林,５４１００４）在阳离子表面活性剂存在下,利用水杨基荧光酮作为显色剂分别测定钨［１］、钼［２］已有报道,但由于钨、钼的吸收光谱重叠,相互干扰严重。目前报道的方法只适...     

电感耦合等离子体原子发射光谱法测定除钼渣中的钨

针对除钼渣中的钨含量测定存在现有操作方法繁琐,易受钼干扰的问题,研究提出了ICP-AES分析方法,分别研究了不同酸分解除钼渣的方式,考察了硫酸-磷酸混合酸的不同用量对仪器测定的影响,对钨最佳分析谱线和发射功率进行了选择,考察了高含量钼及其他杂质元素对钨的干扰情况,与其他分析方法进行了比对,结果显示ICP-AES测定钨能够满足要求。该方法能对试样进行精密度测定,方法的相对标准偏差RSD<2%,回收率可以保持在98%~102%之间。实验表明该方法操作简便、结果准确、干扰少,适用于除钼渣中钨的日常测定。     

从废灯芯中回收钼和钨

<正> 废灯芯含有价格昂贵的钼和钨。英国弗莱特等人对含钼高达120(克/升)、钨1(克/升)、总酸度约12N 的废灯芯酸进行试验研究。他们用1M 酸性萃取剂二-2-乙基己基磷酸(D-2-EHPA)萃取钼和钨,     

钨钼工艺分离的前景

钨钼分离有效方法的研究是从钨精矿和二次钨原料制取纯三氧化钨工艺的迫切任务.这一点是由一系列情况所决定.用户对用来生产金属的三氧化钨纯度提出很高的要求,特别是其中钼的含量不应超过0.02%。而钨精矿及二次原料大部分含有较高的钼。     

Microstructure and properties of molybdenumprinciple-copper composite metal samples consolidated by plasma pressure compaction

Abstract

In this study, a composite metal powder mixture using molybdenum and copper powders was consolidated tonear theoretical density using the rapid consolidation technique of plasma pressure compaction. Rapid consolidation of the mixture of metal powders is an essential requirement for better microstructural control and mechanical properties in the consolidated product. The microstructure and hardness of the composite samples are compared with monolithic samples made by consolidating pure molybdenum powders under identical conditions. Microhardness measurements revealed an increase in hardness of molybdenum when mixed with small amounts of copper. The role of consolidation parameters on hardness and microstructural development is presented and discussed.     

Effect of Molybdenum Additions on Compaction during Sintering of Fine-Grained Iron-Copper Pseudoalloys

The effect of added molybdenum powder on compaction and the properties of sintered fine-grained iron-copper pseudoalloys is studied. The original powder mixtures are prepared by mechanical alloying, and the original powder particle size in mixtures does not exceed 0.5 μm. Specimens are sintered in the range 600-1130°C. It is shown that addition of molybdenum powder to the original charge accelerates compaction of fine pseudoalloys in both the solid phase and liquid-phase sintering compared with compaction of the same pseudoalloys without adding molybdenum. After solid-phase sintering the maximum relative density of specimens is 98.8%, and after liquid-phase sintering it is 99.3%. The main reasons for acceleration of compaction are prolonged retention of a fine-grained structure of sintered specimens up to the melting temperature for the phase based on copper and mutual diffusion between iron and molybdenum; to a significant extent the latter occurs during specimen heating in the solid phase.     

掺杂方式对Al2O3/Mo复合材料组织及性能的影响

分别采用固-固、液-固和液-液掺杂方式向钼粉中引入Al2O3,然后用粉末冶金法制备出掺杂钼粉,经压制、烧结制成Al2O3颗粒增强钼基复合材料.对掺杂钼粉及钼坯进行SEM形貌观察,并测定复合材料的密度和显微硬度.结果表明,液-液掺杂能够制备出粉末颗粒小、密度及硬度高的Al2O3/Mo复合材料,其掺杂Al2O3颗粒细小且分布较均匀.     

High-productivity equipment of the rotary type for compacting semiconductor instrument components

The technology for producing high-fluidity molybdenum powder (86 sec) developed previously by the authors makes it possible using traditional methods of powder metallurgy, and in particular cold compaction in steel molds, to produce molybdenum compensators for semiconducting diodes. Rotary high-productivity equipment intended for compacting particularly small articles equipped with a system for individual metering of molybdenum to fill the die is developed and put into practice. A stepwise form for the punch working zone is suggested for obtaining the required outer radius of curvature. The efficiency of the rotary machine is at least 2400 articles per h with a maximum compaction force of 50 kN.Translated from Poroshkovaya Metallurgiya, No. 11(359), pp. 28–32, November, 1992.     

The process of compaction of molybdenum disilicide

Summary A study was made in this investigation of the influence exerted by the time of holding of powder under load, repeated compaction, percentage moisture content, and plasticizer on the compressibility of molybdenum disilicide. In addition, the distribution of forces during compaction and the elastic recovery of compacts were examined.The density of a molybdenum disilicide compact is independent of the time of holding under load, and, consequently the compaction process may be carried out practically instantaneously. It is desirable to employ double or treble compaction with intermediate rubbing through a sieve, the first compaction being performed at a pressure of 35–40 kN/cm² and the second at a pressure of 15–25 kN/cm².It was established that the compaction of molybdenum disilicide is described by semilogarithmic functions of compaction pressure and relative volume. The constants of these equations were determined.The optimum moisture content for the compaction of MoSi₂ powder is 1–3%, and the optimum amount of bentonite addition 3–4%.The use of punch face and die wall lubrication reduces friction between the powder and the die walls, thereby increasing the density of the compact.The minimum elastic recovery (0.4%) is observed at a compaction pressure of 20 kN/cm².The author thanks G. V. Samsonov, Corresponding Member, Acad. Sci. UkrSSR, for his assistance in a number of problems which arose during this investigation and evaluation of the results obtained.     

Effect of Compaction Scheme on Property Distribution for Cumulative Charge Facings Formed from a Heterogeneous Powder Composite

An experimental and numerical (finite element method) study is carried out for the effect of forming scheme on property distribution for cumulative charge facings made from composite heterogeneous powder material. An experimental procedure is developed for studying powder particle flow kinetics. It is shown that use of composite punches and partition of the moulded material into a number of sub-divisions with their successive compaction achieves a more uniform density distribution for an article. It is demonstrated how the direction of the force of friction on the die walls during compaction affects the compaction of articles with faces that are not perpendicular to the direction of the pressing. The results obtained make it possible to select the optimum compaction regime taking account of production features connected with powder material composition as well as service characteristics.     

Effect of Compaction Scheme on Property Distribution for Cumulative Charge Facings Formed from a Heterogeneous Powder Composite

An experimental and numerical (finite element method) study is carried out for the effect of forming scheme on property distribution for cumulative charge facings made from composite heterogeneous powder material. An experimental procedure is developed for studying powder particle flow kinetics. It is shown that use of composite punches and partition of the moulded material into a number of sub-divisions with their successive compaction achieves a more uniform density distribution for an article. It is demonstrated how the direction of the force of friction on the die walls during compaction affects the compaction of articles with faces that are not perpendicular to the direction of the pressing. The results obtained make it possible to select the optimum compaction regime taking account of production features connected with powder material composition as well as service characteristics.

     

球磨工艺对Al2O3/Mo复合材料组织的影响

针对原位自生Al2O3增强钼基复合材料晶粒较大的问题,采用溶胶-凝胶与高能球磨相结合的方法细化复合材料晶粒,并利用SEM、XRD对不同球磨工艺所制备Al2O3/Mo复合粉末及复合材料的组织进行了观察和分析。结果表明:随着球磨时间的延长,Al2O3/Mo复合粉末颗粒由球状变为层片状再成为细小的球状,颗粒大小由约1.5μm细化为约500nm,其中的钼晶粒不断细化;高球料比所得粉末的分散性和破碎细化程度较好;转速提高使得粉末颗粒的尺寸均匀程度降低,且伴有结块现象,不利于粉末的细化。在球料比5∶1、转速300r/min、球磨时间60h条件下获得的复合粉末,经压坯烧结可制备出Al2O3颗粒为纳米级的钼基复合材料。     

zrc对等离子喷涂成形钼制品的影响

采用包覆法制备了Mo-ZrC复合粉末,采用等离子喷涂成形,再对其进行热等静压处理得到复合材料零部件.将其与纯钼粉末等离子喷涂成形零部件作对比.用阿基米德法测量两种零部件的相对密度；用显微硬度计测量它们的维氏硬度；用万能材料试验机测试它们的拉伸强度；用扫描电镜观察它们的截面和拉伸断口微观形貌.结果表明,加入的ZrC在基体中呈弥散分布,且分布均匀,填充了钼颗粒之间的部分空隙.纯钼材料拉伸断口呈沿晶断裂,而复合材料的拉伸断口出现了部分穿晶解理断裂.纯钼材料的相对密度为86.5％,拉伸强度及显微硬度都较低.而复合材料的相对密度为89.7％,力学性能有显著提高,拉伸强度提高到123 MPa,显微硬度提高到275 HV0.025.     

我国穿甲弹用钨合金研究的最新进展与展望

综合介绍了我国近年来对穿甲弹用高密度钨合金实施添加微量元素合金化强化和旋转锻造、扭转变形、静液挤压等形变强化的研究进展，以及对于绝热剪切机理和数值模拟计算的研究现状，并介绍了机械合金化制备纳米钨合金复合粉末、温压成形及预氧化活化烧结等特种制备技术方面的最新试验研究进展。通过全面分析目前我国穿甲弹用高密度钨合金试验研究中存在的一些主要问题，提出我国穿甲弹用高密度钨合金今后研制的主攻方向，以及促进高性能穿甲弹用钨合金研制应采取的策略与措施。