硅溶胶在定向凝固熔模铸件生产中的应用

介绍了定向凝固高温合金铸件生产应用的硅溶胶的品种、涂料配制、壳型制备方法等，并对现用硅溶胶存在问题及发展前景提出看法。     

超级双相不锈钢5A泵壳铸件裂纹缺陷分析与消除

分析了超级双相不锈钢5A泵壳铸件产生裂纹的原因,结果表明,铸件在铸型里缓慢冷却过程中,组织发生了铁素体的共析转变,铁素体相析出了σ相和二次奥氏体相,σ相是泵壳铸件产生开裂的主要原因,收缩应力和热应力的变化加剧了泵壳铸件开裂的倾向。采用热打箱+热装炉工艺或缓慢冷却＋缓慢升温工艺措施,有效地避免了泵壳铸件的开裂。      

制动泵壳金属型铝铸件工艺改进

介绍了制动泵壳金属型铝铸件工艺改进措施和方法。     

熔模铸造型壳用材料研究进展

近年来,随着熔模铸造发展需求的不断提升,我国工业上更多地追求精密铸件,特别是在航空航天领域,这促使着精密铸件向大型化、复杂化、薄壁化、智能化发展,而铸件质量60%与铸造过程中制备的型壳有关。基于此,综述了现阶段熔模铸造型壳用材料的研究进展,从耐火材料、黏结剂、添加剂3个方面总结了其目前的使用和改进情况。介绍了锆系耐火材料、CaO、Y₂O₃及电熔刚玉几种氧化物面层和背层耐火材料熔融石英、高岭土的应用,现阶段耐火材料的选择更多是根据不同的铸件需求来考虑的,耐火材料的搭配使用和复合耐火材料能够更好地提升型壳质量。对硅溶胶、硅酸乙酯、水玻璃3种黏结剂目前遇到的应用问题进行了分析,改进后的硅溶胶得到了更多学者认可,而硅酸乙酯和水玻璃各自有硅溶胶所不具备的优点,根据需求搭配使用更能体现三者各自的优点。总结了添加剂中常用细化剂、消泡剂、矿化剂的作用及其使用情况,现阶段添加剂的使用研究更为重要,合理地使用添加剂对整个制壳过程起到举足轻重的作用。目前我国的智能铸造发展还不是很成熟,尤其是在型壳制备方面,而未来绿色铸造和智能铸造是值得研究的重点方向。     

三维金属微构件的微熔模精密铸造成形

利用微铸造工艺低成本制备具有三维复杂结构的微金属构件是微细加工技术的发展方向之一。文章利用超声细化工艺改进了现有的微熔模铸造铸型,获得了具有纳米微结构的低表面粗糙度（Ra-0.22μm）的微熔模型壳,并实际离心浇注成形了直径仅为100μm,长径比达到200的微细圆丝Zn-4Al合金微铸件,微铸件的表面粗糙度仅为Ra-0.51μm,且成形完整。     

Ti321钛合金轴箱铸件石墨型铸造工艺研究

目的 研究钛合金高铁轴箱铸件采用石墨铸型工艺时,铸件尺寸、成形及内部质量控制技术。方法 通过对高铁轴箱铸件的结构特点进行分析,针对铸件结构复杂、尺寸比较大、铸件成形比较困难、容易变形的特点,开展了铸型结构设计、铸件尺寸控制技术和铸件成形工艺等方面研究。采用多活块组合的石墨铸型,设计底注开放式浇注系统,利用Procast软件对高铁轴箱铸件的浇注方案进行了模拟分析。选用Ti321合金,设定合理的浇注参数,利用真空自耗电极凝壳炉对铸件进行浇注。结果 铸件成形良好,经过热等静压和后精整后的铸件,铸件内外部冶金质量和性能指标,满足客户标准要求,验证了方案的合理性。结论 铸件的计算机模拟对铸件工艺的设计提供了技术支撑,高铁轴箱铸件采用的石墨型浇注工艺比较合理。     

TC4合金陶瓷模粉末冶金工艺研究

目的 研究陶瓷模粉末冶金工艺,通过数据积累指导未来工程化应用。方法 通过氧化钇陶瓷模壳技术,研究构件与铸件的化学成分、力学性能及微观组织。结果 粉末件在包套高度方向上金属收缩率明显大于包套水平方向的收缩率;粉末构件内部质量良好,无夹杂,其致密度达到了99.5%;粉末构件室温力学性能优于同成分铸件,部分室温力学性能达到TC4锻件水平。结论 采用稀土氧化钇面层、硅溶胶铝矾土背层涂料工艺得到的陶瓷型可用于陶瓷型壳粉末冶金工艺;构件尺寸收缩率在每个方向上不是均匀的,和其在包套内放置方向、包套放置方向都有关系;构件晶粒细小均匀,组织为由细小的魏氏体板条α相与相间β相、等轴α相所组成,等轴α相分布不均匀,主要分布在晶界上;其构件室温力学性能优于同成分铸件力学性能,部分性能达到了锻件水平。     

新型网壳结构的应用与发展

本文阐述了组合网壳结构，局部双层网壳结构，预应力网壳结构，斜拉网壳结构及索弯顶等种新型网壳结构的应用与发展，指出了这些新型网壳结构的受力特性和在设计，分析中应注重的若干要点。     

K417高温合金电磁搅拌法真空晶粒细化技术研究

使用X射线衍射分析仪、扫描电镜、电子拉伸试验机、高温金相显微镜研究了在模壳内壁表面的涂层中添加孕育剂铝酸钴和在真空熔铸过程中施加工频旋转电磁搅拌对K417高温合金真空精密铸件凝固组织和性能的影响。结果表明:采用将在真空熔铸过程中施加150 A的工频旋转电磁搅拌和在模壳内壁表面的涂层中添加孕育剂铝酸钴相复合的方法,可以得到晶粒细化至95μm、断面等轴晶比例达到99%的K417高温合金真空精密铸件。当在电磁搅拌和孕育剂作用下将K417高温合金真空精密铸件的晶粒尺寸从3.45 mm细化至95μm,可以使其粗大等轴晶向细小粒状晶转变,(γ+γ’)共晶的尺寸减小,室温和650℃中温的拉伸性能得到明显改善。     

碳壳型核壳结构微波吸收剂的研究进展

随着电子信息技术的发展，微波的应用领域越来越广泛，同时造成的电磁辐射污染也成为全球关注的问题。高效的微波吸收材料已成为解决电磁辐射污染的有效途径之一。以碳材料为壳的核壳结构微波吸收剂不仅可以优化阻抗匹配特性，而且可以调控微波吸收性能，已成为微波吸收材料的研究热点。介绍了核壳结构微波吸收剂的吸波机理，综述了不同结构组成的碳壳型核壳结构微波吸收剂的制备及微波吸收性能，阐述了其结构组成对提高其微波吸收性能的原因，分析了各种碳壳型核壳结构微波吸收剂的优缺点，进一步对核壳结构微波吸收剂的发展趋势进行了展望。     

加Re新型单晶高温合金熔体与Al2O3型壳界面状况研究

对加入Re的新型单晶高温合金与Al2O3型壳之间的界面状况进行了研究。结果表明，在1550℃下，熔融的合金液体不会与Al2O3型壳产生反应，Al2O3型壳是与DD3+2Re(wt%)新一代单晶配合良好的材料。，The boundary condition between Al2O3 mould shell and a new type single crystal superalloy has been investigated. The results show that the melted superalloy does not react with Al2O3 mould shell,and the Al2O3 mould shell is a good kind of material to match the DD3+Re(2%wt) superally.     

From research to cost effective directional solidification and single crystal production—An integrated approach Part B - materials development

Central to the development of the DS and SC processes has been the need to develop the ceramics for the shell mould because of the significantly greater time and temperature exposure inherent in the process and the need to develop ceramic filtration technology for high temperature alloys to improve cleanliness. For Directional Solidifications (DS) it has not been necessary to develop new alloys; certain of the equiaxed superalloys may be directionally solidified successfully without modification. However to exploit the advantages of single crystal technology new alloys have had to be developed.     

矿化剂在单晶壳型中作用机理的研究

研究了在制造单晶叶片的壳型中添加矿化剂提高壳型高温强度的机制。结果表明，在氧化铝壳型材料中加入一种Ａｌ－Ｓｉ系矿化剂，经过合适的高温焙烧后，生成大量稳定的莫来石相，在刚玉颗粒间形成网络，从而使壳率度大幅度提高。     

A study of two refractories as mould materials for investment casting TiAl based alloys

Interfacial reactions between Ti-46Al (at.%) casting and ceramic shell mould made of ZrO₂ and Al₂O₃ were studied using a range of techniques. On the surface of the TiAl casting, a reaction layer as thick as 230 μm was found in the case of the zirconia mould, whereas there was no visible reaction layer for the alumina mould. Electron probe microanalysis indicated that elements of the two kinds of shell moulds diffused into the alloy melt during casting but to different extents. Metallographic analysis, microhardness measurements and composition analysis showed that alumina was stable and suitable for use as shell moulds when casting TiAl based alloys.     

带底深孔空心件热成形工艺改进分析

目的研究带底深孔空心件热成形工艺现状与改进措施。方法介绍分析了目前国内外所采用的新工艺、模具结构,新型润滑剂、强制润滑方法,新型模具材料、制造工艺及应用情况。结果采用压型、预冲孔、冲孔、拔伸工艺及模口导向的效果良好,通过高压将润滑剂从冲头内部流向冲孔冲头前端,可实现冲孔强制润滑,模具材料可用3Cr3Mo3VNb,4Cr2MoVNi,3Cr3Mo3W2V等,并采用表面强化等工艺。结论应用表明,上述改进措施可降低壁厚差,改进产品质量,并减小摩擦,降低成形力,比传统材料及工艺显著提高了模具寿命。最后指出了还需进一步解决的问题。     

A power transducer system for the ultrasonic lubrication of the continuous steel casting

A critical point in the continuous steel casting process exists in the meniscus zone of the cooled mould, i.e., the region in which the steel stream flowing out of the tundish nozzle starts to solidify. This is a critical point because of the sticking that occurs between the solid shell of steel and the mould. In this work, a new system for the ultrasonic lubrication of the continuous steel casting is proposed and experimentally tested. The basic idea is to excite one of the mould's natural vibration modes by means of a distributed ultrasonic source. This source is composed of an array of power emitters, with each of them placed upon an antinode of the mould. An experimental characterization of the vibrational behavior of a square mould was first carried out. The most active resonance modes of the mould were detected with an experimental technique based on a simple impedance measurement. The modal shape of the selected mode, and hence the position of antinodes, was obtained by means of interferometer measurements. Additional experimental investigations were performed by exciting mould vibrations with up to four piezoceramic disks placed on different sets of antinodes. Some positioning criteria to maximize the superposition effect were derived. Measurements were obtained through excitation of the mould with up to four Langevin-type power emitters, designed and manufactured to work at the mould's selected resonance frequency. These measurements have shown that, by increasing the number of emitters, the ultrasonic power transmitted to the mould and, consequently, the maximum available displacement, increases. Other practical advantages of the proposed system are highlighted and discussed.     

The influence of mould pre-heat temperature and casting size on the interaction between a Ti–46Al–8Nb–1B alloy and the mould comprising an Al2O3 face coat

Alumina has been used as a mould face coat material for investment casting titanium alloys for many years; the interaction between the Al₂O₃ and the alloys are exemplified by a hardened layer formed at the alloy interface. In this research, the interaction between the Al₂O₃ face coat and a Ti–46Al–8Nb–1B alloy was investigated by modelling the cooling profile of the mould during casting. The interaction between the mould and metal was identified from the hardened layer thickness and metal/shell interface microstructural changes. Results showed that a high mould pre-heat temperature and large bar diameter will enhance the interaction between the shell and the TiAl alloy. During the casting process, not only was oxygen observed penetrating into the metal through the decomposition of the face coat materials, but also silicon from the backup coat was found to interact with the metal during the casting process.     

XF-Ⅱ型雷管自动装填生产线介绍

文章介绍了公司自行设计的第2代工业雷管自动装填生产线,该生产线由计算机控制,视频监控;除排管、筛排加强帽和收管工序外,其余危险工序无人操作;采用专利技术自动加药装置实现猛炸药和起爆药装药工序不停机自动加药,单次加药量控制在300g以下;生产线配备了公司独立研发的药高检测和废品自动剔除设备;隔离间皮带安装组合模隔离器,控制组合模数量和间距,有效防止殉爆;生产线班产达12万发,操作人员10～12人。     

异形液氮无磁杜瓦的研制

介绍了一种用于高Ｔｃ ＳＱＵＩＤ器件的异形液氮无磁杜瓦。就杜瓦的材料选择，蜡一次成形法新工艺及杜瓦的结构性能进行了详尽地说明。