出水支管铸件的熔模铸造工艺优化

为了提高出水支管熔模铸造的铸件质量,利用ProCAST软件进行了浇注系统设计及优化。模拟了浇注温度、浇注时间和型壳预热温度对铸件凝固过程的影响。经过多次模拟,得到了最佳工艺参数,即浇注温度1350℃、浇注时间6 s、型壳预热温度500℃。使用优化工艺参数得到的铸件避免了缩松缩孔等缺陷。     

离心泵壳铸造凝固过程应力场模拟

针对大型不锈钢泵壳砂型铸造工艺开展研究,应用ProCAST软件进行模拟,比较了不同浇注时间(100s、120s、140s)和不同浇注温度(1530℃、1580℃、1630℃)下的应力场分布,对比充型时间和浇注温度对铸件有效应力的影响,并对可能产生热裂的部位进行预测,避免铸件产生裂纹,从而获得符合要求的泵壳铸件,数值模拟技术的合理应用有效减少了时间和成本。     

抗氧化钢铸件的熔模铸造工艺

阐述熔模铸造抗氧化钢铸件的工艺特性，通过对型壳的焙烧温度、保温温度、保温时间、浇注温度和钢水浇注温度等工艺参数的生产过程控制，提出浇壳比理论，克服薄壁件和壁厚悬殊件的开裂、缩孔、疏松等铸造缺陷，从而增加铸件的热强性能，提高抗高温氧化腐蚀性能，延长抗氧化钢铸件在高温工作状态下的使用寿命。     

铝合金缸盖铸造工艺参数优化

金属型重力铸造的浇注方式和铸造工艺参数,如浇注温度、浇注时间和模具温度是影响铸件质量的重要因素。在金属型重力铸造中,可以通过改变这些工艺参数,达到提高铸件成品率的目的。运用MAGMA软件对金属型重力铸造铝合金缸盖的铸造过程进行数值模拟。分别采用顶注和底注方式,以及铸造工艺参数(浇注温度、浇注时间和模具温度)的正交试验方案,优化了缸盖铸件铸造工艺参数。采用优化后的铸造工艺方案,铝合金缸盖铸件合格率达到98%。     

基于ProCAST连接箱回油座工艺优化

使用有限元软件ProCAST对灰铸铁连接箱回油座熔模铸造过程进行了模拟,研究了浇注温度、浇注速度以及型壳预热温度三个参数对铸件缺陷的影响。结果表明,当铸造充型时间3.5 s时,在浇注过程中容易产生缺陷。通过优化熔模铸造工艺,获得的较优工艺参数为:浇注温度1397℃,浇注速度350 mm/s,预热温度1000℃。在这个工艺参数下,铸件缺陷得到消除,熔模铸造质量得到提高。     

高性能锡青铜叶轮铸件的研制

针对当前锡青铜叶轮铸件组织比较疏松、强度低等特点结合叶轮铸件的结构特点,制定了切实可行的工艺路线,采用新型合金、熔模制壳、真空熔炼、离心浇注等工艺措施,确定了熔炼温度、浇注温度、离心转数等相关工艺参数,获得了表面及内部质量均合格的铸件。     

精密铸造0Cr17Ni4Cu3Nb不锈钢航空发动机零件

基于数值模拟分析技术,采用正交试验和试验验证对熔模铸造ZG0Cr17Ni4Cu3Nb不锈钢航空发动机尾部搭接件中的缩孔进行了分析,研究了浇注温度、浇注速度和铸型温度对缩孔体积的影响。结果发现,浇注温度对铸件缩孔影响最大,其次是型壳温度。结合数值模拟对该铸件的浇注系统进行了优化。通过实际浇注试验对模拟结果进行验证,并试制出了合格的铸件。优化后的工艺方案:左右两侧的内浇口对称布置,浇注温度为1 560℃、浇注速度为320mm·s~(-1)、型壳温度为920℃。     

熔模精密铸造冷型浇注研究

本文对熔模精密铸造的冷型浇注进行试验研究。试验表明:熔模精密铸造型壳采用冷型浇注,可防止碳钢及低合金钢铸件的表面的氧化脱碳,有利于提高铸件的表面硬度;并可防止或减轻铸件表面的化学粘砂缺陷。试验中对型壳层在浇注后的温度分布进行了测定,对冷型壳的升温及应力变化规律,以及对型壳强度的影响进行了分析;并探讨了铸钢件表面化学粘砂机理。     

基于ProCAST的大型薄壁机匣件整体熔模铸造工艺研究

为了实现大型薄壁机匣件的整体熔模铸造和获得高质量的铸件,运用ProCAST软件对一种大型薄壁机匣件的整体熔模铸造工艺方案进行数值模拟,通过对充型、凝固过程以及温度场分布的分析,发现浇注后的铸件在内、外环侧面及支板的根部易出现缩孔、缩松缺陷.经过优化设计,通过采取在浇注系统浇冒口处包裹保温毡和提高型壳预热温度等措施,较好地避免了上述铸造缺陷的产生,提高了成品率,获得了较高致密度的机匣铸件.     

精密熔模铸造气门座圈缩孔缺陷及改进措施

对4G22发动机气门座圈在生产过程中出现缩孔缺陷进行分析,从型壳的制作工艺、铸件的浇注工艺出发,找出缩孔缺陷的产生原因,并提出了相应的改进措施:一是提高型壳的焙烧温度,延长型壳的焙烧时间;二是采用红壳浇注,适当降低冷却速度;三是调整金属液出炉温度及浇注温度;四是适当提高浇注速度,缩短浇注时间。结果显示,改进生产工艺后,缩孔导致的缺陷率由原先的13%左右下降到3%以下。     

球铁管件真空消失模壳型复合铸造工艺的研究

比较了真空消失模铸造和熔模铸造两种工艺的优缺点,将两种工艺的优点有机结合,开发了适应大量生产高性能出口管件的真空消失模壳型复合铸造工艺.介绍了消失模铸造模型刚度的确定、浇注系统尺寸的选择,壳型工艺流程的制订、壳型涂料的原材料选用和配制、以及水玻璃壳型制造流程.试验结果显示:(1)用此工艺生产的管件,工序简单且铸件质最稳定,铸件合格率达到98.5％以上;(2)此工艺只要制4层壳,相比普通蜡模精密铸造制壳要8层以上,提高了生产效率,降低了生产成本和人力资源成本.     

熔模铸造硅溶胶模壳制造工艺

介绍用石蜡-硬脂酸低温模料制作熔模,用硅溶胶作粘结剂制造模壳的工艺。包括熔模制造工艺、硅溶胶模壳工艺和焙烧工艺。生产实践证明,铸造硅溶胶模壳制造工艺是成熟的,为生产合格模壳和精密铸件提供了技术保障。     

Research on cracking mechanism of the thin shell mould in expendable pattern shell casting during pattern removal process

Aiming at the cracking phenomenon of the thin shell mould in the expendable pattern shell casting during the pattern removing process, some systemic researches are presented.The influence of the pattern removing method and temperature on the pattern removing were investigated.The shell mould cracking mechanism was analyzed by using thermo-gravimetric analysis (TGA), and combining the temperature field and the volume change of the expanded polystyrene (EPS) foam pattern being tested.The results indicated that the shell mould was not easily cracked when the pattern removing process was carried out with the furnace being heated little by little because of the shell slowly shrinking with dehydration and shell strength gradually increasing.The shell mould was soon destroyed when it was set directly into the furnace at above 400 oC because of the thin shell mould rapidly shrinking and the foam pattern hindering.However, the shell mould had no cracking when it had been preheated for a long time even if the furnace temperature was above 400 oC and the shell was put into the furnace directly.Moreover, when the shell mould was directly set into the furnace at lower temperatures, 250 to 300 ℃, the shell would shrink slowly and the foam pattern would stay at the maximum expansion stage temperature of 100 to 110 ℃ for a long time; and the shell mould would experience an expansion force from the foam pattern for a long time.The expansion force is related to the pattern removing temperature, holding time, foam pattern thickness and density.Therefore, the foam pattern with higher density could make the shell crack.     

精密铸造硅溶胶模壳的制造工艺

介绍用石蜡-硬脂酸低温模料，生产铸件的熔模和用精密铸造硅溶胶，作为制壳粘结刑，制造铸件的模壳的工艺要求。主要研究熔模制造工艺、硅溶胶模壳工艺和焙烧工艺。五年多来的生产实践充分证明精密铸造硅溶胶模壳制造工艺是成熟的。为生产合格模壳和精密铸件提供了技术保障。     

完善首饰精密铸造模型的工艺实践

在利用精密铸造进行批量生产首饰过程中,首饰模型的制作过程是最基本、最重要的生产环节。研究了用硬蜡雕刻首饰原模型至首饰蜡模树的熔接过程中,易出现问题及解决措施。通过大量的实验验证,指出了利用首饰原模型硫化橡胶模具操作中最适合的温度、压力及时间参数,利用真空注蜡机把液态蜡注入首饰橡胶模具时,根据首饰设计的复杂程度,应选择不同工艺参数等问题,为完善首饰精密铸造模型提供了重要依据。     

农机小齿轮及齿圈的精铸工艺

采用中温蜡料、硅溶胶型壳的精铸工艺生产农机用碳钢小齿轮及齿圈.介绍了铸件生产的技术难点、生产条件、模具设计、制壳、熔炼及浇注工艺.经验证,生产的铸件质量好,废品率低,可直接用于装配,说明该工艺合理可行,不仅提高了材料的利用率,降低了生产成本,还提高了生产效率.     

Casting of microstructured shark skin surfaces and possible applications on aluminum casting parts

Within the project "Functional Surfaces via Micro-and Nanoscaled Structures" which is part of the Cluster of Excellence "Integrative Production Technology" established and financed by the German Research Foundation (DFG),an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1μm on near-net-shape-casting parts has been developed.The common way to realize functional microstructures on metallic surfaces is to use laser ablation,electro discharge machining or micro milling.The handicap of these processes is their limited productivity.The approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master pattern.The main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding accuracy.Actual results concerning making of the wax pattern,suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are presented.By using of the example of an intake manifold of a gasoline race car engine,a technical shark skin surface has been realized to reduce the drag of the intake air.The intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin riblets.For this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part.A technology for the fabrication and demoulding of accurate microstructured castings are shown.Shrinkage factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well.     

An alternative approach in ceramic shell investment casting of AZ91D magnesium alloy: In situ melting technique

In this research, the possibility of ceramic shell investment casting of a magnesium alloy using in situ melting technique was explored. AZ91D granules were charged into shell investment mould and in situ melted under various processing parameters including heating temperature, flux application, shell mould thickness and permeability. Scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction techniques were used to characterise the cast samples. Thermal analysis was employed to further investigate the effect of mould thickness on the solidification behaviour of the metal. It was found that mixing flux with the granules not only reduced the temperature at which melting can be achieved, but it also contributed to produce castings with acceptable surface quality. The use of thinner mould provided higher solidification rate, which is believed to favour in situ melting of the granules. It enabled melting of the granules at 650 °C, which in turn helped to suppress the mould–metal reaction and produce castings with good surface quality. Shell mould permeability showed no influence on suppressing the mould–metal reaction at 650 °C.     

玻璃模快速制造工艺

对客户提供的玻璃器皿样品尺寸进行三坐标测量,在此基础上利用快速成形技术对样品进行三维造型并制成样品的树脂原型。利用石膏模和与样品相同尺寸的树脂原型制作模具毛坯的型芯,采用中空的毛坯木模来造型,可以实现玻璃模具毛坯的快速铸造;利用ZrO2熔模和将样品的尺寸放大1mm的树脂原型来制作模具电火花加工的电极,以补偿样品生产时的收缩。用这种工艺可以快速得到模具毛坯和电极,实现玻璃模具的快速加工。     

An integration system for investment casting mould design of aeroengine turbine blade

An integration system was developed to satisfy the need of information integration in the process of designing, investment casting and monitoring aero-engine＇s turbo blade. The general architecture is detailed presented in this paper. The system mainly comprises of product master model, design information management, anti-deformation design of mould cavity, intelligence mould design and blade testing. The developed system can manage mould design and blade test data flow, optimize mould design process and achieve the goal of integration design.