Precision casting of Ti-15V-3Cr-3Al-3Sn alloy setting

In this research, Ti-15V-3Cr-3Al-3Sn alloy ingots were prepared using ceramic mold and centrifugalcasting. The Ti-15V-3Cr-3Al-3Sn setting casting, for aeronautic engine, with 1.5 mm in thickness was manufactured.The alloy melting process, precision casting process, and problems in casting application were discussed. Effects ofHot Isostatic Pressing and heat treatment on the mechanical properties and microstructure of the Ti-15V-3Cr-3Al-3Sn alloy were studied.

Microstructure of Zn-Al4 alloy microcastings by micro precision casting based on metal mold

Metal mold micron scale precision casting technology was developed successfully,and three-dimension complicated microgear castings in micron scale were produced.Evolvement regularity of microgear castings were observed by optical microscope and scanning electron microscope.Compared with conventional casting,microcasting is characterized by typical nonequilibrium solidification,for example,its grain size can be refined significantly,eutectic structure is transformed from lamellar morphology to rod eutectic,and the ratio of primary phase is increased.This kind of microstructure can promote mechanical properties of microcasting.

Research on the Casting-forging Precision Forming Process of Alternator Poles

The casting-forging combined technique and the closed die forging without flash-less are both new developed material working methods. The former can not only decrease forming operations of forgings, but also increase the material utilization ratio. Therefore, it is applied to produce more complex forgings. The latter is required for forging precise parts without burrs. The alternator pole is a complex forging, which was usually produced by hot forging, upsetting-extrusion or upsetting-extrusion and bending processes. During these processes, not only the forming force is higher, but the material of burrs accounts for 30 percent or so of total required material. And burrs are difficult to remove in the sequential machining process. In accordance with defects exiting in current manufacturing of alternator poles by upsetting-extruding process, such as more material demand, higher forming force and difficulty of next machining, a casting-forging precision process of alternator poles was developed and investigated in this paper. In the process, the pole was formed by two operations. One is the pre-forming operation by casting. The other is the final forming operation by the closed precision forging process. This can not only shorten processes, decrease material and power demand, but also increase precision of forgings. First, the casting blocker was designed considering the casting process and the forging ratio and the mode of deformation. Then the die structure for closed precision forging was designed, and the closing device for forging dies with spring assemblies in order to provide the necessary closing force was also designed. Finally the forming processes was investigated by test and numerical simulation method to optimum process parameters and die structure design parameters. The result can provide basis for applying the process to manufacture poles in practice.

Rapid precision casting for complex thin-walled aluminum alloy parts

Based on Vacuum Differential Pressure Casting (VDPC) precision forming technology and the Selective Laser Sintering (SLS) Rapid Prototyping (RP) technology, a rapid manufacturing method called Rapid Precision Casting (RPC) process from computer three-dimensional solid models to metallic parts was investigated. The experimental results showed that the main advantage of RPC was not only its ability to cast higher internal quality and more accurate complex thin-walled aluminum alloy parts, but also the greatly-reduced lead time cycle from Selective Laser Sintering (SLS) plastic prototyping to metallic parts. The key forming technology of RPC for complex thin-walled metallic parts has been developed for new casting production and Rapid Tooling (RT), and it is possible to rapidly manufacture high-quality and accurate metallic parts by means of RP in foundry industry.

Development and Application of Ti-based Alloy Casting Technologies in the Field of Aerospace

Ti-based alloys have been widely applied in the aerospace field,owing to their outstanding performance.Precision casting can be used to make integrated near-net-shape components with complex thin-walled structures,which will further promote the engineering application of Ti-based alloys. In this paper,the research progress of Tibased alloys,e. g.,high-temperature Ti-based alloys,high-strength Ti-based alloys,TiAl-based alloys,Ti-based matrix composites,and their precision casting technologies are reviewed. In addition,the development directions of Tibased alloys are presented based on the application status of Ti-based alloys in the aerospace field.

Precision forging technologies for magnesium alloy bracket and wheel

Fundamental investigations on precision forging technology of magnesium alloys were studied.As-cast billet prestraining and a new concept of hollow billet were proposed in order to reduce the maximum forming load.A schcme of isothermal forming and the use of combined female dies were adopted,which can improve the die filling capacity and ensure the manufacture of high quality forgings.By means of the developed technique,AZ80 alloy wheel and AZ31 alloy bracket were produced successfully at suitable process parameters and applied in the automotive industries.The results show that the hot compression of AZ80 magnesium alloy has the peak flow stresses of pre-strained alloy with finer grain,which are lower by 20%than those of as-cast alloy under the same deformation conditions.The forming load is related to contact area and average positive stress on interface during forging process.

基于ProCAST的水泵零件精密压铸模具设计

以ProCAST、Pro/E等软件为平台,针对水泵零件的结构特点,模拟金属液的充型凝固过程,分析可能产生的缺陷,优化了浇注系统的设计,从而辅助设计人员进行模具结构的优化设计,实现了水泵零件的精密压铸生产。

基于ProCAST的TiAl合金叶片精铸数值模拟

对TiAl合金叶片的精密铸造过程进行了数值模拟与分析,其中包括充型过程、凝固过程以及模壳温度对凝固的影响。试验结果表明,叶片铸件的缩孔缩松主要沿靠近厚壁一侧的中心线分布,而且叶尖部位以及靠薄壁中心线处比较严重。此外,ProCAST软件模拟结果与实际浇注结果吻合度较高,因此利用模拟制定的工艺方案能够有效地指导实际生产过程。

3D精密铸造实验虚拟仿真系统的设计与实现

随着“智能制造”国家战略的推进,传统铸造工艺亟需向数字化、智能化转型升级。为应对这一需求,利用Unity引擎开发一套3D精密铸造实验虚拟仿真系统。通过构建实验设备的高精度三维模型,还原3D精密铸造工艺的整个流程,实现蜡模制作、石膏型灌浆、焙烧脱蜡和熔炼浇注等关键工艺步骤的模拟。系统丰富的交互式操作和沉浸式体验,为学生提供一个安全、高效、灵活的学习环境。系统已在多门课程得到应用,有效解决精密铸造实验成本高、风险大和设备资源有限等问题,显著提升实验教学效果。

CAST soft CAD／CAE软件在精密铸造生产中的应用

采用CAStsoftCAD模块进行阀体铸钢件精密铸造工艺设计，确定铸件的浇注位置，并计算其浇注系统；通过CAStsoftCAE模块对铸件凝固过程温度场和可能产生的缺陷进行分析，合理优化铸造工艺。实际生产结果表明，CASTsoft软件的模拟结果与实际相符，组合使用CASTsoftCAD／CAE铸造工艺设计和工艺模拟模块可以缩短工艺试制周期，降低工艺试制成本。

基于ProCAST的同步皮带齿轮铸造工艺设计及优化

针对同步皮带轮进行精密铸造工艺设计、仿真及优化,使用ProCAST软件分别对初始的3种浇注方案的充型过程、凝固过程进行模拟,分析充型过程的模拟结果、缺陷分布,确定最佳浇注方案。结果表明,优化浇注方案的最大缩松率为3.70%,缩松、缩孔的总体积低至0.59 cm^(2),保证了产品质量。

涡喷压气机叶片精密铸造工艺探究

叶片精密铸造是熔模精密铸造技术在叶片制造中的应用。本文对涡喷压气机叶片精密铸造工艺进行研究,利用SolidWorks软件建立三维模型,对压气机叶片进行充型凝固数值模拟,并总结出一套合适的铸造工艺。

精密铸铝件一体化设计及在车身轻量化中的应用

铝合金一体化精密铸造技术是实现汽车轻量化的重要方式之一。本文首先采用轻质铝合金材料、熔模真空吸铸工艺以及拓扑优化对白车身前副车架及仪表板横梁进行“材料-工艺-结构”一体化设计;其次对比一体化铝合金结构件的质量、研发成本、研制周期,较原钢制件大幅度降低;最后对加装一体化精密铸铝件的白车身进行刚度与模态的有限元仿真分析及台架试验。结果表明,一体化设计后,前副车架及仪表板横梁分别轻量36.6%、30.8%,同时白车身性能均满足设计要求。

基于石膏型精密铸造实践课程创新探索

以本科生实践课程为基础,将手工陶(油)泥捏塑和先进的逆向扫描技术、3D石膏型精密铸造相结合进行产品开发。首先论述了课程改革的必要性,其次论述了三种方法融合的课程改革及教学方案实施,最后进行了归纳总结,说明平台建设的过程在实践课程中的重要性及意义。

矿物铸件精密电火花线切割机床应用及特性

针对铸件在往复走丝电火花线切割机床制造过程中能耗高、污染大、周期长、内部残余应力大、易变形及使用工作液后绝缘性下降等问题,研制了一种矿物铸件精密电火花线切割机床,该机床达到了团体标准TCMTBA 1010—2021的一系列检测要求。选择经过正常运行使用一年后的矿物铸件和铸铁件机床,分别进行了厚度100 mm工件的8 A大电流和厚度40 mm工件的窄脉冲宽度切割试验发现在相同加工参数条件下,矿物铸件机床在大电流切割时能量泄漏少,运丝速度更平稳,切割效率高于铸铁机床;窄脉冲宽度修刀切割时,铸铁机床在1μs脉冲宽度修刀时极间波形会发生畸变,修刀不稳定,而矿物铸件机床在0.5μs脉冲宽度时还能正常修刀,矿物铸件机床因具有很好的绝缘性,在大能量输出及窄脉冲宽度输出方面具有明显优势。

大型复杂钛合金薄壁件精铸成型技术

钛合金因其高比强度和优良的耐腐蚀性,在航空航天等领域得到了广泛应用。阐述了大型复杂钛合金薄壁件的重要性,介绍了精铸成型技术的原理及在实际应用中存在的问题,对熔模铸造工艺流程、技术特点、精度与复杂度的平衡、材料性能与工艺控制、缺陷控制与质量保证等方面进行了深入分析,为进一步研究提供参考。

铝合金汽车转向节精密铸造工艺研究

目的对某铝合金汽车转向节的精密铸造工艺进行设计与优化研究,以得到合格的铝合金汽车转向节的精密铸造工艺方案。方法结合铝合金转向节铸件的结构特征、铸件材料特性和铸造经验,在转向节铸件主体部和鹅颈部各开设一个内浇口,设计了铝合金转向节初始浇注方案;通过在初始工艺方案中铸件缺陷较严重的区域设置补缩冒口、在铸件顶部增设排气道等措施给出了铝合金汽车转向节的优化浇注方案,基于ProCAST软件建立了铝合金转向节精密铸造2种浇注方案的有限元模型,对铝合金转向节精密铸造的充型过程、凝固过程及缩孔缩松特性进行了数值模拟与分析。结果铝合金转向节铸件初始浇注方案的充型过程相对稳定流畅,铸件在凝固过程中有孤立液相区的形成,完全凝固后铸件中间部位存在大面积缩松缩孔缺陷;优化浇注方案能够控制金属液的流动、充型顺序及凝固特性,铸件的整个凝固过程基本呈中间对称分布,最后凝固区域位于补缩冒口内部,最大缩孔缩松率控制在2%以下。结论优化浇注方案的设计合理且有效,能够有效地消除铝合金转向节铸件的缺陷。

K418高温合金增压器涡轮精密铸造工艺数值模拟研究

该文采用MAGMA铸造仿真软件模拟了K418高温合金增压器涡轮精密铸造工艺,研究了合金液在浇铸过程中的流体温度场、凝固过程中的液相温度场等,然后结合模拟结果试制了增压器涡轮,并对其进行了金相组织分析。结果表明:采用底浇式浇铸系统并将浇注温度设定为1550℃,可以保证合金液具备良好的充型能力;铸件的凝固顺序为:叶片边缘-叶片-叶片轴心-浇冒口-冒口中心,可以保证涡轮零件实现良好成型,并且缩松等缺陷可能出现的位置位于冒口区域;涡轮叶片组织致密,无明显缺陷,叶片位置由柱状晶和细小等轴晶组成,根部及轴心部位为排列整齐的等轴晶。所设计的浇注系统和浇铸温度等工艺合理,可作为实际生产的指导方案。

价值工程在大带冠导叶改进方案的应用

大带冠导叶片毛坯采用方钢,材料利用率低,材料费高,加工时金属去除量大,刀具消耗较大,加工成本高。本篇文章应用价值工程的原理,通过对汽轮机关键核心零部件进行成本分析,以大带冠导叶片为降本对象,从毛坯方案、精加工工艺、产品性能检测、经济效益等方面阐述价值工程对于实际生产应用的指导意义。

某钛合金泵体特种砂型铸造工艺分析及优化

泵体是石油化工领域常用的零部件,在其铸造生产过程中,泵体的底部法兰有蜗型双流道一侧的位置和法兰盘带有凸起的位置存在大的缩孔,热压后出现大压坑,严重影响铸件质量。本文基于Procast软件建立泵体铸造成形仿真模型,分析泵体在不同的铸造方案下的缺陷位置和大小,优化了浇注系统。模拟研究表明,在泵体下法兰设置石墨冷铁进行激冷,有效解决了下法兰大缩孔的问题,缩孔大小由55 cm^(3)减小到1.44 cm^(3),整体减小了97.4%。结合建立的有限元模型,采用正交试验和响应曲面对工艺参数进行优化,模型预测的最佳工艺条件为:初始浇注温度为1770℃,初始浇注半径为37.7 mm,浇注时间为5.1 s,此时泵体的缩孔总大小为1.421 cm^(3)。建模计算与响应曲面模型预测值对比,误差为0.63%,验证了响应曲面模型的可靠性,可为后续实际生产提供指导。