基于熔融沉积技术的燃机叶片快速熔模铸造工艺优化研究

针对熔融沉积技术应用于熔模铸造燃机叶片时存在的因材料熔融膨胀流动而导致型壳胀裂、表面品质和尺寸精度难以保证等问题,分别进行了3D打印ABS材质的实心、空心叶片模样用于熔模铸造的实验,研究了熔模铸造过程中的蜡质浇注系统设计、涂挂工艺参数、脱蜡和脱ABS材料工艺流程优化技术。通过对铸件尺寸精度的检测表明,ABS材质空心叶片模样的铸件产品尺寸精度优于实心叶片产品。     

基于熔融沉积技术的叶片快速熔模铸造试验

针对燃气轮机叶片熔模铸造过程复杂、周期长、成本高等问题,利用3D打印熔融沉积技术打印ABS模型,粘接蜡模浇注系统组成模组,经过涂挂涂料、高压釜脱ABS和焙烧获得完整的叶片型壳,并采用工业内窥镜对其型腔内部进行检测后浇注金属液。采用三维光学扫描方式对铸件的整体尺寸和其叶型截面的关键尺寸偏差值进行检测。试验表明,采用熔融沉积技术打印叶片模型进行快速熔模铸造能够满足铸造要求,为燃气轮机叶片样件熔模铸造提供一种时间短、成本低、可靠性高的新方法。     

光固化成型的燃机叶片快速熔模铸造研究

针对某型燃机叶片快速成型进行性能实验研究的需要,提出一种基于光固化成型技术的树脂叶片模型作为熔模进行熔模铸造叶片的工艺方法。通过研究模型材料的加温试验,探究型壳中的空气对型壳的影响试验,研究型壳厚度对型壳内应力的影响规律,对叶片铸造工艺中出现的型壳开裂问题进行分析研究。研究结果表明:型壳产生破裂主要由于型壳强度不足,以及型壳厚度、材料受热膨胀等因素的影响。     

重型燃机叶片熔模铸造过程的数值模拟

采用Procast软件模拟计算重型燃机叶片熔模铸造过程的温度场,对凝固过程进行了分析,研究了不同的浇注温度对叶片缩松的影响.结果表明,随着浇注温度提高,叶根、叶身处缩松均减少.通过在型壳适当的位置加冷铁、包裹保温棉,可以显著地减少叶片的缩松.对模拟得到的较优工艺进行试验验证,叶片缩松的位置、变化规律与模拟结果相吻合.     

熔融沉积式燃机叶片快速熔模铸造技术研究与试验（英文）

针对某燃机叶片叶型部分形状复杂和轮廓度精度要求高的特点,提出了一种基于熔融沉积技术的燃机叶片快速熔模铸造方法,通过基于NURBS曲线的分层截面生成算法对燃机叶片STL(stereolithography)模型进行分层,提高燃机叶片模样的轮廓度精度,制订了燃机叶片快速熔模铸造工艺流程,采用三坐标测量机对燃机叶片铸件进行测量,对其两个关键截面进行型线轮廓度偏差分析与评价,结果表明:基于熔融沉积技术的快速熔模铸造燃机叶片铸件在轮廓精度方面满足要求,快速熔模铸造工艺流程合理、可行。     

基于增材制造的叶轮熔模铸造的工艺研究

以叶轮铸件为研究对象，设计了顶注式、侧注式和底注式3种浇注系统。借助AnyCasting软件，分析优选出最佳浇注系统。结合增材制造3D打印制作叶轮熔模，并采用熔模铸造工艺生产出了合格的叶轮铸件。结果表明，侧注式浇注系统充型过程平稳，卷气、缩松、缩孔较少，3D打印在熔模铸造中的应用，有效缩短零件开发周期，降低成本，大大提高了生产效率。     

基于TRIZ矛盾矩阵的快速熔模铸造工艺开发与实践

为提高生产率,增加可靠性,基于TRIZ矛盾矩阵的原理,提出解决压型定型周期长问题的措施,提出了快速熔模铸造工艺路线。采用增材制造技术打印得到ABS材质铸件模样,采用常规方法制作蜡质浇注系统,试验粘接工艺和调整涂料配方,组成蜡模组,多层挂砂得到型壳,分别脱蜡、脱ABS,经过浇注、清理,获得了合格铸件。     

光固化增材制造技术在熔模铸造中的应用

增材制造工艺可以实现复杂形状直接成形,其中光固化增材制造技术具有成形精度高的优势.利用光固化增材制造技术制备熔模,然后与熔模铸造工艺相结合,可以更好地发挥两种工艺的优势,缩短工艺周期.利用光固化增材制造技术制备熔模铸造用陶瓷型芯、型壳,可实现熔模铸造工艺的快速响应.文中简介了光固化增材制造技术的相关设备及成形原理,并分...     

基于熔融沉积技术的快速熔模铸造工艺实践

确定新产品的熔模铸造工艺需要反复试验验证,设计周期长,成本高。利用熔融沉积技术(FDM)打印ABS模样,采用常规方法用蜡制造浇冒系统模样,二者黏接组成模组。涂挂试验配方的涂料实现挂砂,通过高压釜脱蜡和焙烧炉脱ABS两步过程,获得完整的型壳。焙烧、浇注、冷却后,进行喷砂清理,采用三维扫描仪检测产品尺寸。实现了基于熔融沉积技术(FDM)的快速熔模铸造生产铸钢件。     

快速成型及快速熔模铸造技术

介绍了快速成型及快速熔模铸造技术。分析了熔模铸造（IC）和快速成型（RP）的主要制造方法,国外研究结果证明,熔模铸造（IC）作为一种大批量生产具有高几何复杂度和高精度近净形金属零件的经济方式,已使众多行业受益。熔模铸造的经济效益局限于大批量生产。与蜡模成型硬质模具的发展相比,高成本和制造周期长显现出熔模铸造在小批量生产中是不经济的。快速成型零件可以代替常规熔模铸造的蜡模或充当蜡注塑成型生产模具,它杰出的制造能力为小批量熔模铸造提供了具有成本效益的解决方案。     

基于知识模板的涡轮叶片精铸模设计方法研究

提出了基于知识模板的涡轮叶片精铸模设计方法,介绍了知识模板的定义、构建方法及基于知识模板的设计方法等关键技术。面向装配过程,设计了具有参数化关联的模具模板结构,实现基于模板知识的精铸模自动生成,缩短了精铸模设计周期,提高了精铸模标准化程度和设计知识利用率。     

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.     

精铸涡轮叶片蜡模模具型面优化设计方法

提出一种基于有限元法的精铸涡轮叶片蜡模模具型腔优化设计方法。首先,计算出涡轮叶片在凝固和冷却过程中的非均匀、非线性收缩变形量;然后,基于本文提出的位移场反向迭代算法,确定优化的蜡模模具型腔。以A356合金涡轮叶片为例,采用提出的涡轮叶片模具型腔优化设计系统,经过精度评估,尺寸误差得到了大幅度降低。数值模拟与实验结果吻合良好,经过4次迭代优化,涡轮叶片的总体形状误差从0.515815mm降低至0.001978mm。     

Geometric analysis of investment casting turbine blades based on digital measurement data简

A turbine blade is one of the key components of the aero-engine.Its geometric shape should be inspected carefully in the production stage to ensure that it meets the tolerance specification.In the present paper,an approach for investment turbine blade geometric shape analysis based on multi-source digital measurement is presented.Its key technologies,such as measurement data collection,blade model reliable alignment,geometric shape deviation fast calculation and visualization,were investigated.Actual measurement data from a structure light measurement device and a Coordinate Measuring Machine （CMM） for turbine blades were used to validate the presented method.The experimental results show that the proposed method is accurate,quick and effective to implement.     

Intelligent design of investment casting mold based on a hybrid reasoning method

A hybrid reasoning model was proposed in which CBR (case-based reasoning) was applied to the conceptual design and RBR (rule-based reasoning) was applied to the detailed design after research of the design process and domain knowledge of the acre-engine turbine blade investment casting mold design field. In the conceptual design stage, the representation and retrieval technologies were researched which improve the retrieval efficiency. Meanwhile, RBR was used to modify the retrieval result. The experimentation shows that the approach in this study can be used to obtain a more satisfactory design result.     

Multiscale modelling and simulation of single crystal superalloy turbine blade casting during directional solidification process

As the key parts of an aero-engine,single crystal（SX）superalloy turbine blades have been the focus of much attention.However,casting defects often occur during the manufacturing process of the SX turbine blades.Modeling and simulation technology can help to optimize the manufacturing process of SX blades.Multiscale coupled models were proposed and used to simulate the physical phenomena occurring during the directional solidification（DS）process.Coupled with heat transfer（macroscale）and grain growth（meso-scale）,3D dendritic grain growth was calculated to show the competitive grain growth at micro-scale.SX grain selection behavior was studied by the simulation and experiments.The results show that the geometrical structure and technical parameters had strong influences on the grain selection effectiveness.Based on the coupled models,heat transfer,grain growth and microstructure evolution of a complex hollow SX blade were simulated.Both the simulated and experimental results show that the stray grain occurred at the platform of the SX blade when a constant withdrawal rate was used in manufacturing process.In order to avoid the formation of the stray crystal,the multi-scale coupled models and the withdrawal rate optimized technique were applied to the same SX turbine blade.The modeling results indicated that the optimized variable withdrawal rate can achieve SX blade castings with no stray grains,which was also proved by the experiments.     

Processing and microstructure of investment casting turbine blade NITAC in-situ composites

Directional solidification was used to produce turbine blades by the Bridgman method. NITAC alloys with various carbon contents were investigated; the optimum range was found to be 0.40 to 0.48%. Within this range, except for the blade locking piece edges, the blade structure consisted predominantly of aligned eutectics. The in- situ eutectics were aligned tantalum fibers embedded in a γ- phase matrix. The blades were produced using an alloy displacement rate of 1.86 x 10 ^{- 6} m/s. Measurements of fiber spacings along the blade height indicated that the rate of displacement of the solidification front exhibited some variations. These variations were closely associated with dimensional changes in the turbine blade cross sections.     

基于RSM和GA的涡轮熔模铸造工艺优化

以涡轮熔模铸件浇注系统设计为例,基于BOX-BehnKen设计响应面试验(RSM)建立了二阶响应面模型,探究了浇注系统半径、高度与浇注温度对铸件内部缺陷的体积和缺陷与铸件表面之间的距离的影响,并利用遗传算法(GA)优化工艺参数。数值模拟分析结果表明,该优化方案可以在得到无缺陷涡轮铸件的同时达到80.53%的工艺出品率,为熔模铸造浇注系统的设计优化提供思路。     

某汽轮机叶片材料热变形行为及锻坯参数优化

为提高某叶片锻件质量和生产效率、减少模具磨损,采用热模拟试验研究了叶片材料的热变形行为,建立了材料的高温流动应力方程;以此方程作为材料模型,对叶片的锻造过程进行了数值模拟,优化了制坯工艺参数.试验分析表明,该材料热变形行为符合双曲正弦函数关系;数值模拟结果表明,采用叶根与叶冠成40°角的坯料较优,成形质量与成形载荷对坯...     

A real-time measuring technology for studying distortion of hydraulic turbine blade castings during heat treatment process

During heat treatment process, the distortion behavior inevitably appears in hydraulic turbine blade castings. In this research, a technology was developed for real-time measurement of the distortion in hydraulic turbine blade castings at the still air cooling and forced air cooling stages during heat treatment process. The method was used to measure the distortion behavior at the cooling stages in both normalizing and tempering processes. At the normalization, the distortion at the blade corner near outlet side undergoes four stages with alternating bending along positive and negative directions. At the tempering stage, the distortion could be divided into two steps. The temperature difference between the two surfaces of blade casting was employed to analyze the distortion mechanism. The measured results could be applied to guide the production, and the machining allowance could be reduced by controlling the distortion behavior.