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《电加工与模具》2015,(6)
在空心涡轮叶片型芯型壳一体化陶瓷铸型制备过程中,对光固化叶片原型进行整体式内腔结构设计,可显著降低原型烧失过程中铸型的热应力,避免型壳开裂。但在大尺寸叶片铸型的凝胶注模成形过程中,叶片原型榫根部位因刚度偏低,在陶瓷浆料静压力作用下会变形,导致铸型精度较差。为此,提出了一种原型分区域内腔结构设计方法,并基于叶片原型静压力结构刚度-铸型热结构强度有限元模拟,确定了叶身和榫根部位分别采用0.7 mm和0.9 mm的内腔结构尺寸。采用工业CT及逆向精度分析比较了分区域内腔结构设计前后铸型的精度变化,结果表明:分区域内腔结构设计方法降低了凝胶注模过程中原型榫根部分的静压力变形,有效改善了铸型的整体精度,避免了脱脂过程中铸型开裂,可制备出精度高、结构完整的大尺寸叶片陶瓷铸型。 相似文献
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对K465合金等轴晶铸造涡轮叶片进行了热等静压,研究了热等静压工艺对铸造涡轮叶片的显微疏松、组织、性能及极限疲劳试验的影响。通过与熔模铸造涡轮叶片对比,验证了热等静压对涡轮叶片显微疏松和疲劳强度的作用效果。结果表明:采用热等静压能够显著减少K465等轴晶铸造涡轮叶片的显微疏松及孔洞类缺陷,并能提高叶片的室温拉伸强度、高温持久强度和极限疲劳强度等性能。 相似文献
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应财德 《特种铸造及有色合金》1994,(3):24-26
四级涡轮转子叶片是某型号燃汽轮机高压转子部件动力涡轮中零件尺寸最大、外形结构复杂、叶片各项性能要求极高(如叶片弯扭度、型面尺寸精度、表面粗糙度及铸件内部冶金质量等)的熔模精密铸件。其材料为国际镍公司研制的新型IN738高温镍基合金,化学成分复杂,力学性能要求高,所以精铸工艺难度大。通过四级涡轮转子叶片的试制,对大型叶片熔模精铸生产过程中的变形和疏松两大工艺难点及采取的工艺措施作了介绍。 相似文献
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针对航空发动机单晶空心涡轮叶片的精确控形技术,结合国内外相关工作的研究状况,从空心涡轮叶片复杂陶瓷型芯精密成形技术、单晶高温合金叶片近净形熔模精密铸造技术及叶片精铸过程尺寸精度控制方法等方面,对单晶空心涡轮叶片精确控形技术领域取得的研究成果进行了总结和分析。重点介绍单晶空心涡轮叶片精确控形技术领域内取得的研究成果,论述了我国单晶空心涡轮叶片精确控形技术的未来研究重点。 相似文献
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航空发动机上涡轮的零件由难于机械加工的耐热合金制成,零件的尺寸要求精确且形状复杂,例如图1所示为涡轮转子叶片。要制造内腔带有冷却孔道的,形状复杂的叶片零件,通常采用无余量熔模精密铸造的方法。一、对无余量精铸件的精度要求无余量精密铸造并非不留一点加工余量,只是将余量控制在允许范围内,表1列举了斯贝发动机的几个典型精铸件的尺寸公差。二、无余量精铸工艺精铸件主要工作表面由加工到不加工,必 相似文献
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复杂结构空心高压涡轮导向叶片精密铸造工艺 总被引:2,自引:0,他引:2
对双联复杂结构空心高压涡轮叶片的精密铸造工艺进行了研究。结果表明,采用硅基陶瓷型芯为主芯并组合石英管,使制备空心叶片铸造用陶瓷型芯工艺过程明显简单化,提高了陶瓷型芯的成品率。采用该型芯成功制备了合格的双联空心高压涡轮叶片。 相似文献
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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。 相似文献
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Baicheng Liu Qingyan Xu Tao Jing Houfa Shen Zhiqiang Han 《JOM Journal of the Minerals, Metals and Materials Society》2011,63(4):19-25
The development of the aviation, energy and automobile industries requires an advanced integrated product/process R&D systems
which could optimize the product and the process design as well. Integrated computational materials engineering (ICME) is
a promising approach to fulfill this requirement and make the product and process development efficient, economic, and environmentally
friendly. Advances in multi-scale modeling of solidification and casting processes, including mathematical models as well
as engineering applications are presented in the paper. Dendrite morphology of magnesium and aluminum alloy of solidification
process by using phase field and cellular automaton methods, mathematical models of segregation of large steel ingot, and
microstructure models of unidirectionally solidified turbine blade casting are studied and discussed. In addition, some engineering
case studies, including microstructure simulation of aluminum casting for automobile industry, segregation of large steel
ingot for energy industry, and microstructure simulation of unidirectionally solidified turbine blade castings for aviation
industry are discussed. 相似文献
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Tian Jia-wei Bu Kun Song Jin-hui Tian Guo-liang Qiu Fei Zhao Dan-qing Jin Zong-li Li Yang 《中国铸造》2017,14(6):469-477
The large warping deformation at platform of turbine blade directly affects the forming precision. In the present research, equivalent warping deformation was firstly presented to describe the extent of deformation at platform. To optimize the process parameters during investment casting to minimize the warping deformation of the platform, based on simulation with Pro CAST, the single factor method, orthogonal test, neural network and genetic algorithm were subsequently used to analyze the influence of pouring temperature, shell mold preheating temperature, furnace temperature and withdrawal velocity on dimensional accuracy of the platform of superalloyDD6 turbine blade. The accuracy of investment casting simulation was verified by measurement of platform at blade casting. The simulation results with the optimal process parameters illustrate that the equivalent warping deformation was dramatically reduced by 21.8% from 0.232295 mm to 0.181698 mm. 相似文献
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Dong Pan Qingyan Xu Baicheng Liu Jiarong Li Hailong Yuan Haipeng Jin 《JOM Journal of the Minerals, Metals and Materials Society》2010,62(5):30-34
Single crystal superalloy turbine blades are currently widely used as key components in gas turbine engines. The single crystal
turbine blade casting’s properties are quite sensitive to the grain orientation determined directly by the grain selector
geometry of the casting, A mathematical model was proposed for the grain selection during directional solidification of turbine
blade casting. Based on heat transfer modeling of the directional withdrawing process, the competitive grain growth within
the starter block and the spiral of the grain selector were simulated by using the cellular automaton method (CA). Validation
experiments were carried out, and the measured results were compared quantitatively with the predicted results. The model
could be used to predict the grain morphology and the competitive grain evolution during solidification, together with the
distribution of grain orientation of primary <001> dendrite growth direction, with respect to the longitudinal axis of the
turbine blade casting. 相似文献
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