Jing YU
材料科学技术（英文）
Bridgman directional solidification of investment castings is a key technology for the production of reliable and highly efficient gas turbine blades. In this paper, a mathematical model for three-dimensional (3D) simulation of solidification process of single crystal investment castings was developed based on basic heat transfer equations. Complex heat radiation among the multiple blade castings and the furnace wall was considered in the model. Temperature distribution and temperature gradient in superalloy investment castings of single blade and multiple ones were investigated, respectively. The calculated cooling curves were compared with the experimental results and agreed well with the latter. It is indicated that the unsymmetrical temperature distribution and curved liquid-solid interface caused by the circle distribution of multiple turbine blades are probably main reasons why the stray grain and other casting defects occur in the turbine blade.
关键词:
Directional solidification
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null
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null
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null
Jing YU
,
Qingyan XU
,
Baicheng LIU
,
Jiarong LI
,
Hailong YUAN
,
Haipeng JIN
材料科学技术（英文）
The directional solidification process of turbine blade sample castings was investigated in the work. Variable withdrawal rates were used in one withdrawal process and compared with the other using uniform rate. A mathematical model for heat radiation transfer and microstructure simulation of directional solidification process was developed based on CA-FD method. The temperature distribution and microstructure were simulated and compared with the experimental results. The stray grains were predicted and compared with the experimental results. The uneven temperature distribution of platform was the main reason of the formation of stray grains.
关键词:
Turbine blade casting
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null
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null
中国腐蚀与防护学报
N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat（6）Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac（13）SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch＆tllsth Of ThlollY68 Oil ITOll ID H....
关键词:
王浩
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刘国权
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秦湘阁
金属学报
采用Potts模型Monte Carlo方法对3种现存的三维个体晶粒长大速率拓扑依赖性
方程进行了仿真验证. 结果表明, Rivier速率方程认为晶粒
体积变化率dVf/dt与晶粒面数f成线性关系, 与仿真
结果明显不符, 不适用于描述三维晶粒长大过程的动力
学. 当晶粒面数f≥8时, Yu-Liu速率方程和
MacPherson-Srolovitz速率方程均与仿真结果很好吻合,
表明这两者均可以用来定量描述三维晶粒长大过程的动力学；当
f＜8时, 这两个方程均与仿真结果有显著差异.
关键词:
三维晶粒长大
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topology-dependent grain growth rate equation
王浩
,
刘国权
,
秦湘阁
金属学报
doi:10.3321/j.issn:0412-1961.2008.01.003
采用Potts模型Monte Carlo方法对3种现存的三维个体晶粒长大速率拓扑依赖性方程进行了仿真验证.结果表明,Rivier速率方程认为晶粒体积变化率dVf/dt与晶粒面数,成线性关系,与仿真结果明显不符,不适用于描述三维晶粒长大过程的动力学.当晶粒面数f≥8时,Yu-Liu速率方程和MacPherson-Srolovitz速率方程均与仿真结果很好吻合,表明这两者均可以用来定量描述三维晶粒长大过程的动力学;当f<8时,这两个方程均与仿真结果有显著差异.
关键词:
三维晶粒长大,拓扑依赖性长大速率方程,Potts模型,Monte Carlo仿真
李文琳
,
李章炜
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幸七四
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张扬
贵金属
膜片开关用银浆制备使用的有机体系中，树脂、溶剂和添加剂对产品的性能和有害元素控制有重要的意义。经对比实悚，以热塑性聚酯为主体树脂，以MEA混合溶剂为溶剂，以YU-201、硅烷偶联剂以及自制增强塑性材料M-17材料为混合添加剂，制成有机载体。使用该载体制备出的浆料符合膜片开关银浆性能要求，且满足欧盟RoHS指标卤素控制要求。
关键词:
复合材料
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环保型
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无卤素
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膜片开关
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银浆
吕友军
,
董旭斌
,
张天宁
工程热物理学报
本文采用基于颗粒动力学的欧拉双流体模型,对比研究了曳力和湍流对超临界水流化床传热特性的影响,选取了Gidaspow、Syamlal-O'Brien和Wen-Yu三种曳力模型以及标准κ-ε、RNG κ-ε、Realizable κ-ε湍流模型三种高Re数湍流模型及低Re数κ-ε湍流模型.研究结果表明,在三种曳力模型中,Gidaspow曳力模型在超临界水流化床中更为适用;对于所采用的四种κ-ε湍流模型,利用三种高雷诺数湍流模型模拟所得床层与壁面间传热系数基本一致且大于采用低雷诺数模型模拟所得传热系数,而综合考虑,RNGκ-s湍流模型更适于超临水流化床传热特性的研究.
关键词:
超临界水流化床
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曳力
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湍流
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传热
