Thermal Analysis of the Bridgman and Liquid-Metal-Cooled Directional Solidification Investment Casting Processes
Thermal Analysis of the Bridgman and Liquid-Metal-Cooled Directional Solidification Investment Casting Processes
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DOI：
10.1007/s11661-006-9085-2
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发表时间：
2007-04
期刊：
影响因子：
--
通讯作者：
A. Elliott;T. Pollock
中科院分区：
文献类型：
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作者：
A. Elliott;T. Pollock
在定向凝固过程中获得的镍基高温合金铸件的布里奇曼和液态金属冷却（LMC）技术的热分布已被用来开发和验证这些过程的有限元模型。圆柱晶粒合金GTD-444的定向凝固过程的模型被用来评估在每个过程中的各种传热步骤和热提取模式。这种分析突出了两种凝固方法之间的传热模式的相似性和根本差异。最终，确定每个过程的唯一限制传热步骤。对于阶梯板配置调查，热提取是有限的辐射从模具外表面在布里奇曼过程。铸件和内部模具表面之间的热传递是LMC工艺中的主要阻力，并且在该工艺中通过降低冷却剂温度来增强热提取。
Thermal profiles obtained during directional solidification of Ni-base superalloy castings by the Bridgman and liquid-metal-cooled (LMC) techniques have been used to develop and validate the finite-element models of these processes. Models of the directional solidification processes for the columnar-grain alloy GTD-444 are used to evaluate the various heat-transfer steps and heat extraction modes within each process. This analysis highlights the similarities and the fundamental differences in heat-transfer modes between the two solidification approaches. Ultimately, the unique limiting heat-transfer step of each process is identified. For the stepped plate configuration investigated, heat extraction is limited by radiation from the exterior mold surface in the Bridgman process. Heat transfer between the casting and the interior mold surface is the primary resistance in the LMC process, and heat extraction is enhanced by the lowering coolant temperatures in this process.