空心叶片LMC定向凝固温度场和微观组织模拟  

Numerical Simulation of Temperature Field and Microstructure during Directional Solidification Hollow Blades by LMC

作　　者：唐宁[1] 张航[1] 许庆彦[1] 柳百成[1] 

机构地区：[1]清华大学材料学院先进成形制造教育部重点实验室

出　　处：《特种铸造及有色合金》2014年第6期561-565,共5页Special Casting & Nonferrous Alloys

基　　金：国家重点基础研究发展计划(973计划)资助项目(2011CB706801);科技重大专项资助项目(2009ZX04006-041;2011ZX04014-052)

摘　　要：基于自主开发的Teccast软件建立了LMC动态综合边界条件和微观组织演变模型,对不同工艺的叶片凝固过程进行了数值模拟。结果表明,与传统方法相比,LMC可得到更窄的糊状区,尤其在厚大部位防止了糊状区的宽化。同时,由于LMC具有更高的温度梯度,并且减小了糊状区下凹的趋势,从而能在更高的拉速下避免杂晶。对于空心单晶叶片,可以在热应力允许的范围内使用更高的拉速来提高生产率。The dynamically changing and combining boundary condition in LMC and the microstructure evolution were simulated by a self-developed software Teccast.Macro-micro structure simulation of blade was conducted at different directional solidification process.The results reveal that the narrower mushy zone can be obtained by LMC compared to the mushy zone in HRS,especially in the thick position.Because of larger temperature gradient and less concave mushy zone by LMC,stray grain can be avoided at higher withdrawal rate.To improve the product efficiency of the hollow SX blade,higher withdrawal rate can be adopted within the range limited by thermal stress.

关 键 词：空心单晶叶片 液态金属冷却 定向凝固 微观组织 数值模拟 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]