铝合金熔模精密铸造界面换热系数测量  

Determination of Interfacial Heat Transfer Coefficient During the Investment Casting of Aluminum Alloy

作　　者：邵珩[1] 罗志辉[1] 李岩[2] 赵亚利[2] 南海[2] 许庆彦[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,北京100084 [2]北京航空材料研究院,北京100095

出　　处：《铸造》2014年第10期1010-1013,1018,共5页Foundry

基　　金：中欧航空国际合作项目;欧盟第七框架项目;973计划(2011CB706801);国家自然科学基金(51171089;51374137);国家重大科技计划(2012ZX04012011);863计划(2007AA04Z141)

摘　　要：熔模精密铸造对于铸件近净成形具有重要意义,但目前鲜见对其铸件-铸型界面换热系数的相关研究。本试验在一维传热模型中采用非线性估算法对工业纯铝在熔模铸造过程中与型壳的换热行为进行了研究,分析结果表明:在凝固前期,铸件与型壳之间的热流密度基本不变,而界面换热系数随两者温差减小而增大;凝固中期,界面换热系数随着整体固相分数增加而线性下降;凝固后期,界面换热系数下降变得十分缓慢。将在一维模型中反求得到的界面换热系数应用到三维铸件模型中,得到的模拟温度与实测温度基本吻合,证明通过一维模型与非线性估算法求取的界面换热系数比较准确,有望在铝合金精密铸造温度模拟中得到应用。Investment casting is a very important near net shape process for casting, while the research for the interfacial heat transfer coefficient （IHTC） between casting and shell during investment casting is very rare. The IHTC between aluminum casting and shell in investment casting was determined on the basis of the experimental data and a 1-D model with the nonlinear estimation method. The results indicate that the interfacial heat flux remains largely unchanged while the IHTC increases with the decreasing temperature difference between casting and shell during the first stage of solidification. Then the IHTC decreases linearly as the solid fraction increases in the second stage. Afterwards the 1HTC drops very slowly. The relationship between the IHTC and the condition of the casting based on the 1-D model was applied to the temperature calculation of the actual 3-D model of casting and shell and the calculated temperature data were close to the experimental data, the interfacial heat transfer coefficient which was obtained by a 1-D model and the nonlinear estimation method is correct, thus the relationship may be applied to the temperature simulation in investment casting of aluminum.

关 键 词：熔模铸造 界面换热系数 非线性估算法 铝合金 

分 类 号：TG292[金属学及工艺—铸造]