铝铸件凝固过程微观组织模拟的研究
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摘要
随着我国工业水平的提高，铝合金铸件以其优异的性能获得越来越广泛的应用。采用计算机数值模拟技术预测铝合金铸件的微观组织的形核和生长以及溶质的扩散过程，并最终能预测铸件的机械性能，是当今国内外该领域的研究热点。
作者以金属凝固理论为基础，确定论方法和随机论方法相结合，建立了二维基础上模拟铝合金铸件微观组织的数学物理模型。该模型中包括了晶体的形核模型和生长动力学模型。在晶体生长过程中，考虑了枝晶的优先生长方向和柱状晶向等轴晶转变(CET)等问题。并将目前较为成熟的温度场模型引入到微观组织模拟中。利用温度梯度加速度与抗拉强度之间的关系，计算出模拟区域的抗拉强度，进而换算为硬度，达到预测铝合金铸件机械性能的目的。
作者以Microsoft公司的Visual C++6.0作为软件的开发工具，利用微机开发了在Windows 2000环境下运行的具有自主权的模拟系统。该系统能够较好的模拟铝合金铸件的微观组织和预测铸件的机械性能。
作者选择了”T”型铝合金铸件进行了实验研究。分别改变了铸件的合金成分、铸型材料和不同的浇注温度进行了实际的实验验证。对在不同条件下得到的铸件，观察其微观组织，同时对硬度进行测量。结果表明，计算机的数值模拟与实验的结果比较接近，说明了软件能够较好的模拟铝合金铸件的微观组织，达到预测铸件机械性能的目的。
With the development of the China. Aluminium alloy Cast, owing to their excellent properties ,has gotten more and more applications. Recently the numerical simulation of solidification process has been used to predict the nucleation and growth of grains and the diffusion of solute atoms in the microstructure of aluminium alloy casting and to evaluate the mechanical properties of the products, which has become one of the hotest topics for foundry all over the world.
A combined Deterministic method and Probabilitistic method on the basis of the theory of metal solidification have been successfully used to set up a two-dimensional methematics and physical model which includes the nucleation model and the growth kinetic model to simulate the microstructure of almuminium alloy casting. In this model ,the preferred growth dorection of dendritic grains and the change of columnar grain to exquiaxed grain(CET) have been considered and the macroscopic simulation was introduced into microstructure simulation. A unified micro-macro model has been used succesfully to simulation the microstructure of aluminium alloy casting and to caculate the tensile strength of certain zone with the aids of obtained relation of temperature-grade acceleration rate and tensile strength.
Microsoft Visual C++ 6.0 has been used to set up this simulation system that works under Windows 2000. This system can be used to simulation the microstructure and to predict the mechanical properties of the aluminium alloy casting.
The "T" shape aluminium alloy casting were selected to test the simulation model. In a series of experiments, the different alloy compositions of the casting and the different mould materials and the different pour temperature were seleced to produce some different casting, and their microstructure characters were observed and their hardnesses were measured. The experiments indicate that the simulation results were accord with the experiment results, which proved the validity of this software system as a useful tool to predict the microstructure properties of aluminium alloy casting.
作者以金属凝固理论为基础，确定论方法和随机论方法相结合，建立了二维基础上模拟铝合金铸件微观组织的数学物理模型。该模型中包括了晶体的形核模型和生长动力学模型。在晶体生长过程中，考虑了枝晶的优先生长方向和柱状晶向等轴晶转变(CET)等问题。并将目前较为成熟的温度场模型引入到微观组织模拟中。利用温度梯度加速度与抗拉强度之间的关系，计算出模拟区域的抗拉强度，进而换算为硬度，达到预测铝合金铸件机械性能的目的。
作者以Microsoft公司的Visual C++6.0作为软件的开发工具，利用微机开发了在Windows 2000环境下运行的具有自主权的模拟系统。该系统能够较好的模拟铝合金铸件的微观组织和预测铸件的机械性能。
作者选择了”T”型铝合金铸件进行了实验研究。分别改变了铸件的合金成分、铸型材料和不同的浇注温度进行了实际的实验验证。对在不同条件下得到的铸件，观察其微观组织，同时对硬度进行测量。结果表明，计算机的数值模拟与实验的结果比较接近，说明了软件能够较好的模拟铝合金铸件的微观组织，达到预测铸件机械性能的目的。
With the development of the China. Aluminium alloy Cast, owing to their excellent properties ,has gotten more and more applications. Recently the numerical simulation of solidification process has been used to predict the nucleation and growth of grains and the diffusion of solute atoms in the microstructure of aluminium alloy casting and to evaluate the mechanical properties of the products, which has become one of the hotest topics for foundry all over the world.
A combined Deterministic method and Probabilitistic method on the basis of the theory of metal solidification have been successfully used to set up a two-dimensional methematics and physical model which includes the nucleation model and the growth kinetic model to simulate the microstructure of almuminium alloy casting. In this model ,the preferred growth dorection of dendritic grains and the change of columnar grain to exquiaxed grain(CET) have been considered and the macroscopic simulation was introduced into microstructure simulation. A unified micro-macro model has been used succesfully to simulation the microstructure of aluminium alloy casting and to caculate the tensile strength of certain zone with the aids of obtained relation of temperature-grade acceleration rate and tensile strength.
Microsoft Visual C++ 6.0 has been used to set up this simulation system that works under Windows 2000. This system can be used to simulation the microstructure and to predict the mechanical properties of the aluminium alloy casting.
The "T" shape aluminium alloy casting were selected to test the simulation model. In a series of experiments, the different alloy compositions of the casting and the different mould materials and the different pour temperature were seleced to produce some different casting, and their microstructure characters were observed and their hardnesses were measured. The experiments indicate that the simulation results were accord with the experiment results, which proved the validity of this software system as a useful tool to predict the microstructure properties of aluminium alloy casting.
引文
[1] 荆涛．凝固过程数值模拟．清华大学讲义．1994年
[2] J. Forsund. Giesserei. 1962(14).51
[3] 柳百成。铸造工艺CAD凝固过程数值模拟分析研究。内部资料．1992
[4] Pikin J E J.Methoding in a 3D CAD Environgment. Foundry Management&Technology. Nov. 1992. 26～28
[5] Editor.Improving the Benefits of Foundries Through the New MAGMASOFT Release3.3.5. Foundryman. june 1997.206～207
[6] Jolly M.R. Cast Benefits Solidification Simulation to Foundry Trade Journal. Oct .6 1989. 744～750
[7] Kreziak G. Low Pressure Permanent Mould Process Simulation of a thin Wall Aluminum casting Materials Science and Engineering.Dec. 20.1993.255～259
[8] Editor.Simulor Software Achieves 10 Years Maturity.Foundry Trade.j.july 1994.325～326
[9] Esrin.L.A. Deeper Look at Casting Solidification Software. Modern Casting. July 1994 20～24
[10] Cope M A. Metal Flow Design Concept .May 1995
[11] Manual of Procast. UES Corporation. 1996
[12] Nagasaka, Y, Linguchi, S.,Nachi. M. and Brimacombe, J.K.,AFS Trans.,1989(117).554
[13] Marrone R.E. Numerical Simulation of Solidification Part I. Low Carbon Steel Casting-L.Shape. AFS Casting Metals Research Journal. 1970(12).184～192
[14] Hou T X. Computation of Solidification of a Steel Casting Against a Chill Mold Wall. Afs Trans. 1988.151～160
[15] Hansen P N. Solidification and Casting of Metals. Arrow Smith Loct. London. 177.350～361
[16] 姚山。大型铸钢齿轮三维有限差分的计算机自动剖分及凝固数值模拟．铸造．1995(2)．6～11
[17] 郭可仞．大型铸件凝固过程数值模拟．大连工学院学报．1980．19(1)．1～16
[18] Ohnaka I. Calculation of Solidification of Casting by Matrix Method. Trans. Iron Steel Inst. Japa. 1977.410～418
[19] 朱宪华．用直接差分法机械凝固过程数值解析．西安交通大学学报．1983(2)．49～60
[20] 徐东．铸件凝固过程温度场数值模拟及缩孔缩松预测实用软件开发．铸造，1988(2)1～8
[21] 大中逸雄．计算机传热凝固解析入门．机械工业出版社．1988
[22] Brown S G.A Rapid Alternative to Solidification Modelling. Modern Casting. Dec. a993.24～25
[23] Wen S W. Simulation of a Automobile Wheel Casting Process. Proceedings of the 61st World Foundy Congress. Sept. 1995. Bei jing. 524～552
[24] 裴清祥．铸造充型过程三维数值模拟及铸造工艺CAD系统的研究。[博士学位论文]．北京：清华大学．1991．1
[25] 荆涛．三维集成铸造工艺CAD／CAE系统研究．[博士学位论文]．北京：清华大学．1993．5
[26] 高志强．铸造过程流场温度场三维数值模拟．[博士学位论文]．北京：清华大学．1995．5
[27] 常庆明．大型薄壁铸件三维充型几何传热的数值模拟．[博士学位论文]．哈尔滨：哈尔滨工业大学．1985
[28] Chen J H. Comparison on Different Modes of Latent Heat Release for Modeling Csting Solidificatinon. AFS Trans.1990 539～546
[29] 贾宝仟．铸钢件的热裂预测及其数值模拟．[博士学位论文]．北京：清华大学．1996
[30] W.Oldfield, A Quatitative Approach to Casting Solidification. Freezing of Cast Iron, ASM Trans..1966(59).945～961
[31] D.M. Stefanescu, C.S. Kanetkav. AFS Trans..1987(95).139～144
[32] I.Minkoff. the Foundryman. 1993(1、2).16～22
[33] D. Dgoettsch and J.A. Dantzig. Metallurgical and Materials Transactiong. 1994(25A).1063～1079
[34] J. ZouandM. Rappaz. The Minerals, Metals&Materials Society .1991.335～36O
[35] ph. Thevoz, J.L. Desbioles and M. Rappaz. Metall. Trans. 1989(20AO. 311～322
[36] M. Castro, J. Lacaze, N. Aichoun and G. Lescoult. Memoirres et Etudes Scientifiquess Revue de Metallurgie. 1989(2).85～97
[37] M.P. Anderson, D.J. Srolovitz, G. Sgrest, and P.S Sahni. Acta Metall.1984(32).783
[38] J. A. Spittle and S.G. Brown. Acta Metal11989(37).1803
[39] P. Zhu and W. Smith. Acta Metall.1992(40).3369
[40] Ch-A. GANDIA and M. Rappaz..Acta metal mater. 1994. vol. 42.2233～2246
[41] W. kurz, B.Giovanota and R. Trived. Acta Metall.1986(34).823
[42] R. Trivedi, P. Magin and W. Kurz. Acta Metall. 1987(35).971
[43] C. W. Price. Acta Metall. 1987(35).1377
[44] M. Rappaz. Imt Mater. Rev. 1989(34).93
[45] Ph. Thevoz, J-L. Desbiolles, M. Rappaz. Metall.Trans.,20A(1989).311～322
[46] Wang. C. Y, Beckermann. C. Metall. Trans. A, 1993,24A 2787～2802
[47] Wang. C. Y, Beckermann. C. Metall. Trans. A, 1993,26B 111～119
[48] Ph. Thevoz, J-L. Desbiolles, M. Rappaz. Light Metals.,Ed. By Ch.M. Bickkert, TMS 1990,975～984
[49] M.M' Hamdi, Hcombeau, G. Lesoult. Numerical Modeling of the Coloumnar to Equiaxed Transition in Continous Casting of Steel. Modeling of Casting, Welding and Advanced Solidification Processes VIII, Ed. By G. Thomas and C. Beckermann, TMS, Warrendale, Pennsylvania, USA(1998),375～382
[50] M. Rappaz and E. Biank. J. Cryst. Grith. 1986(74).67
[51] W. Oldfield.A Quantitative Approach to Casting Solidification:Freezing of Cast Iron. ASM Trans.,59,1966,945～960
[52] J.-L. Desbiolles, Ch.-A. Gandin, J.-F. Joyeux, M. Rappaz and Ph. Thevoz. A 3DCAFE Model for the Predication of Solidification of Grain Structures. Modeling of Casting, Welding and Advanced Solidification Processes Ⅷ.1998,433～440
[53] Warren J A, Boettinger W J, Prediction of dendritic growth and microsegregztion patterns in a binary alloy using the phase-field method [J]. Physical Review A, 1991,43(100:1310～1317
[54] I.Steinbach, G.J. Schmitz. Three Dimensinal Modeling of Equiaxed Dentritic Growth on a Messoscopic Scale. Acta Mater.,47(1999):971～982
[55] 胡汉起．金属凝固．冶金工业出版社．1985
[56] 侯增寿，卢光熙．金属学原理．上海科学技术出版社．1990
[57] J. Lipton, W. kurz, and R. Trivedi. Acta Metall..1987. Vol. 35.957～964
[58] W. Kurz, B. givonaola and R. Trivedi. Acta Mrtall..1986. Vol. 34.823～830
[59] 胡汉起．金属凝固原理。机械工业出版社．1999．111～112
[60] J. D. Hunt. Meter. Sci. Engny. 1984(65). 75
[61] 杨全，张真．金属凝固与铸造过程数值模拟．浙江大学出版社．1994．21～32
[62] 赵忠．金属材料与热处理．机械工业出版社．1985．56～58
[63] 《砂型铸造工艺及工装设计》联合编写组．砂型铸造工艺及工装设计．北京出版社．1979，74
[2] J. Forsund. Giesserei. 1962(14).51
[3] 柳百成。铸造工艺CAD凝固过程数值模拟分析研究。内部资料．1992
[4] Pikin J E J.Methoding in a 3D CAD Environgment. Foundry Management&Technology. Nov. 1992. 26～28
[5] Editor.Improving the Benefits of Foundries Through the New MAGMASOFT Release3.3.5. Foundryman. june 1997.206～207
[6] Jolly M.R. Cast Benefits Solidification Simulation to Foundry Trade Journal. Oct .6 1989. 744～750
[7] Kreziak G. Low Pressure Permanent Mould Process Simulation of a thin Wall Aluminum casting Materials Science and Engineering.Dec. 20.1993.255～259
[8] Editor.Simulor Software Achieves 10 Years Maturity.Foundry Trade.j.july 1994.325～326
[9] Esrin.L.A. Deeper Look at Casting Solidification Software. Modern Casting. July 1994 20～24
[10] Cope M A. Metal Flow Design Concept .May 1995
[11] Manual of Procast. UES Corporation. 1996
[12] Nagasaka, Y, Linguchi, S.,Nachi. M. and Brimacombe, J.K.,AFS Trans.,1989(117).554
[13] Marrone R.E. Numerical Simulation of Solidification Part I. Low Carbon Steel Casting-L.Shape. AFS Casting Metals Research Journal. 1970(12).184～192
[14] Hou T X. Computation of Solidification of a Steel Casting Against a Chill Mold Wall. Afs Trans. 1988.151～160
[15] Hansen P N. Solidification and Casting of Metals. Arrow Smith Loct. London. 177.350～361
[16] 姚山。大型铸钢齿轮三维有限差分的计算机自动剖分及凝固数值模拟．铸造．1995(2)．6～11
[17] 郭可仞．大型铸件凝固过程数值模拟．大连工学院学报．1980．19(1)．1～16
[18] Ohnaka I. Calculation of Solidification of Casting by Matrix Method. Trans. Iron Steel Inst. Japa. 1977.410～418
[19] 朱宪华．用直接差分法机械凝固过程数值解析．西安交通大学学报．1983(2)．49～60
[20] 徐东．铸件凝固过程温度场数值模拟及缩孔缩松预测实用软件开发．铸造，1988(2)1～8
[21] 大中逸雄．计算机传热凝固解析入门．机械工业出版社．1988
[22] Brown S G.A Rapid Alternative to Solidification Modelling. Modern Casting. Dec. a993.24～25
[23] Wen S W. Simulation of a Automobile Wheel Casting Process. Proceedings of the 61st World Foundy Congress. Sept. 1995. Bei jing. 524～552
[24] 裴清祥．铸造充型过程三维数值模拟及铸造工艺CAD系统的研究。[博士学位论文]．北京：清华大学．1991．1
[25] 荆涛．三维集成铸造工艺CAD／CAE系统研究．[博士学位论文]．北京：清华大学．1993．5
[26] 高志强．铸造过程流场温度场三维数值模拟．[博士学位论文]．北京：清华大学．1995．5
[27] 常庆明．大型薄壁铸件三维充型几何传热的数值模拟．[博士学位论文]．哈尔滨：哈尔滨工业大学．1985
[28] Chen J H. Comparison on Different Modes of Latent Heat Release for Modeling Csting Solidificatinon. AFS Trans.1990 539～546
[29] 贾宝仟．铸钢件的热裂预测及其数值模拟．[博士学位论文]．北京：清华大学．1996
[30] W.Oldfield, A Quatitative Approach to Casting Solidification. Freezing of Cast Iron, ASM Trans..1966(59).945～961
[31] D.M. Stefanescu, C.S. Kanetkav. AFS Trans..1987(95).139～144
[32] I.Minkoff. the Foundryman. 1993(1、2).16～22
[33] D. Dgoettsch and J.A. Dantzig. Metallurgical and Materials Transactiong. 1994(25A).1063～1079
[34] J. ZouandM. Rappaz. The Minerals, Metals&Materials Society .1991.335～36O
[35] ph. Thevoz, J.L. Desbioles and M. Rappaz. Metall. Trans. 1989(20AO. 311～322
[36] M. Castro, J. Lacaze, N. Aichoun and G. Lescoult. Memoirres et Etudes Scientifiquess Revue de Metallurgie. 1989(2).85～97
[37] M.P. Anderson, D.J. Srolovitz, G. Sgrest, and P.S Sahni. Acta Metall.1984(32).783
[38] J. A. Spittle and S.G. Brown. Acta Metal11989(37).1803
[39] P. Zhu and W. Smith. Acta Metall.1992(40).3369
[40] Ch-A. GANDIA and M. Rappaz..Acta metal mater. 1994. vol. 42.2233～2246
[41] W. kurz, B.Giovanota and R. Trived. Acta Metall.1986(34).823
[42] R. Trivedi, P. Magin and W. Kurz. Acta Metall. 1987(35).971
[43] C. W. Price. Acta Metall. 1987(35).1377
[44] M. Rappaz. Imt Mater. Rev. 1989(34).93
[45] Ph. Thevoz, J-L. Desbiolles, M. Rappaz. Metall.Trans.,20A(1989).311～322
[46] Wang. C. Y, Beckermann. C. Metall. Trans. A, 1993,24A 2787～2802
[47] Wang. C. Y, Beckermann. C. Metall. Trans. A, 1993,26B 111～119
[48] Ph. Thevoz, J-L. Desbiolles, M. Rappaz. Light Metals.,Ed. By Ch.M. Bickkert, TMS 1990,975～984
[49] M.M' Hamdi, Hcombeau, G. Lesoult. Numerical Modeling of the Coloumnar to Equiaxed Transition in Continous Casting of Steel. Modeling of Casting, Welding and Advanced Solidification Processes VIII, Ed. By G. Thomas and C. Beckermann, TMS, Warrendale, Pennsylvania, USA(1998),375～382
[50] M. Rappaz and E. Biank. J. Cryst. Grith. 1986(74).67
[51] W. Oldfield.A Quantitative Approach to Casting Solidification:Freezing of Cast Iron. ASM Trans.,59,1966,945～960
[52] J.-L. Desbiolles, Ch.-A. Gandin, J.-F. Joyeux, M. Rappaz and Ph. Thevoz. A 3DCAFE Model for the Predication of Solidification of Grain Structures. Modeling of Casting, Welding and Advanced Solidification Processes Ⅷ.1998,433～440
[53] Warren J A, Boettinger W J, Prediction of dendritic growth and microsegregztion patterns in a binary alloy using the phase-field method [J]. Physical Review A, 1991,43(100:1310～1317
[54] I.Steinbach, G.J. Schmitz. Three Dimensinal Modeling of Equiaxed Dentritic Growth on a Messoscopic Scale. Acta Mater.,47(1999):971～982
[55] 胡汉起．金属凝固．冶金工业出版社．1985
[56] 侯增寿，卢光熙．金属学原理．上海科学技术出版社．1990
[57] J. Lipton, W. kurz, and R. Trivedi. Acta Metall..1987. Vol. 35.957～964
[58] W. Kurz, B. givonaola and R. Trivedi. Acta Mrtall..1986. Vol. 34.823～830
[59] 胡汉起．金属凝固原理。机械工业出版社．1999．111～112
[60] J. D. Hunt. Meter. Sci. Engny. 1984(65). 75
[61] 杨全，张真．金属凝固与铸造过程数值模拟．浙江大学出版社．1994．21～32
[62] 赵忠．金属材料与热处理．机械工业出版社．1985．56～58
[63] 《砂型铸造工艺及工装设计》联合编写组．砂型铸造工艺及工装设计．北京出版社．1979，74