Ti（C，N）基金属陶瓷粉末注射成形原理模型及工艺研究
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摘要
Ti(C,N)基金属陶瓷是用于取代硬质合金的高性能硬质材料。通过粉末注射成形的方法可以制得比传统模压成型形状更为复杂的Ti(C,N)基金属陶瓷产品,从而拓宽Ti(C,N)基金属陶瓷材料的应用范围。由于Ti(C,N)基金属陶瓷材料成分体系复杂,各组分理化性能特殊,在粉末注射成形研究中缺少一套较为完备的理论模型,该类模型的研究对Ti(C,N)基金属陶瓷粉末注射成形工艺的改进和计算机模拟有十分重大的理论和实际意义。
本文结合国内外粉末注射成形理论模型研究成果和本课题组对Ti(C,N)基金属陶瓷粉末注射成形研究所取得的一些成果以及遇到的一些问题,开展对该课题的研究。通过测定粘结剂各组元之间的热学性能(熔化温度和失重曲线),计算热力学相容性,测试改进型粘结剂的流变性能,优化注射参数,进行溶剂-热脱脂两步脱脂法实验以及对比三种不同的烧结工艺,探索了使用添加了油酸的改进型粘结剂的Ti(C,N)基金属陶瓷粉末注射成形工艺,最终获得试样的最佳性能为:抗弯强度805MPa,硬度84.5HRA,密度6.62g/cm3。
基于实验室以前对Ti(C,N)基金属陶瓷粉末注射成形粉体的各项性能测试,拟合了Ti(C,N)基金属陶瓷粉末注射成形所用粉末的体心立方堆垛结构。通过压力传递模型和粘结剂包覆层模型的推导,修正了Ti(C,N)基金属陶瓷粉末注射成形的粉末最佳装载量模型。基于German教授提出的标准模型,结合课题组之前测得的一些喂料流变性能相关参数以及本文之前所建立的喂料结构模型,通过VB语言编写了粉末注射成形流变性能预测软件,较好地拟合了Ti(C,N)基金属陶瓷粉末注射成形喂料流变性能的理论与实际值,为日后的计算机模拟奠定了基础。
利用菲克第二定律和高分子溶胀-溶解两步原理模型,建立和编程模拟了溶剂脱脂溶解限制模型,解释了溶剂脱脂出现的表面裂纹和可溶性组分脱除过程。通过建立热脱脂过程中粉末流动模型,解释了Ti(C,N)基金属陶瓷粉末注射成形典型的分层裂纹缺陷并提出了解决方案。
Ti(C,N)-based cermets used to substitute for cemented carbide is an advanced hard material. Products of Ti(C,N)-based cermets with more complex shape can be obtained by powder injection molding(PIM) than by traditional pressure molding, this expands the range of application of Ti(C,N)-based cermets material. Because the system of ingredients of Ti(C,N)-based cermets is complex and the physical chemical properties of each ingredient is special, there is not an integrated theory model on the powder injection molding. Therefore these types of models are important for theory and practice on improvement of process and computer simulation.
This paper develops the study by connecting the achievements of theories on PIM at home and abroad and some results and problems of research on Ti(C,N)-based cermets PIM in our laboratory. The processes of Ti(C,N)-based cermets PIM with modified binder is explored by measuring thermal properties (melting point and weight-loss curve) of each component of the binders, calculating thermodynamics compatibility, testing rheological behavior of modified binder, optimizing the parameters in PIM, completing solvent-thermal two steps debinding experiment, and comparing three types of sintering processes. The best property of sintered patterns in this work is bending strength 805MPa, hardness 84.5 HRA, density 6.62 finally.
Based on the results of properties tests on the Ti(C,N)-based cermets PIM in our lab before, body center cubic(BCC) stack structure of powders of Ti(C,N)-based cermets is matched. The best solid loading capacity model is modified by deducing from the pressure-transmission model and binder-coating model. Based on standard model presented by Professor German, connecting the related parameters of rheological behavior of feedstock and structure model of feedstock in the paper, the PIM rheological behavior of feedstock forecasting software, which can fit the values of theories and practice of rheological behavior of feedstock in Ti(C,N)-based cermets PIM, is compiled with VB language. The series of models and software establish some foundations for computer simulation in future.
Solvent debinding dissolution constraint model is established and simulated with Fick's second law and macromolecule swelling-dissolving two steps theory model. Furthermore, the reasons of surface cracks from solvent debinding and the extraction process of dissoluble components are explained by the latest model. The typical layer-crack defect of Ti(C,N)-based cermets PIM is explained by establishing a powder-flowing model during thermal debinding process, and the settle method is presented.
本文结合国内外粉末注射成形理论模型研究成果和本课题组对Ti(C,N)基金属陶瓷粉末注射成形研究所取得的一些成果以及遇到的一些问题,开展对该课题的研究。通过测定粘结剂各组元之间的热学性能(熔化温度和失重曲线),计算热力学相容性,测试改进型粘结剂的流变性能,优化注射参数,进行溶剂-热脱脂两步脱脂法实验以及对比三种不同的烧结工艺,探索了使用添加了油酸的改进型粘结剂的Ti(C,N)基金属陶瓷粉末注射成形工艺,最终获得试样的最佳性能为:抗弯强度805MPa,硬度84.5HRA,密度6.62g/cm3。
基于实验室以前对Ti(C,N)基金属陶瓷粉末注射成形粉体的各项性能测试,拟合了Ti(C,N)基金属陶瓷粉末注射成形所用粉末的体心立方堆垛结构。通过压力传递模型和粘结剂包覆层模型的推导,修正了Ti(C,N)基金属陶瓷粉末注射成形的粉末最佳装载量模型。基于German教授提出的标准模型,结合课题组之前测得的一些喂料流变性能相关参数以及本文之前所建立的喂料结构模型,通过VB语言编写了粉末注射成形流变性能预测软件,较好地拟合了Ti(C,N)基金属陶瓷粉末注射成形喂料流变性能的理论与实际值,为日后的计算机模拟奠定了基础。
利用菲克第二定律和高分子溶胀-溶解两步原理模型,建立和编程模拟了溶剂脱脂溶解限制模型,解释了溶剂脱脂出现的表面裂纹和可溶性组分脱除过程。通过建立热脱脂过程中粉末流动模型,解释了Ti(C,N)基金属陶瓷粉末注射成形典型的分层裂纹缺陷并提出了解决方案。
Ti(C,N)-based cermets used to substitute for cemented carbide is an advanced hard material. Products of Ti(C,N)-based cermets with more complex shape can be obtained by powder injection molding(PIM) than by traditional pressure molding, this expands the range of application of Ti(C,N)-based cermets material. Because the system of ingredients of Ti(C,N)-based cermets is complex and the physical chemical properties of each ingredient is special, there is not an integrated theory model on the powder injection molding. Therefore these types of models are important for theory and practice on improvement of process and computer simulation.
This paper develops the study by connecting the achievements of theories on PIM at home and abroad and some results and problems of research on Ti(C,N)-based cermets PIM in our laboratory. The processes of Ti(C,N)-based cermets PIM with modified binder is explored by measuring thermal properties (melting point and weight-loss curve) of each component of the binders, calculating thermodynamics compatibility, testing rheological behavior of modified binder, optimizing the parameters in PIM, completing solvent-thermal two steps debinding experiment, and comparing three types of sintering processes. The best property of sintered patterns in this work is bending strength 805MPa, hardness 84.5 HRA, density 6.62 finally.
Based on the results of properties tests on the Ti(C,N)-based cermets PIM in our lab before, body center cubic(BCC) stack structure of powders of Ti(C,N)-based cermets is matched. The best solid loading capacity model is modified by deducing from the pressure-transmission model and binder-coating model. Based on standard model presented by Professor German, connecting the related parameters of rheological behavior of feedstock and structure model of feedstock in the paper, the PIM rheological behavior of feedstock forecasting software, which can fit the values of theories and practice of rheological behavior of feedstock in Ti(C,N)-based cermets PIM, is compiled with VB language. The series of models and software establish some foundations for computer simulation in future.
Solvent debinding dissolution constraint model is established and simulated with Fick's second law and macromolecule swelling-dissolving two steps theory model. Furthermore, the reasons of surface cracks from solvent debinding and the extraction process of dissoluble components are explained by the latest model. The typical layer-crack defect of Ti(C,N)-based cermets PIM is explained by establishing a powder-flowing model during thermal debinding process, and the settle method is presented.
引文
[1]贺从训,夏志华,汪有明等. Ti(C,N)基金属陶瓷的研究.稀有金属, 1999, 23(1): 4～12
[2]刘宁,胡镇华,崔崑.钇对金属陶瓷力学性能和组织的影响.中国稀土学报, 1997, 15(1): 80～82
[3] F. Qi, S. Kang. A study on microstructural changes in Ti(C,N)–NbC–Ni cermets. Materials Science and Engineering, 1998, 25(1): 276～285
[4] P. Ettmayer, H. kolaska, W. Lengauer. Ti(C,N)cermets metallurgy and properties. RM&HM, 1995(13): 343～347
[5] F. Monteverde, V. Medri, A. Bellosi. Microstructure of hot-pressed Ti(C,N)-based cermets. Journal of the European Ceramic Society, 2002(22): 2587～2593
[6] J. Jung, S. Kang. Effect of ultra-fine powders on the microstructure of Ti(CN)–xWC–Ni cermets. Acta Materialia, 2004(52): 1379～1386
[7]刘宁,赵兴中,邓宗钢等.钢和铸铁激光相变硬化层的残余应力研究.机械工程学报, 1994, 30(3): 93～96
[8]刘宁,赵兴中.添加碳对Ti(C,N)基金属陶瓷组织和性能的影响.理化检验, 1995, 31(2): 13～15
[9] M. Humenik, M. Parikh. Fundamental concepts related to microstructure and physical properties of cermet systems. J. Amer. Geram. soc, 1956, 39(2): 60～66
[10]铃木寿,林宏尔,松原秀彰.日本金属学会会报, 1983, 22(4): 312～315
[11]松原秀彰,富士原由雄.日本金属学会会报, 1990, 29(12): 1008～1012
[12]曲选辉,颜寒松,黄伯云.金属粉末注射成形粘结剂的发展.粉末冶金技术, 1997, 15(1): 61～63
[13] R. M. German. Powder injection molding. vol. 1. Princeton: MPIF, 1990
[14] K. Schwartzwalder. Injection molding of ceramic materials. Ceramic Bulletin,1949(28): 459～461
[15] S. Yerazunis, J. W. Bartlett, A. H. Nissan. Packing of binary mixtures of spheres and irregular particles. Nature, 1962(195): 33～40
[16] H. Y. Sohn, C. Moreland. The effect of particle size distribution on packing density. Canadian Journal of Chemical Engineering, 1968(46): 162～167
[17] H. Bennett. Industrial waxes. vol. 1. NY: Chemical Publishing, 1963
[18] G. D. Scott. Packing of equal spheres. Nature, 1960(188): 908～909
[19] R. M. German. Optimization of the powder-binder mixture for powder injection molding. Advances in Powder Metallurgy, 1989(3): 51～66
[20] N. H. Loh, R.M. German. Statistical analysis of shrinkage variation for powder injection molding. Journal of materials processing technology, 1996(59): 278～284
[21] M. Dutilly, O. Ghouati, J. C. Gelin. Finite-element analysis of the debinding and densification phenomena in the process of metal injection molding. Journal of materials processing technology, 1998(83): 170～175
[22] W. J. Tseng. Statistical analysis of process parameters influencing dimensional control in ceramic injection molding. Journal of materials processing technology, 1998(79): 242～250
[23] D. S. Tsai, W. W. Chen. Solvent debinding kinetics of alumina green bodies by powder injection molding. Ceramics International, 1995, 21: 257～264
[24] B. Zhu, X. H. Qu, Y. Tao. Mathematical model for condensed-solvent debinding process of PIM. Journal of materials processing technology, 2003(142): 487～492
[25] Z. P. Xie, J. S. Luo, X. Wang. The effect of organic vehicle on the injection molding of ultra-fine zirconia powders. Materials and Design, 2005(26): 79～82
[26]李昆,李晓明,李笃信等.表面活性剂对MIM硬质合金粘结剂和喂料性质的影响.材料科学与工程, 2002, 20(12): 248～250
[27]李松林,黄伯云,曲选辉等.表面活性剂对金属粉末注射成形喂料性能的影响.稀有金属材料与工程, 2001, 30(2): 131～133
[28] W. J. Tseng, D. M. Liu, Chung-King Hsu, Influence of stearic acid on suspension structure and green microstructure of injection-molded zirconia ceramics. Ceramics International, 1999(25): 191～195
[29] W. J. Tseng. Influence of surfactant on rheological behaviors of injection–molded alumina suspensions. Materials Science and Engineering, 2000(A289): 116～122
[30]范畴. Ti(C,N)基金属陶瓷粉末注射成形工艺的研究: (博士学位论文)武汉:华中科技大学图书馆, 2006
[31] S. Li, B. Huang, Yimin Li. A new type of binder for metal injection molding. Journal of Materials Processing Technology, 2003(137): 70～73
[32]张留成,瞿雄伟,丁会利编著.高分子材料基础.北京:化学工业出版社, 2002
[33]魏京. TI(C,N)基金属陶瓷粉末注射成形的研究: (硕士学位论文)武汉:华中科技大学图书馆, 2005
[34] (苏)伐因斯坦著.现代晶体学(第一卷).吴自勤译.合肥:中国科学技术大学出版社, 1990
[35] C. Jin. Preparation of ultrafine TiC-Ni cermet powder by mechanical alloying. Journal of Materials Processing Technology, 2000(104): 127～132
[36] Z. Y. Liu, N. H. Loh, S. B. Tor. Characterization of powder injection molding feedstock. Materials Characterization, 2003(49): 313～320
[37] J. Warrem, R. M. German. The effect of powder characteristics on binder incorporation for injection molding feedstock. Modern Developments in Powder Metallurgy, 1988(18): 391～402
[38] M. J. Edirisinghe, J. R. G. Evans. Rheology of ceramic injection moulding formulations. British Ceramic Society Transactions and Journal, 1987(86): 18～22
[39] S. L. Li, Y. M. Li, B. Huang. Development of a solvent-debound Wax-oil-PE binder for MIM. Powder Metallurgy Technology, 2001(4): 204～207
[40] S. Krug, J. R. G. Evans, J. H. H. ter Maat. Residual stresses and cracking in large ceramic injection mouldings subjected to different solidification schedules. Journal ofthe European Ceramic Society, 2000(20): 2535～2541
[41] M. R. Kamal, P. G. Lafleur. Computer simulation of injection molding. Polymer Engineering and Science, 1982(22): 1066～1074
[42]吴培熙,张留成编著.聚合物共混改性.中国轻工业出版社, 1996
[43]严明双. Ti(C,N)基金属陶瓷粉末注射成形工艺的研究: (硕士学位论文)武汉:华中科技大学图书馆, 2006
[44] Z. M. Allawi, D. J. Gunn. Flow and diffusion of gases through porous substrates. American Institute of Chemical Engineers Journal, 1987(33): 766～775
[45] M. Trunec, J. Cihlar. Thermal debinding of injection moulded ceramics. Journal of the European Ceramic Society, 1997(17): 203～209
[46] H. M. Shaw, M. J. Edirisinghe. Shrinkage and particle packing during removal of organic vehicle from ceramic injection mouldings. Journal of the European Ceramic Society, 1995(15): 109～116
[47]黄培云编著.粉末冶金原理.北京:冶金工业出版社, 1982
[48]刘文俊,郑勇,游敏.烧结温度对细晶粒Ti(C,N)基陶瓷组织和性能的影响.三峡大学学报, 2003, 25(2): 114～117
[49]郑勇,游敏,刘文俊等.原始粉末尺寸对Ti(C,N)基金属陶瓷烧结特性和组织结构的影响.粉末冶金技术, 2003, 21(4): 195～200
[2]刘宁,胡镇华,崔崑.钇对金属陶瓷力学性能和组织的影响.中国稀土学报, 1997, 15(1): 80～82
[3] F. Qi, S. Kang. A study on microstructural changes in Ti(C,N)–NbC–Ni cermets. Materials Science and Engineering, 1998, 25(1): 276～285
[4] P. Ettmayer, H. kolaska, W. Lengauer. Ti(C,N)cermets metallurgy and properties. RM&HM, 1995(13): 343～347
[5] F. Monteverde, V. Medri, A. Bellosi. Microstructure of hot-pressed Ti(C,N)-based cermets. Journal of the European Ceramic Society, 2002(22): 2587～2593
[6] J. Jung, S. Kang. Effect of ultra-fine powders on the microstructure of Ti(CN)–xWC–Ni cermets. Acta Materialia, 2004(52): 1379～1386
[7]刘宁,赵兴中,邓宗钢等.钢和铸铁激光相变硬化层的残余应力研究.机械工程学报, 1994, 30(3): 93～96
[8]刘宁,赵兴中.添加碳对Ti(C,N)基金属陶瓷组织和性能的影响.理化检验, 1995, 31(2): 13～15
[9] M. Humenik, M. Parikh. Fundamental concepts related to microstructure and physical properties of cermet systems. J. Amer. Geram. soc, 1956, 39(2): 60～66
[10]铃木寿,林宏尔,松原秀彰.日本金属学会会报, 1983, 22(4): 312～315
[11]松原秀彰,富士原由雄.日本金属学会会报, 1990, 29(12): 1008～1012
[12]曲选辉,颜寒松,黄伯云.金属粉末注射成形粘结剂的发展.粉末冶金技术, 1997, 15(1): 61～63
[13] R. M. German. Powder injection molding. vol. 1. Princeton: MPIF, 1990
[14] K. Schwartzwalder. Injection molding of ceramic materials. Ceramic Bulletin,1949(28): 459～461
[15] S. Yerazunis, J. W. Bartlett, A. H. Nissan. Packing of binary mixtures of spheres and irregular particles. Nature, 1962(195): 33～40
[16] H. Y. Sohn, C. Moreland. The effect of particle size distribution on packing density. Canadian Journal of Chemical Engineering, 1968(46): 162～167
[17] H. Bennett. Industrial waxes. vol. 1. NY: Chemical Publishing, 1963
[18] G. D. Scott. Packing of equal spheres. Nature, 1960(188): 908～909
[19] R. M. German. Optimization of the powder-binder mixture for powder injection molding. Advances in Powder Metallurgy, 1989(3): 51～66
[20] N. H. Loh, R.M. German. Statistical analysis of shrinkage variation for powder injection molding. Journal of materials processing technology, 1996(59): 278～284
[21] M. Dutilly, O. Ghouati, J. C. Gelin. Finite-element analysis of the debinding and densification phenomena in the process of metal injection molding. Journal of materials processing technology, 1998(83): 170～175
[22] W. J. Tseng. Statistical analysis of process parameters influencing dimensional control in ceramic injection molding. Journal of materials processing technology, 1998(79): 242～250
[23] D. S. Tsai, W. W. Chen. Solvent debinding kinetics of alumina green bodies by powder injection molding. Ceramics International, 1995, 21: 257～264
[24] B. Zhu, X. H. Qu, Y. Tao. Mathematical model for condensed-solvent debinding process of PIM. Journal of materials processing technology, 2003(142): 487～492
[25] Z. P. Xie, J. S. Luo, X. Wang. The effect of organic vehicle on the injection molding of ultra-fine zirconia powders. Materials and Design, 2005(26): 79～82
[26]李昆,李晓明,李笃信等.表面活性剂对MIM硬质合金粘结剂和喂料性质的影响.材料科学与工程, 2002, 20(12): 248～250
[27]李松林,黄伯云,曲选辉等.表面活性剂对金属粉末注射成形喂料性能的影响.稀有金属材料与工程, 2001, 30(2): 131～133
[28] W. J. Tseng, D. M. Liu, Chung-King Hsu, Influence of stearic acid on suspension structure and green microstructure of injection-molded zirconia ceramics. Ceramics International, 1999(25): 191～195
[29] W. J. Tseng. Influence of surfactant on rheological behaviors of injection–molded alumina suspensions. Materials Science and Engineering, 2000(A289): 116～122
[30]范畴. Ti(C,N)基金属陶瓷粉末注射成形工艺的研究: (博士学位论文)武汉:华中科技大学图书馆, 2006
[31] S. Li, B. Huang, Yimin Li. A new type of binder for metal injection molding. Journal of Materials Processing Technology, 2003(137): 70～73
[32]张留成,瞿雄伟,丁会利编著.高分子材料基础.北京:化学工业出版社, 2002
[33]魏京. TI(C,N)基金属陶瓷粉末注射成形的研究: (硕士学位论文)武汉:华中科技大学图书馆, 2005
[34] (苏)伐因斯坦著.现代晶体学(第一卷).吴自勤译.合肥:中国科学技术大学出版社, 1990
[35] C. Jin. Preparation of ultrafine TiC-Ni cermet powder by mechanical alloying. Journal of Materials Processing Technology, 2000(104): 127～132
[36] Z. Y. Liu, N. H. Loh, S. B. Tor. Characterization of powder injection molding feedstock. Materials Characterization, 2003(49): 313～320
[37] J. Warrem, R. M. German. The effect of powder characteristics on binder incorporation for injection molding feedstock. Modern Developments in Powder Metallurgy, 1988(18): 391～402
[38] M. J. Edirisinghe, J. R. G. Evans. Rheology of ceramic injection moulding formulations. British Ceramic Society Transactions and Journal, 1987(86): 18～22
[39] S. L. Li, Y. M. Li, B. Huang. Development of a solvent-debound Wax-oil-PE binder for MIM. Powder Metallurgy Technology, 2001(4): 204～207
[40] S. Krug, J. R. G. Evans, J. H. H. ter Maat. Residual stresses and cracking in large ceramic injection mouldings subjected to different solidification schedules. Journal ofthe European Ceramic Society, 2000(20): 2535～2541
[41] M. R. Kamal, P. G. Lafleur. Computer simulation of injection molding. Polymer Engineering and Science, 1982(22): 1066～1074
[42]吴培熙,张留成编著.聚合物共混改性.中国轻工业出版社, 1996
[43]严明双. Ti(C,N)基金属陶瓷粉末注射成形工艺的研究: (硕士学位论文)武汉:华中科技大学图书馆, 2006
[44] Z. M. Allawi, D. J. Gunn. Flow and diffusion of gases through porous substrates. American Institute of Chemical Engineers Journal, 1987(33): 766～775
[45] M. Trunec, J. Cihlar. Thermal debinding of injection moulded ceramics. Journal of the European Ceramic Society, 1997(17): 203～209
[46] H. M. Shaw, M. J. Edirisinghe. Shrinkage and particle packing during removal of organic vehicle from ceramic injection mouldings. Journal of the European Ceramic Society, 1995(15): 109～116
[47]黄培云编著.粉末冶金原理.北京:冶金工业出版社, 1982
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