Supercritical Carbon Dioxide Debinding in Metal Injection Molding (MIM) Process

Yong-Ho Kim; Youn-Woo Lee; Jong-Ku Park; Chang-Ha Lee; Jong Sung Lim

Korean Journal of Chemical Engineering, Vol.19, No.6, 986-991, November, 2002

DOI10.1007/BF02707221 Export Citation

Supercritical Carbon Dioxide Debinding in Metal Injection Molding (MIM) Process

Yong-Ho Kim , Youn-Woo Lee , Jong-Ku Park¹, Chang-Ha Lee², and Jong Sung Lim^†

National Research Lab. for Supercritical Fluid, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea
¹Ceramic Processing Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea
²Dept. of Chem. Eng., Yonsei University, 134 Shinchon-dong, Sudaemoon-ku, Seoul 120-749, Korea

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The conventional debinding process in metal injection molding (MIM) is critical, environmentally unfriendly and time consuming. On the other hand, supercritical debinding is thought to be an effective method appropriate for eliminating the aforementioned inconvenience in the prior art. In this paper, supercritical debinding is compared with the conventional wicking debinding process. The binder removal rates in supercritical CO2 have been measured at 333.15 K, 348.15 K, and 358.15 K in the pressure range from 20 MPa to 28 MPa. After sintering, the surface of the silver bodies were observed by using SEM. When the supercritical CO2 debinding was carried out at 348.15 K, all the paraffin wax (71 wt% of binder mixture) was removed in 2 hours under 28 MPa and in 2.5 hours under 25 MPa. We also studied the cosolvent effects on the binder removal rate in the supercritical CO2 debinding. It was found that the addition of non-polar cosolvent (n-hexane) dramatically improves the binder removal rate (more than 2 times) for the paraffin wax-based binder system.

Keywords:Supercritical CO2 Debinding;Metal Injection Molding (MIM);Binder;Diffusivity;Cosolvent

[References]

Angus S, Armstrong A, deReuk KM, "Carbon Dioxide. International Thermodynamic Tables of the Fluid State," Pergamon, Oxford (1976)
Chartier T, Delhomme E, Baumard JF, Marteau P, Subra P, Tufeu R, Ind. Eng. Chem. Res., 38(5), 1904 (1999)
Chartier T, Ferrato M, Baumard JF, J. Am. Ceram. Soc., 78, 1787 (1995)
Chartier T, Ferrato M, Baumard JF, J. Eur. Ceram. Soc., 15, 899 (1995)
Crank J, "The Mathematics of Diffusion," 2nd ed., Oxford University Press, Oxford (1975)
Dobbs JM, Wong JM, Lahiere RJ, Johnston KP, Ind. Eng. Chem. Res., 26, 56 (1987)
Foster NR, Singh H, JimmyYun SL, Tomasko DL, Macnaughton SJ, Ind. Eng. Chem. Res., 32, 2849 (1993)
German RM, Int. J. Powder Metall., 23, 237 (1987)
Hens KF, "Process Analysis of Injection Molding with Powder Mixtures," Ph.D. Thesis, Rensselaer Polytechnic Institute, New York (1990)
McHugh MA, Krukonis VJ, "Supercritical Fluid Extraction, Principles and Practice," 2nd ed., Butterworth-Heinemann, Boston, 15 (1994)
Milke EC, Schaeffer L, Souza JP, Adv. Powder Technol., 636 (2001)
Muthukumaran P, Gupta RB, Sung HD, Shim JJ, Bae HK, Korean J. Chem. Eng., 16(1), 111 (1999)
Nashikawa E, Wakao N, Nakashima N, J. Supercrit. Fluids, 4, 265 (1991)
Noh MJ, Kim TG, Hong IK, Yoo KP, Korean J. Chem. Eng., 12(1), 48 (1995)
Rei M, Souza JP, Schaeffer L, Adv. Powder Technol., 616 (2001)
Shewmon PG, "Diffusion in Solids," McGraw-Hill Book Company, U.S. (1963)
Shivashankar TS, German RM, J. Am. Ceram. Soc., 82, 1146 (1999)
Shimizu T, Mochizuki S, Sano T, Fuchizawa S, P.P. Metall., 43, 1188 (1996)
Takishima S, Matsumoto H, Nagasaki H, Masuoka H, Mukai Y, Sakai Y, Kag. Kog. Ronbunshu, 17, 243 (1991)
Taylor LT, "Supercritical Fluid Extraction," John Wiley & Sons, Inc. (1996)
Tam KC, Yap SP, Foong ML, Loh NH, J. Mater. Process. Tech., 67, 120 (1997)

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[1] Angus S, Armstrong A, deReuk KM, "Carbon Dioxide. International Thermodynamic Tables of the Fluid State," Pergamon, Oxford (1976)

[2] Chartier T, Delhomme E, Baumard JF, Marteau P, Subra P, Tufeu R, Ind. Eng. Chem. Res., 38(5), 1904 (1999)

[3] Chartier T, Ferrato M, Baumard JF, J. Am. Ceram. Soc., 78, 1787 (1995)

[4] Chartier T, Ferrato M, Baumard JF, J. Eur. Ceram. Soc., 15, 899 (1995)

[5] Crank J, "The Mathematics of Diffusion," 2nd ed., Oxford University Press, Oxford (1975)

[6] Dobbs JM, Wong JM, Lahiere RJ, Johnston KP, Ind. Eng. Chem. Res., 26, 56 (1987)

[7] Foster NR, Singh H, JimmyYun SL, Tomasko DL, Macnaughton SJ, Ind. Eng. Chem. Res., 32, 2849 (1993)

[8] German RM, Int. J. Powder Metall., 23, 237 (1987)

[9] Hens KF, "Process Analysis of Injection Molding with Powder Mixtures," Ph.D. Thesis, Rensselaer Polytechnic Institute, New York (1990)

[10] McHugh MA, Krukonis VJ, "Supercritical Fluid Extraction, Principles and Practice," 2nd ed., Butterworth-Heinemann, Boston, 15 (1994)

[11] Milke EC, Schaeffer L, Souza JP, Adv. Powder Technol., 636 (2001)

[12] Muthukumaran P, Gupta RB, Sung HD, Shim JJ, Bae HK, Korean J. Chem. Eng., 16(1), 111 (1999)

[13] Nashikawa E, Wakao N, Nakashima N, J. Supercrit. Fluids, 4, 265 (1991)

[14] Noh MJ, Kim TG, Hong IK, Yoo KP, Korean J. Chem. Eng., 12(1), 48 (1995)

[15] Rei M, Souza JP, Schaeffer L, Adv. Powder Technol., 616 (2001)

[16] Shewmon PG, "Diffusion in Solids," McGraw-Hill Book Company, U.S. (1963)

[17] Shivashankar TS, German RM, J. Am. Ceram. Soc., 82, 1146 (1999)

[18] Shimizu T, Mochizuki S, Sano T, Fuchizawa S, P.P. Metall., 43, 1188 (1996)

[19] Takishima S, Matsumoto H, Nagasaki H, Masuoka H, Mukai Y, Sakai Y, Kag. Kog. Ronbunshu, 17, 243 (1991)

[20] Taylor LT, "Supercritical Fluid Extraction," John Wiley & Sons, Inc. (1996)

[21] Tam KC, Yap SP, Foong ML, Loh NH, J. Mater. Process. Tech., 67, 120 (1997)