Kovar合金的粉末注射成形工艺研究
|
摘要
Kovar合金具有较低的热膨胀系数，可与陶瓷，玻璃等材料进行封接，已广泛应用于微电子和光纤通信领域。本文采用毛细管流变仪和热重分析仪分别研究了粉末喂料的流变行为和成形性的脱脂规律。采用扫描电镜与热膨胀仪等现代分析手段研究了粉末注射成形Kovar合金产品的微观组织和热膨胀性能。
研究了三种蜡基多聚和物粘结剂体系喂料的流变性，通过对应变敏感性参数n的比较，得出比较适宜注射成形的是58％PW+20％CERESIN+10％EVA+10％hdpe+2％SA的喂料。对应的最佳注射工艺参数为：注射温度135℃～140℃、注射压力80％、保压压力70％、模具温度40℃。实验采用两种脱脂工艺热脱脂和溶剂脱脂，其中热脱脂在H_2气氛下进行，较理想工艺为：室温～115℃，升温时间为30分钟；115℃～350℃，升温时间为240分钟，保温时间为1小时；350℃～490℃，升温时间为30分钟，保温时间为30分钟；490℃～620℃，升温时间为30分钟，保温时间为30分钟；较理想的溶剂脱脂工艺为：将注射坯浸入三氯乙烯+乙醇+花生油的混合溶剂当中进行脱蜡，时间为13个小时，蜡组元基本脱除干净，且无变形与开裂。其后续热脱脂工艺为：室温～350℃，升温时间为100分钟，保温40分钟；350℃～430~C，升温时间为60分钟，保温60分钟；最后随炉冷却到室温。
研究了不同的烧结温度与不同的保温时间对烧结密度的影响。结
果表明，随着烧结温度的升高，保温时间的延长，烧结坯的密度明显
提高。1280℃下烧结2小时，密度可达8.13眺m，。烧结采用氢气气
氛，使得烧结坯几乎完全脱碳，这对合金的膨胀系数有着积极的影响。
研制的Kovar合金的热膨胀系数达到了国家有关标准。
Kovar alloys have a lower thermal expansion coefficient .They can be sealed with materials such as ceramics, glass. And they are widely used in the fields of microelectronics and optical fiber communication. The rheological behaviors of powder feedstocks and debinding rules of
molded compact are studied on the base of capillary rheometer and TGA. The SEM and thermal expansion analysis are used to investigate the microstructures of the parts of MIM Kovar alloys and the thermal expansion properties respetively.
The feedstocks rheology of three wax-based multi-polymer binders were investigated. Through comparison of n value (exponent used to characterize the fluid ) .The feedstock suitable for MIM was abtained:58%PW+20CERESIN+10%EVA
+10%HDPE+2%SA. The according optimum MIM process parameters were also acquired: injection temperature is between 135℃ and 140 ℃ ,molding pressure is 80%,holding pressure is 70% and mold temperature is 40 ℃ .Thermal debinding technology and solvent debinding technology were both used. And thermal debinding was under the atmosphere of H2.The ideal process was divided into four stages:(1)the temperature increases from room temperature to 115℃ in 30mins;(2) the temperature increases form 115 ℃ to 350 ℃ in 240mins and then
remains for 60mins; (3) the temperature increases from 350℃to 490℃ in 30mins and then holds 30mins; (4) the temperature increases from 490 ℃ to 650℃ in 30mins and then holds 30mins.The ideal solvent debinding process in that the injection compact is dipped into the mixture of trichlene+ethanol+peanut oil to do debinding for 13 hours. Then the following thermal debinding process is needed: the temperature increases from 350 ℃ to 430 ℃ in 60mins and then holds 60mins;thus the debinding compact cools to room temperature with the oven.
The different sintering temperatures and holding times on sintered compact density were also studied. The results show that the sintered compact density was obvious improved with the increase of sintering temperature and holding time. The compacts were sintered at the temperature of 1280℃ for two hours and their densities were increased to 8.13g/cm3.Sintered under the atmosphere of H2,the carbon in the sintered compact was almost eliminated. This has a positive effect on the expansion coefficient of alloys.
The thermal expansion coefficients of Kovar alloys meet the requirement of GB.
研究了三种蜡基多聚和物粘结剂体系喂料的流变性，通过对应变敏感性参数n的比较，得出比较适宜注射成形的是58％PW+20％CERESIN+10％EVA+10％hdpe+2％SA的喂料。对应的最佳注射工艺参数为：注射温度135℃～140℃、注射压力80％、保压压力70％、模具温度40℃。实验采用两种脱脂工艺热脱脂和溶剂脱脂，其中热脱脂在H_2气氛下进行，较理想工艺为：室温～115℃，升温时间为30分钟；115℃～350℃，升温时间为240分钟，保温时间为1小时；350℃～490℃，升温时间为30分钟，保温时间为30分钟；490℃～620℃，升温时间为30分钟，保温时间为30分钟；较理想的溶剂脱脂工艺为：将注射坯浸入三氯乙烯+乙醇+花生油的混合溶剂当中进行脱蜡，时间为13个小时，蜡组元基本脱除干净，且无变形与开裂。其后续热脱脂工艺为：室温～350℃，升温时间为100分钟，保温40分钟；350℃～430~C，升温时间为60分钟，保温60分钟；最后随炉冷却到室温。
研究了不同的烧结温度与不同的保温时间对烧结密度的影响。结
果表明，随着烧结温度的升高，保温时间的延长，烧结坯的密度明显
提高。1280℃下烧结2小时，密度可达8.13眺m，。烧结采用氢气气
氛，使得烧结坯几乎完全脱碳，这对合金的膨胀系数有着积极的影响。
研制的Kovar合金的热膨胀系数达到了国家有关标准。
Kovar alloys have a lower thermal expansion coefficient .They can be sealed with materials such as ceramics, glass. And they are widely used in the fields of microelectronics and optical fiber communication. The rheological behaviors of powder feedstocks and debinding rules of
molded compact are studied on the base of capillary rheometer and TGA. The SEM and thermal expansion analysis are used to investigate the microstructures of the parts of MIM Kovar alloys and the thermal expansion properties respetively.
The feedstocks rheology of three wax-based multi-polymer binders were investigated. Through comparison of n value (exponent used to characterize the fluid ) .The feedstock suitable for MIM was abtained:58%PW+20CERESIN+10%EVA
+10%HDPE+2%SA. The according optimum MIM process parameters were also acquired: injection temperature is between 135℃ and 140 ℃ ,molding pressure is 80%,holding pressure is 70% and mold temperature is 40 ℃ .Thermal debinding technology and solvent debinding technology were both used. And thermal debinding was under the atmosphere of H2.The ideal process was divided into four stages:(1)the temperature increases from room temperature to 115℃ in 30mins;(2) the temperature increases form 115 ℃ to 350 ℃ in 240mins and then
remains for 60mins; (3) the temperature increases from 350℃to 490℃ in 30mins and then holds 30mins; (4) the temperature increases from 490 ℃ to 650℃ in 30mins and then holds 30mins.The ideal solvent debinding process in that the injection compact is dipped into the mixture of trichlene+ethanol+peanut oil to do debinding for 13 hours. Then the following thermal debinding process is needed: the temperature increases from 350 ℃ to 430 ℃ in 60mins and then holds 60mins;thus the debinding compact cools to room temperature with the oven.
The different sintering temperatures and holding times on sintered compact density were also studied. The results show that the sintered compact density was obvious improved with the increase of sintering temperature and holding time. The compacts were sintered at the temperature of 1280℃ for two hours and their densities were increased to 8.13g/cm3.Sintered under the atmosphere of H2,the carbon in the sintered compact was almost eliminated. This has a positive effect on the expansion coefficient of alloys.
The thermal expansion coefficients of Kovar alloys meet the requirement of GB.
引文
[1] Cremer, MIM, a new processs for part corfiglaration, EPMA, 1989
[2] R M German著．曲选辉等译 粉末注射成形，长沙：中南大学出版社，2001
[3] L.F. Pease, A Perspective on the Markets and Technology for Injection Molded Metal Powder and Ceramic Parts. International Journal of Powder Metallurgy, 1986, vol. 22,177～187
[4] A. Hauck, Powder Injection Molding Current And Long Term Outlook: The International Journal of Powder Metallurgy, 2000, 36 (3): 29～36
[5] R.M. German, The Scientific Status of Metal Powder Injection Molding: The International Journal of Powder Metallurgy, 2000, 36 (3): 31～36
[6] Andew D. Hanson and Steven C. Perruzza, Optimizing Component Designs For Metal Injection Molding: The International Journal of Powder Metallurgy, 2000, 36 (3): 37～42
[7] 李益民，黄伯云，曲选辉．当代金属注射成形技术 粉末冶金工业，2000，10(1)：14～19
[8] MIM Industry finds firm foodhold in japan, MPR July/August 2001
[9] Wear Applications Offer Further Growth For PIM, MPR 1999 June 24～28
[10] R.M. German. Powder Injection Molding, American Metal, Powder Industries Ferderation, Princeton, New Jersey, 1990
[11] 李松林，李益民，曲选辉，黄伯云．金属注射成形尺寸精度的影响因素及其控制 粉末冶金工业 1998，8(5)7～12
[12] K. Roy, D.D. Upadhyaya, R. K. Fotedar. Metal Injection Molding of Coarse Iron Powders. PIM 1992, 24(2) 88～90
[13] H. Zhang etal. Procesing and the mechanical properties of injection molded Fe-2Ni steels. Advances in Powder Metal, 1990, 3: 437～453
[14] German, R.M.; Hens, K.F.; Lee, D. Some variances on the sintered properties of injection molded Fe-2%Ni. Proceedings of the 1990 Powder Metallurgy Conference and Exhibition Part 3 (of 3) May 20-23 1990 1990 Publ by Metal Powder Industries Federation p 423-435 In English
[15] BASF Continues to Evolve Carbonyl Iron Powders, MRP 1999 March 18～20
[16] 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1997，12(1)61～65
[17] Rhee, B.O.; Cao, M.Y.; Zhang, H.R.; Streicher, E.; Chung, C.I. Improved wax-based binder formulations for powder injection molding. Advances in Powder Metallurgy v 2 Jun 9-12 1991 1991 Sponsored
版社，2000
[39] 姚德超主编，粉末冶金实验技术 北京：冶金工业出版社，1990
[40] 李松林，黄伯云，曲选辉，李益民．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)：131～134
[41] 李益民，曲选辉，颜寒松等 金属注射成形石蜡基粘结剂体系的性质 中南工业大学学报 1998，29(1)
[42] I.I. Rubin ed.. Handbook of plastic material and technology, Joho wiley & sonsinc, NewYork, 1990:1594
[43] M.Y. Cao, B,O, Rhee, C.I. Chang, Advance in powder metallurgy. Vol, 2 MPIF, Princeton, NJ, 1991:59
[44] M.J. Rosner, X. Zheng, M. koji, Metal powder injection molding symposium, MPIF, Princeton, NY, 1992:451
[45] E,B, Bagley, Journal of applied physics, 28(5), 1957:624
[46] 李益民，曲选辉，黄伯云，曾舟山，朱磊．多聚合物组元石蜡基MIM粘结剂分步快速脱脂过程 稀有金属材料与工程，2000，29(1)：46～49
[47] 李松林，李益民，曲选辉等 Fe-2Ni粉末注射成形溶剂脱脂相关问题的研究 材料科学与工程 2001，9(1)19～22
[48] 国家标准GBn102-81
[49] 张建，黄伯云，李益民等 烧结气氛对注射成形Fe-2Ni合金性能的影响粉末冶金材料科学与工程 1999，4(4)：316～321
[50] 虞觉奇，易文质，陈邦迪，陈宏鉴编译 二元合金状态图集 上海科学技术出版社，1984
[51] Zhang, H.; German, R.M. Structural development during sintering of injection molded Fe-2Ni steel. Advances in Powder Metallurgy v 2 Jun 9-12 1991 1991 Sponsored by: Metal Powder Industries Federation; American Powder Metallurgy Inst Publ by Metal Powder Industries Federation p 181-193 1042-8860 In English
[52] 张新富 封接合金脱碳工艺的研究 真空电子技术 2000，第3期 51～55
[2] R M German著．曲选辉等译 粉末注射成形，长沙：中南大学出版社，2001
[3] L.F. Pease, A Perspective on the Markets and Technology for Injection Molded Metal Powder and Ceramic Parts. International Journal of Powder Metallurgy, 1986, vol. 22,177～187
[4] A. Hauck, Powder Injection Molding Current And Long Term Outlook: The International Journal of Powder Metallurgy, 2000, 36 (3): 29～36
[5] R.M. German, The Scientific Status of Metal Powder Injection Molding: The International Journal of Powder Metallurgy, 2000, 36 (3): 31～36
[6] Andew D. Hanson and Steven C. Perruzza, Optimizing Component Designs For Metal Injection Molding: The International Journal of Powder Metallurgy, 2000, 36 (3): 37～42
[7] 李益民，黄伯云，曲选辉．当代金属注射成形技术 粉末冶金工业，2000，10(1)：14～19
[8] MIM Industry finds firm foodhold in japan, MPR July/August 2001
[9] Wear Applications Offer Further Growth For PIM, MPR 1999 June 24～28
[10] R.M. German. Powder Injection Molding, American Metal, Powder Industries Ferderation, Princeton, New Jersey, 1990
[11] 李松林，李益民，曲选辉，黄伯云．金属注射成形尺寸精度的影响因素及其控制 粉末冶金工业 1998，8(5)7～12
[12] K. Roy, D.D. Upadhyaya, R. K. Fotedar. Metal Injection Molding of Coarse Iron Powders. PIM 1992, 24(2) 88～90
[13] H. Zhang etal. Procesing and the mechanical properties of injection molded Fe-2Ni steels. Advances in Powder Metal, 1990, 3: 437～453
[14] German, R.M.; Hens, K.F.; Lee, D. Some variances on the sintered properties of injection molded Fe-2%Ni. Proceedings of the 1990 Powder Metallurgy Conference and Exhibition Part 3 (of 3) May 20-23 1990 1990 Publ by Metal Powder Industries Federation p 423-435 In English
[15] BASF Continues to Evolve Carbonyl Iron Powders, MRP 1999 March 18～20
[16] 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1997，12(1)61～65
[17] Rhee, B.O.; Cao, M.Y.; Zhang, H.R.; Streicher, E.; Chung, C.I. Improved wax-based binder formulations for powder injection molding. Advances in Powder Metallurgy v 2 Jun 9-12 1991 1991 Sponsored
版社，2000
[39] 姚德超主编，粉末冶金实验技术 北京：冶金工业出版社，1990
[40] 李松林，黄伯云，曲选辉，李益民．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)：131～134
[41] 李益民，曲选辉，颜寒松等 金属注射成形石蜡基粘结剂体系的性质 中南工业大学学报 1998，29(1)
[42] I.I. Rubin ed.. Handbook of plastic material and technology, Joho wiley & sonsinc, NewYork, 1990:1594
[43] M.Y. Cao, B,O, Rhee, C.I. Chang, Advance in powder metallurgy. Vol, 2 MPIF, Princeton, NJ, 1991:59
[44] M.J. Rosner, X. Zheng, M. koji, Metal powder injection molding symposium, MPIF, Princeton, NY, 1992:451
[45] E,B, Bagley, Journal of applied physics, 28(5), 1957:624
[46] 李益民，曲选辉，黄伯云，曾舟山，朱磊．多聚合物组元石蜡基MIM粘结剂分步快速脱脂过程 稀有金属材料与工程，2000，29(1)：46～49
[47] 李松林，李益民，曲选辉等 Fe-2Ni粉末注射成形溶剂脱脂相关问题的研究 材料科学与工程 2001，9(1)19～22
[48] 国家标准GBn102-81
[49] 张建，黄伯云，李益民等 烧结气氛对注射成形Fe-2Ni合金性能的影响粉末冶金材料科学与工程 1999，4(4)：316～321
[50] 虞觉奇，易文质，陈邦迪，陈宏鉴编译 二元合金状态图集 上海科学技术出版社，1984
[51] Zhang, H.; German, R.M. Structural development during sintering of injection molded Fe-2Ni steel. Advances in Powder Metallurgy v 2 Jun 9-12 1991 1991 Sponsored by: Metal Powder Industries Federation; American Powder Metallurgy Inst Publ by Metal Powder Industries Federation p 181-193 1042-8860 In English
[52] 张新富 封接合金脱碳工艺的研究 真空电子技术 2000，第3期 51～55