镁合金醇基阻燃涂料的研究
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摘要
镁合金化学性质活泼,液态的镁极易和大气中的氧气、氮气及铸型中的水发生反应,结果在铸件表面出现孔洞或氧化皱皮,降低铸件表面质量,给生产企业带来很大的压力。
本文对镁合金阻燃涂料原料选择、配比、浇注效果等进行了研究。对单一主要助剂种类及加入量对涂料工艺性能的影响进行了试验与分析。重点研究了硅溶胶、聚乙烯醇缩丁醛(PVB)、酚醛树脂、凹凸棒土、耐火骨料对涂料流变性、触变性、粘度、悬浮性、密度、透气性、常温强度、高温强度及高温抗裂性的影响。研究发现硅溶胶作为粘结剂,涂料常、高温强度不高,达不到使用要求,而酚醛树脂粘结效果较好,可以代替硅溶胶。最终确定涂料的成分组成为氧化铁红70%、滑石粉20%、石英粉10%,酚醛树脂4%、凹凸棒土3%、聚乙烯醇缩丁醛(PVB)0.25%、硼酸3%、十二烷基磺酸钠0.2%。
将研制涂料与意大利阻燃涂料性能进行对比发现,研制涂料密的密度、发气量、透气性及悬浮性均高于意大利涂料,而两者的常、高温强度及高温抗裂性相差不大。研制涂料与意大利涂料的镁合金充型高度对比发现,研制涂料保温能力强,充型高度比意大利涂料高15%,更适合于镁合金的铸造生产。
在铸造车间进行了该涂料的现场浇注实验。实验结果表明:涂料阻燃性能好,涂层强度高,没有出现急热开裂和塌箱等现象;透气性良好,浇注充型平稳,未出现反喷、浇不足等现象;抗粘砂性能强;而且涂料层容易脱落。研制的涂料可满足生产实际需要。
Chemical properties of magnesium element is very active, when being liquid, it can easily react with oxygen and nitrogen of the air and water in the mold. As a result, pores and oxide skin appear on the surface of cast magnesium alloy, and the casting surface quality reduces, which had caused great pressure on manufacturers.
This paper first study the effect of silicasol, polyvinyl butyral, phenolic resin, attapulgite and fire-resistant aggregate on the physical properties that is rheology, thixotropy, viscosity, suspensibility, density, permeability, strength under ambient and high temperature, as well as the cracking resistance under high temperature. The results show that the strength of the coating with silicasol as binder agent under ambient and high temperature is too low to reach the application requirements, while that with phenolic resin as binder agent has well bonding effect and can be used as a substitute of silicasol. Then we optimize the content of the raw materials, ferric oxide 70%, talc 20%, quartz powder 10%, phenolic resin 4%, attapulgite 3%,polyvinyl butyral 0.25%, Boric Acid 3% and SDS 0.2%.
The properties of the developed flame retardant coating and the Italian coating were compared. The density, gas evolution, permeability and suspension property of the developed coating were better than that of the Italian coating, while there is no obvious difference in the strength under ambient-temperature and high-temperature and high temperature cracking resistance of the two coatings. The filling height in the casting of magnesium alloy using the developed flame retardant coating and the Italian coating as retardant coating also were compared, it was found that the filling height of developed flame retardant coating was 15 percent higher than that of the Italian coating, so the developed coating is suitable for the castings of magnesium alloy.
Casting experiments show that the developed coating has good flame retardancy and high strength; acute thermal cracking and sand crushing did not happen; the permeability was well and the pour filling was steady; the reverse ejection and missrun phenomena did not appear. Moreover, the ability of resisting sand penetration was well. The coating can be easily split away off. Therefore, the developed coating can meet the actual needs of the casting of magnesium alloy.
本文对镁合金阻燃涂料原料选择、配比、浇注效果等进行了研究。对单一主要助剂种类及加入量对涂料工艺性能的影响进行了试验与分析。重点研究了硅溶胶、聚乙烯醇缩丁醛(PVB)、酚醛树脂、凹凸棒土、耐火骨料对涂料流变性、触变性、粘度、悬浮性、密度、透气性、常温强度、高温强度及高温抗裂性的影响。研究发现硅溶胶作为粘结剂,涂料常、高温强度不高,达不到使用要求,而酚醛树脂粘结效果较好,可以代替硅溶胶。最终确定涂料的成分组成为氧化铁红70%、滑石粉20%、石英粉10%,酚醛树脂4%、凹凸棒土3%、聚乙烯醇缩丁醛(PVB)0.25%、硼酸3%、十二烷基磺酸钠0.2%。
将研制涂料与意大利阻燃涂料性能进行对比发现,研制涂料密的密度、发气量、透气性及悬浮性均高于意大利涂料,而两者的常、高温强度及高温抗裂性相差不大。研制涂料与意大利涂料的镁合金充型高度对比发现,研制涂料保温能力强,充型高度比意大利涂料高15%,更适合于镁合金的铸造生产。
在铸造车间进行了该涂料的现场浇注实验。实验结果表明:涂料阻燃性能好,涂层强度高,没有出现急热开裂和塌箱等现象;透气性良好,浇注充型平稳,未出现反喷、浇不足等现象;抗粘砂性能强;而且涂料层容易脱落。研制的涂料可满足生产实际需要。
Chemical properties of magnesium element is very active, when being liquid, it can easily react with oxygen and nitrogen of the air and water in the mold. As a result, pores and oxide skin appear on the surface of cast magnesium alloy, and the casting surface quality reduces, which had caused great pressure on manufacturers.
This paper first study the effect of silicasol, polyvinyl butyral, phenolic resin, attapulgite and fire-resistant aggregate on the physical properties that is rheology, thixotropy, viscosity, suspensibility, density, permeability, strength under ambient and high temperature, as well as the cracking resistance under high temperature. The results show that the strength of the coating with silicasol as binder agent under ambient and high temperature is too low to reach the application requirements, while that with phenolic resin as binder agent has well bonding effect and can be used as a substitute of silicasol. Then we optimize the content of the raw materials, ferric oxide 70%, talc 20%, quartz powder 10%, phenolic resin 4%, attapulgite 3%,polyvinyl butyral 0.25%, Boric Acid 3% and SDS 0.2%.
The properties of the developed flame retardant coating and the Italian coating were compared. The density, gas evolution, permeability and suspension property of the developed coating were better than that of the Italian coating, while there is no obvious difference in the strength under ambient-temperature and high-temperature and high temperature cracking resistance of the two coatings. The filling height in the casting of magnesium alloy using the developed flame retardant coating and the Italian coating as retardant coating also were compared, it was found that the filling height of developed flame retardant coating was 15 percent higher than that of the Italian coating, so the developed coating is suitable for the castings of magnesium alloy.
Casting experiments show that the developed coating has good flame retardancy and high strength; acute thermal cracking and sand crushing did not happen; the permeability was well and the pour filling was steady; the reverse ejection and missrun phenomena did not appear. Moreover, the ability of resisting sand penetration was well. The coating can be easily split away off. Therefore, the developed coating can meet the actual needs of the casting of magnesium alloy.
引文
1 K. V. Mahendra. Castable Composites and their Application in Automobiles. Proceedings of the Institution of Mechanical Engineers. 2007,121(19):135-140
2 J. Palya. Updates to MIM Make Better Net-shape Parts. Design News. 2007,7(5):20
3 D. Smoek. Net Shape Breakthrough. Design News. 2007,62(4):53
4 T.Bex. Coating Chemistry Key to EPC Consistency[J]. Modern Casting. 1989,10(16):34~35
5 A.Joseph. Automotive Mg Research and Development in North America. Material Science Forum Vols. 2007,6(12):11-24
6 T.Kaneko. Automotive Applications of Magnesium Alloys[J]. Materials Science Forum. 2003,22(1):67-72
7 G. S. Cole. Issues that Influence Magnesium’s Use in the Automotive Industry[J]. Materials Science Forum. 2003,19(1):43-50
8林志埙.镁合金熔模铸造成型工艺与组织性能研究.上海交通大学硕士学位论文, 2008
9李远才.铸造涂料及应用北京:机械工业出版社, 2007
10谭香玲,肖泽辉.镁合金消失模铸造涂料的研究进展.铸造. 2007,56(2):121-124
11 H.Shroyer. Cavityless Mold and Method of Making Same.US Patent,April 15,1958.
12 Y.Sun. Investigation of Wetting and Wicking Properties of the Refractory Coating in the EPC Process. AFS Transactions. 1992,17(39):297-308
13刘子利.镁合金消失模铸造工艺的应用基础研究[D].上海:上海交通大学, 2002
14刘子利,吴国华,丁文江. AZ91镁合金负压消失模铸造充型速度的研究[J].航空材料报. 2002,22(2):12-16
15刘子利,吴国华,丁文江.镁合金负压消失模铸造充型的研究.铸造. 2002,51(4):209-213
16梁光泽.走中国特色消失模铸造之路.铸造纵横. 2005,16(5):14-17
17朱之翰,于文杰,高庆元.薄壁镁合金铸件砂型涂料的研究. China Academic Journal. 1996,6(10):30-34
18吴国华.镁合金金属型铸造涂料及制备方法.中国专利:02136198,2002.
19吴国华.镁合金消失模铸造阻燃涂料及其制备方法.中国专利:02110682,2002.
20王爱民,王开发.镁合金铸造涂料.中国专利:B22C3/00,2005.
21张云波.镁合金铸造涂料制备方法.中国专利:200710058075,2007.
22徐永东,宋运坤.稀土镁合金覆膜砂砂型铸造用涂料及其使用方法.中国专利:200810061819,2008.
23张亮.镁合金金属型铸造涂料流变性能的研究. FOUNDRY. 2009,10(58):1041-1045
24韩辉,魏兆连.对铸造涂料流变性研究的几点新认识[J].铸造技术. 1988,10(6):41-44
25胡彭生.型砂[M].上海:上海科学技术出版社, 1994
26贺奇,李焕臣,张玉成.消失模铸造水机涂料的研制[J].热加工工艺. 2005,9(6):49-50
27 B. Marehisinete. Refraetory Coatings:Making the Right Choice. Modern Casting. 1992,12(10):25-27
28 Q.Zhao. Lost Foam Coating Characterization: Heat and Mass Transfer [C]. AFS Trans. 2005,4(11):1-15
29 Y.Sun. Investigation and Properties of Refraetory Coating in the EPC Proeess. AFS Transaetions. 2003,12(5):297-308
30 A.Papo. Rheological Properties of High-build Paints Containing Castor Oil Derivations. Chem Assoc. 1980,63(12):10-14
31 C.Temple. Fundamentals of Paint Rheology Paint Technology. 1968,40(19):522
32 E.Percy. Rheolgy of Coatings. Journal of Paint Technology. 1969,40(52):533
33 G.Peter. Film Formation and Rheology of Powder Coatings. Journal of Coating Technology. 1984,56(12):717
34于华.膨润土的改性及其消失模涂料性能的研究.南京航空航天大学硕士学位论文, 2006,3
35 J.Liu. Effects of Density and Density Gradients on Metal Fill in the LFC Process AFS Transactions. 1997,139(46):435-442
36 S. Desheng. Research of Coating for Lost Foam Casting. The Forth Meeting of Nonferrous Alloys & Special Casting :Shanghai 2005,9,
37凌宏江,戴绪骑.根据铸型急热膨胀值选择涂料耐火填料.铸造. 1996,2(10):6-8
38 D. M.Dixon. Additives for Water-based Coatings. Materials Science Forum. 1990,10(6):49-59
39冯胜山,朱松林.新型醇基铸造涂料复合分散悬浮剂及其作用机理的研究.中国铸造活动周论文集. 2003,40(23):304-307
40陈敏,周联山.凹凸棒粘土在铸造涂料中的应用.铸造工程造型材料. 2001,10(5):8-9
41刘兰俊,周杰.涂料组分对消失模铸造涂料性能的影响.造型材料. 2003,6(3):8-10
42 F.W.Pursall. Coating-Past,Present and Future. The British Foundryman. 1982,75(3):10-15
43王忠柯,佟天夫.气化模铸造涂料的流变性[J].特种铸造及有色合金. 1995,4(13):5-7
44刘震伟,唐建新.不同耐火填料对消失模铸造涂料性能的影响.铸造. 2008,57(12):1294-1296
45 C.A.Gorla. Coating Permeability:A Critical Parameter of the Evaporative Pattern Process[J]. AFS Trans. 1986,10(101):589-600
46孙万柏,程宽中,高振嵩.骨料组成对消失模铸造涂料透气性的影响及测定[J].铸造. 1996,10(4):43-45
47蔡震升、戎豫.实用铸造耐火涂料.北京:冶金工业出版社, 1994
48 O.A.Martinez. A Supplier'S Overview of Lost Foam Refractory Coatings. AFS Transactions. 1990,124(67):241～244
49黄光胜.温度对消失模铸造涂料透气性的影响.铸造. 2000,49(5):276-281
50 J. Green. Formation of Surface Defects in Gray Iron Lost Foam Castings. AFS Transactions. 1998,98(111):339-347
51 C.Wang. Processing Variable Significance on Filling Thin Plates in the LFC Process. AFS Transactions [J] 1997,138(10):427-434
52 M. H.Warner. Pattern Pyrolysis Defect Reduction in Lost Foam Casting. AFS Transactions. 1998,161(140):777-785
53 P.Kurnar. Effect of Process Variables on Surface Finish and Soundness of Al-11%Si Alloy V-process Castings. AFS Transactions. 1996,159(13):1143-1150.
2 J. Palya. Updates to MIM Make Better Net-shape Parts. Design News. 2007,7(5):20
3 D. Smoek. Net Shape Breakthrough. Design News. 2007,62(4):53
4 T.Bex. Coating Chemistry Key to EPC Consistency[J]. Modern Casting. 1989,10(16):34~35
5 A.Joseph. Automotive Mg Research and Development in North America. Material Science Forum Vols. 2007,6(12):11-24
6 T.Kaneko. Automotive Applications of Magnesium Alloys[J]. Materials Science Forum. 2003,22(1):67-72
7 G. S. Cole. Issues that Influence Magnesium’s Use in the Automotive Industry[J]. Materials Science Forum. 2003,19(1):43-50
8林志埙.镁合金熔模铸造成型工艺与组织性能研究.上海交通大学硕士学位论文, 2008
9李远才.铸造涂料及应用北京:机械工业出版社, 2007
10谭香玲,肖泽辉.镁合金消失模铸造涂料的研究进展.铸造. 2007,56(2):121-124
11 H.Shroyer. Cavityless Mold and Method of Making Same.US Patent,April 15,1958.
12 Y.Sun. Investigation of Wetting and Wicking Properties of the Refractory Coating in the EPC Process. AFS Transactions. 1992,17(39):297-308
13刘子利.镁合金消失模铸造工艺的应用基础研究[D].上海:上海交通大学, 2002
14刘子利,吴国华,丁文江. AZ91镁合金负压消失模铸造充型速度的研究[J].航空材料报. 2002,22(2):12-16
15刘子利,吴国华,丁文江.镁合金负压消失模铸造充型的研究.铸造. 2002,51(4):209-213
16梁光泽.走中国特色消失模铸造之路.铸造纵横. 2005,16(5):14-17
17朱之翰,于文杰,高庆元.薄壁镁合金铸件砂型涂料的研究. China Academic Journal. 1996,6(10):30-34
18吴国华.镁合金金属型铸造涂料及制备方法.中国专利:02136198,2002.
19吴国华.镁合金消失模铸造阻燃涂料及其制备方法.中国专利:02110682,2002.
20王爱民,王开发.镁合金铸造涂料.中国专利:B22C3/00,2005.
21张云波.镁合金铸造涂料制备方法.中国专利:200710058075,2007.
22徐永东,宋运坤.稀土镁合金覆膜砂砂型铸造用涂料及其使用方法.中国专利:200810061819,2008.
23张亮.镁合金金属型铸造涂料流变性能的研究. FOUNDRY. 2009,10(58):1041-1045
24韩辉,魏兆连.对铸造涂料流变性研究的几点新认识[J].铸造技术. 1988,10(6):41-44
25胡彭生.型砂[M].上海:上海科学技术出版社, 1994
26贺奇,李焕臣,张玉成.消失模铸造水机涂料的研制[J].热加工工艺. 2005,9(6):49-50
27 B. Marehisinete. Refraetory Coatings:Making the Right Choice. Modern Casting. 1992,12(10):25-27
28 Q.Zhao. Lost Foam Coating Characterization: Heat and Mass Transfer [C]. AFS Trans. 2005,4(11):1-15
29 Y.Sun. Investigation and Properties of Refraetory Coating in the EPC Proeess. AFS Transaetions. 2003,12(5):297-308
30 A.Papo. Rheological Properties of High-build Paints Containing Castor Oil Derivations. Chem Assoc. 1980,63(12):10-14
31 C.Temple. Fundamentals of Paint Rheology Paint Technology. 1968,40(19):522
32 E.Percy. Rheolgy of Coatings. Journal of Paint Technology. 1969,40(52):533
33 G.Peter. Film Formation and Rheology of Powder Coatings. Journal of Coating Technology. 1984,56(12):717
34于华.膨润土的改性及其消失模涂料性能的研究.南京航空航天大学硕士学位论文, 2006,3
35 J.Liu. Effects of Density and Density Gradients on Metal Fill in the LFC Process AFS Transactions. 1997,139(46):435-442
36 S. Desheng. Research of Coating for Lost Foam Casting. The Forth Meeting of Nonferrous Alloys & Special Casting :Shanghai 2005,9,
37凌宏江,戴绪骑.根据铸型急热膨胀值选择涂料耐火填料.铸造. 1996,2(10):6-8
38 D. M.Dixon. Additives for Water-based Coatings. Materials Science Forum. 1990,10(6):49-59
39冯胜山,朱松林.新型醇基铸造涂料复合分散悬浮剂及其作用机理的研究.中国铸造活动周论文集. 2003,40(23):304-307
40陈敏,周联山.凹凸棒粘土在铸造涂料中的应用.铸造工程造型材料. 2001,10(5):8-9
41刘兰俊,周杰.涂料组分对消失模铸造涂料性能的影响.造型材料. 2003,6(3):8-10
42 F.W.Pursall. Coating-Past,Present and Future. The British Foundryman. 1982,75(3):10-15
43王忠柯,佟天夫.气化模铸造涂料的流变性[J].特种铸造及有色合金. 1995,4(13):5-7
44刘震伟,唐建新.不同耐火填料对消失模铸造涂料性能的影响.铸造. 2008,57(12):1294-1296
45 C.A.Gorla. Coating Permeability:A Critical Parameter of the Evaporative Pattern Process[J]. AFS Trans. 1986,10(101):589-600
46孙万柏,程宽中,高振嵩.骨料组成对消失模铸造涂料透气性的影响及测定[J].铸造. 1996,10(4):43-45
47蔡震升、戎豫.实用铸造耐火涂料.北京:冶金工业出版社, 1994
48 O.A.Martinez. A Supplier'S Overview of Lost Foam Refractory Coatings. AFS Transactions. 1990,124(67):241～244
49黄光胜.温度对消失模铸造涂料透气性的影响.铸造. 2000,49(5):276-281
50 J. Green. Formation of Surface Defects in Gray Iron Lost Foam Castings. AFS Transactions. 1998,98(111):339-347
51 C.Wang. Processing Variable Significance on Filling Thin Plates in the LFC Process. AFS Transactions [J] 1997,138(10):427-434
52 M. H.Warner. Pattern Pyrolysis Defect Reduction in Lost Foam Casting. AFS Transactions. 1998,161(140):777-785
53 P.Kurnar. Effect of Process Variables on Surface Finish and Soundness of Al-11%Si Alloy V-process Castings. AFS Transactions. 1996,159(13):1143-1150.