轿车底盘铝合金后副车架的高真空压铸技术开发与研究
|
摘要
基于低碳经济及汽车行业的竞争日趋激烈,轿车轻量化技术是汽车工业可持续发展的必然方向。其中汽车底盘悬架关键零部件的轻量化及其成形技术是当前国内外重点开发的前沿领域之一。为配合广汽集团国产自主品牌轿车的开发,本文针对该车中的底盘后副车架零件,首次在国内研发了具有自主知识产权的轿车底盘后副车架用高强韧压铸铝合金及其高真空压铸成形技术,满足了自主品牌轿车的开发需求。本课题对于提升我国汽车零部件的制造技术水平,特别是压铸工业的技术水平,促进我国汽车行业的发展,有着非常重要的理论和实际意义。
本文设计并优化了铝合金后副车架的高真空压铸工艺。采用FLOW-3D数值模拟软件分析了铝合金后副车架在不同工艺下的压铸充型过程,优化出了合理的浇注系统及排气/溢流系统。设计并制作了高真空压铸用模具密封结构,在使用自主研发的高真空压铸控制系统及真空截止阀时,模具型腔的真空度可在1s内达到91kPa以上。以Al-Mg合金为基础,研究了Mg、Si、Mg /Si比值、Ti、Cu、Be等微量元素对后副车架随铸试样力学性能的影响,获得了适用于后副车架高真空压铸技术的新型高强韧压铸铝合金,其化学成分约为Mg 5.6%,Si 1.78%,Cu 0.0142%,Ti 0.182%,Be 0.0035%。
研究了高真空压射工艺参数如模具型腔真空度、抽真空时间、压射速度及高速切换点位置等对铸件内部质量及力学性能的影响。试验结果表明:该铝合金轿车底盘后副车架在最佳高真空压铸工艺参数:抽真空启动/停止位置分别为110mm和700mm;冲头慢压射速度0.19m/s,快压射速度5.8m/s;高速切换点240mm;型腔真空度91kPa以上时,铸件外观成形良好,组织致密,无缩孔气孔缺陷。铸件本体抗拉强度达240MPa以上、屈服强度达145MPa以上、延伸率达6%以上。
最后针对后副车架压铸生产中常出现的典型缺陷如冷隔、裂纹、气孔、缩孔、粘模拉伤等,分析了它们的特征、形成机理、影响因素,并提出了防止措施和解决方案,取得了良好的效果。
Based on low carbon economy and automotive increasingly fierce competition, Car lightweight technology is the inevitable direction of sustainable development in automotive industry. The development of lightweight and forming technique for car chassis suspension key parts is one of the foremost field at home and abroad today. To cater for the development of homebred own-brand cars for Guangzhou automobile group, innovative die casting aluminium alloy which is high strength and ductility, and high vacuum die-casting forming technology for the rear sub-frame of car chassis is researched and developed for the first time in domestic in this paper, which meet the development requirements for own-brand cars. This research will have significant iMPacts in theoretical and practical on automotive parts manufacturing technology level, especially on die-casting industrial technology level, and promote the development of automobile in China.
The high vacuum die-casting technology for aluminium alloy rear sub-frame is designed and optimized in this paper. Die-casting filling process in different techniques is simulated with FLOW-3D numerical simulation software, and optimized a reasonable pouring and overflowing system. The mould sealing structure for high vacuum die-casting is desinged and manufactured, which can make the vacuum level of cavity being up to 91 kPa in a second through the use of an innovative high vacuum control system and vacuum stop valve.
Based on Al-Mg alloy, the effects of composition including magnesium, silicon, the ratio of magnesium and silicon, titanium, beryllium copper on casting mechanical properties were investigated in this paper. A new die casting aluminium alloy with high strength and ductility is developed for the rear sub-frame high vacuum die casting, the composition of which is about Mg 5.6%, Si 1.78%, Cu 0.0142%, Ti 0.182%, Be 0.0035%.
Effects of shot parameters including vacuum level, venting time, shot velocity and switch position of fast velocity on casting quality and mechanical properties were investigated for the high vacuum die-cast car chassis part in this paper. The results showed that the vacuumed startup and stop position are 110mm and 700mm respectively, and the vacuum level of cavity is up to 91 kPa. Meanwhile the slow and fast velocity of the injection punch are 0.19 and 5.8 m/s, and switch position of fast velocity is 240mm. The round car chassis part can be achieved under above parameters, whose tensile strength is over 240 MPa, yield strength over 145 MPa and elongation up to 6%.
At the end of the paper, the characteristics, formation mechanisms and influencing factors of high vacuum die casing defects during the process of production of rear sub-frame were analyzed, which included cold lap, cracks, porosity, shrinkage, etc. and prevent measures and solutions were proposed.
本文设计并优化了铝合金后副车架的高真空压铸工艺。采用FLOW-3D数值模拟软件分析了铝合金后副车架在不同工艺下的压铸充型过程,优化出了合理的浇注系统及排气/溢流系统。设计并制作了高真空压铸用模具密封结构,在使用自主研发的高真空压铸控制系统及真空截止阀时,模具型腔的真空度可在1s内达到91kPa以上。以Al-Mg合金为基础,研究了Mg、Si、Mg /Si比值、Ti、Cu、Be等微量元素对后副车架随铸试样力学性能的影响,获得了适用于后副车架高真空压铸技术的新型高强韧压铸铝合金,其化学成分约为Mg 5.6%,Si 1.78%,Cu 0.0142%,Ti 0.182%,Be 0.0035%。
研究了高真空压射工艺参数如模具型腔真空度、抽真空时间、压射速度及高速切换点位置等对铸件内部质量及力学性能的影响。试验结果表明:该铝合金轿车底盘后副车架在最佳高真空压铸工艺参数:抽真空启动/停止位置分别为110mm和700mm;冲头慢压射速度0.19m/s,快压射速度5.8m/s;高速切换点240mm;型腔真空度91kPa以上时,铸件外观成形良好,组织致密,无缩孔气孔缺陷。铸件本体抗拉强度达240MPa以上、屈服强度达145MPa以上、延伸率达6%以上。
最后针对后副车架压铸生产中常出现的典型缺陷如冷隔、裂纹、气孔、缩孔、粘模拉伤等,分析了它们的特征、形成机理、影响因素,并提出了防止措施和解决方案,取得了良好的效果。
Based on low carbon economy and automotive increasingly fierce competition, Car lightweight technology is the inevitable direction of sustainable development in automotive industry. The development of lightweight and forming technique for car chassis suspension key parts is one of the foremost field at home and abroad today. To cater for the development of homebred own-brand cars for Guangzhou automobile group, innovative die casting aluminium alloy which is high strength and ductility, and high vacuum die-casting forming technology for the rear sub-frame of car chassis is researched and developed for the first time in domestic in this paper, which meet the development requirements for own-brand cars. This research will have significant iMPacts in theoretical and practical on automotive parts manufacturing technology level, especially on die-casting industrial technology level, and promote the development of automobile in China.
The high vacuum die-casting technology for aluminium alloy rear sub-frame is designed and optimized in this paper. Die-casting filling process in different techniques is simulated with FLOW-3D numerical simulation software, and optimized a reasonable pouring and overflowing system. The mould sealing structure for high vacuum die-casting is desinged and manufactured, which can make the vacuum level of cavity being up to 91 kPa in a second through the use of an innovative high vacuum control system and vacuum stop valve.
Based on Al-Mg alloy, the effects of composition including magnesium, silicon, the ratio of magnesium and silicon, titanium, beryllium copper on casting mechanical properties were investigated in this paper. A new die casting aluminium alloy with high strength and ductility is developed for the rear sub-frame high vacuum die casting, the composition of which is about Mg 5.6%, Si 1.78%, Cu 0.0142%, Ti 0.182%, Be 0.0035%.
Effects of shot parameters including vacuum level, venting time, shot velocity and switch position of fast velocity on casting quality and mechanical properties were investigated for the high vacuum die-cast car chassis part in this paper. The results showed that the vacuumed startup and stop position are 110mm and 700mm respectively, and the vacuum level of cavity is up to 91 kPa. Meanwhile the slow and fast velocity of the injection punch are 0.19 and 5.8 m/s, and switch position of fast velocity is 240mm. The round car chassis part can be achieved under above parameters, whose tensile strength is over 240 MPa, yield strength over 145 MPa and elongation up to 6%.
At the end of the paper, the characteristics, formation mechanisms and influencing factors of high vacuum die casing defects during the process of production of rear sub-frame were analyzed, which included cold lap, cracks, porosity, shrinkage, etc. and prevent measures and solutions were proposed.
引文
[1]海老泽赐寿雄.ダイカスト技術の最新情報[J] .铸造工学(日),2003,75(6):422~ 427
[2]周健波,田福祥.我国压力铸造技术的现状与发展[J].电加工与模具,2006年增刊:17~21
[3] Komazaki Toru. MIG welding characteristics of aluminium vacuum die castings[J]. Japan Foundry Engineering Society,2004,76(4):289~295
[4] Wolfgang S. Heat treatment of aluminium casting alloys for vacuum die casting[J]. Light Metal Age,1998,(10):12~37
[5]万里,潘欢,罗吉荣.高真空压铸技术及高强韧压铸铝合金开发和应用的现状及前景[J].特种铸造及有色合金,2007,27(12):939~942
[6] Park,J.Y. Kim,E.S. Park,I.M. et al. Development of Al-15%Si hypereutectic alloy automotive part by local squeeze and vacuum die-casting[J]. Diffus Def Data Pt B. 2006:110~113
[7] E.S. Lim,K.W. Lee,K.H. Characterization of Partial Squeeze and Vacuum Die Casting Process in Fabricating Automobile Parts[C]. Kim, Strategic Technology, The 1st International Forum on. 18~20 Oct.,2006:433~437
[8] Kim, E.S. Feasibility study of the partial squeeze and vacuum die casting process[J]. Materials Processing Technology,2000,105(1):42~48
[9] J.Wannasin,R.canyook,R.Burapa et al. Evaluation of solid fraction in a rheocast aluminium die casting alloy by a rapid quenching method[J]. Scripta Materialia59,2008:1091~1094
[10]彭靓,孙文德,钱翰城.压铸铝合金及先进的压铸技术[J].铸造,2001,50(1):14~16
[11]潘欢.铝合金压铸用高真空技术的开发与应用[D].武汉:华中科技大学,2008
[12]何伟.高真空压铸用高真空控制技术的开发与应用[D].武汉:华中科技大学,2009
[13]近藤和利,青山俊三,酒井信行等.自動車ピラーテスト型を用いての高真空ダイカスト技術で得られる品質特性の検証[C].2002日本ダイカスト会議論文集,日本横滨:日本ダイカスト学会,2002
[14]トヨタ自動車(株).軽量·高品質なアルミニウム製サスペンションメンバ[J].素形材,2005,46(1):3
[15]リーョビ(株).溶接可能な薄肉高品位ダイカスト[J].素形材,2005,46(1):7
[16]胡泊,熊守美,村上正幸等.真空压铸中型腔真空压力的理论计算及试验研究[J].铸造,2007,(03):258~261
[17]古云旺,李俊贤.一种压铸机之真空阀结构[P].中国,实用新型专利,97250482.6,1998
[18]征界自动化机械股份有限公司.压铸机的真空阀[P].中国,实用新型专利,02201383.0,2002
[19]杜柳青,余永维,罗辑等.基于LOGO!的压铸模具真空装置控制系统设计[J].制造技术与机床,2007,(03):81~83
[20]万里,林海,何伟等.压铸用高真空控制系统的开发与应用[J].特种铸造及有色合金,2010,30(7):633~635
[21]唐玉林.从世界压铸工业及市场发展看中国的压铸工业[C].第四届中国国际压铸会议论文集.北京:机械工业出版社,2004.1~10
[22] Sakamoto Tetsuo,Kira Keiji,Kambe Hiroshi. Development of automotive suspension part by high vacuum die casting[J]. Japan Foundry Engineering Society,2004,76(4):283~288
[23]赖华清.压铸工艺及模具[M].机械工业出版社,2004.161~172
[24]潘宪曾,张化明,荆玉春.压铸工艺与模具[M].电子工业出版社,2006.123~132
[25]许洪斌,陈元芳.压铸成形工艺及模具[M].化学工业出版社,2008.143~157
[26]赵浩峰.现代压力铸造技术[M].中国标准出版社,2003.196~212
[27]杨裕国.铝压铸成型及质量控制[M].北京:化学工业出版社,2009.89~95
[28]吴春苗.压铸技术手册(第二册)[M].广东科技出版社,2007.313~317
[29]华隆政.压铸模设计中排气问题的探讨[J].特种铸造及有色合金,2001中国压铸、挤压铸造、半固态加工学术年会论文集. 2001:35~36
[30] Meyerson G,Rackner B.CVAPDC. Software Package Calculates Vent Area for Vacuum Die Casting[J]. Die Casting Engineer,1994,38(1):30~22
[31]赵芸芸,万里,潘欢.一种高真空压铸用压铸模的密封结构[P].中国,实用新型专利,200720085341.9,2007
[32] Nahe A. EI-Mahallawy,Mohamed A.Taha,Engenius Pokora et al. The influence of process variables on the thermal conditions and properties of high pressure die-cast magnesium alloys[J]. Materials processing technology,1998(73):125~138
[33]彭继慎,宋绍楼,单明等.压铸机控制技术[M].机械工业出版社,2006.46~76
[34]唐剑,王德满,刘静安等.铝合金熔炼与铸造技术[M].冶金工业出版社,2008.101~112
[35]万里,林海,何伟等.压铸用高真空控制系统的开发与应用[J].特种铸造及有色合金,2009年压铸专刊:156~159
[36] S.M.Lee,P.K.Seo,C.G.Kang. Effect of injection velocity on structure part characteristic in AZ50 die casting process with high vacuum system[J]. Mater.Sci.Technol.,vol.24,no.1,2008:75~79
[37] Sadayappan,K.Characterization of magnesium automotive components produced by super-vacuum die casting process[C]. Materials Science Forum,2009. 381~386
[38]万里.特种铸造工学基础[M].化学工业出版社,2009.61~64
[39]陈国策.抽真空截止点的位置对压铸件的气孔影响[J].特种铸造及有色合金,2002年压铸专刊:78~79
[40]丁惠麟,辛智华.实用铝、铜及其合金金相热处理和失效分析[M].机械工业出版社,2008.231~236
[41]龚磊清,金长庚,刘发信等.铸造铝合金金相图谱[M].长沙:中南大学出版社,1987.147~154
[42]司乃潮,傅明喜.有色金属材料及制备[M].北京:化学工业出版社,2006.87~92
[43] Gao Deming,Zhang Yuhui,Hua Qin et al. Study on mechnical properties of Mg-Al-Zn-Mn alloys cast by tow different methods[J]. Materials Science and Engieering A507(2009):1~5
[44]宋鸿武.Al-Cu合金压铸工艺研究[J].铸造技术,2006,(1):16~19
[45] H.Mayer,M.Papakyriacou,B.Zettl et al. Influence of porosity on the fatigue limit of die cast magnesium and aluminium[J]. International Journal of Fatigue 25,2003:245~256
[46] Akira Ueno,Susumu Miyakawa,Koji Yamada et al. Fatigue behavior of die casting aluminium alloys in air and vacuum[J]. Procedia Engineering 2,2010:1937~1943
[47]齐丕骧,齐霖.铝合金挤压铸件缺陷概论[J].特种铸造及有色合金,2001中国压铸、挤压铸造、半固态加工学术年会论文集,2001:104~107
[48] X.P. Niu. Chair Vacuum assisted high pressure die casting of aluminium alloys. Elsevier Science S.A.2000
[49]廖慧敏,龙思远,石光华.压铸镁合金方向盘裂纹的分析及防止[J].铸造,2008,9:974~977
[2]周健波,田福祥.我国压力铸造技术的现状与发展[J].电加工与模具,2006年增刊:17~21
[3] Komazaki Toru. MIG welding characteristics of aluminium vacuum die castings[J]. Japan Foundry Engineering Society,2004,76(4):289~295
[4] Wolfgang S. Heat treatment of aluminium casting alloys for vacuum die casting[J]. Light Metal Age,1998,(10):12~37
[5]万里,潘欢,罗吉荣.高真空压铸技术及高强韧压铸铝合金开发和应用的现状及前景[J].特种铸造及有色合金,2007,27(12):939~942
[6] Park,J.Y. Kim,E.S. Park,I.M. et al. Development of Al-15%Si hypereutectic alloy automotive part by local squeeze and vacuum die-casting[J]. Diffus Def Data Pt B. 2006:110~113
[7] E.S. Lim,K.W. Lee,K.H. Characterization of Partial Squeeze and Vacuum Die Casting Process in Fabricating Automobile Parts[C]. Kim, Strategic Technology, The 1st International Forum on. 18~20 Oct.,2006:433~437
[8] Kim, E.S. Feasibility study of the partial squeeze and vacuum die casting process[J]. Materials Processing Technology,2000,105(1):42~48
[9] J.Wannasin,R.canyook,R.Burapa et al. Evaluation of solid fraction in a rheocast aluminium die casting alloy by a rapid quenching method[J]. Scripta Materialia59,2008:1091~1094
[10]彭靓,孙文德,钱翰城.压铸铝合金及先进的压铸技术[J].铸造,2001,50(1):14~16
[11]潘欢.铝合金压铸用高真空技术的开发与应用[D].武汉:华中科技大学,2008
[12]何伟.高真空压铸用高真空控制技术的开发与应用[D].武汉:华中科技大学,2009
[13]近藤和利,青山俊三,酒井信行等.自動車ピラーテスト型を用いての高真空ダイカスト技術で得られる品質特性の検証[C].2002日本ダイカスト会議論文集,日本横滨:日本ダイカスト学会,2002
[14]トヨタ自動車(株).軽量·高品質なアルミニウム製サスペンションメンバ[J].素形材,2005,46(1):3
[15]リーョビ(株).溶接可能な薄肉高品位ダイカスト[J].素形材,2005,46(1):7
[16]胡泊,熊守美,村上正幸等.真空压铸中型腔真空压力的理论计算及试验研究[J].铸造,2007,(03):258~261
[17]古云旺,李俊贤.一种压铸机之真空阀结构[P].中国,实用新型专利,97250482.6,1998
[18]征界自动化机械股份有限公司.压铸机的真空阀[P].中国,实用新型专利,02201383.0,2002
[19]杜柳青,余永维,罗辑等.基于LOGO!的压铸模具真空装置控制系统设计[J].制造技术与机床,2007,(03):81~83
[20]万里,林海,何伟等.压铸用高真空控制系统的开发与应用[J].特种铸造及有色合金,2010,30(7):633~635
[21]唐玉林.从世界压铸工业及市场发展看中国的压铸工业[C].第四届中国国际压铸会议论文集.北京:机械工业出版社,2004.1~10
[22] Sakamoto Tetsuo,Kira Keiji,Kambe Hiroshi. Development of automotive suspension part by high vacuum die casting[J]. Japan Foundry Engineering Society,2004,76(4):283~288
[23]赖华清.压铸工艺及模具[M].机械工业出版社,2004.161~172
[24]潘宪曾,张化明,荆玉春.压铸工艺与模具[M].电子工业出版社,2006.123~132
[25]许洪斌,陈元芳.压铸成形工艺及模具[M].化学工业出版社,2008.143~157
[26]赵浩峰.现代压力铸造技术[M].中国标准出版社,2003.196~212
[27]杨裕国.铝压铸成型及质量控制[M].北京:化学工业出版社,2009.89~95
[28]吴春苗.压铸技术手册(第二册)[M].广东科技出版社,2007.313~317
[29]华隆政.压铸模设计中排气问题的探讨[J].特种铸造及有色合金,2001中国压铸、挤压铸造、半固态加工学术年会论文集. 2001:35~36
[30] Meyerson G,Rackner B.CVAPDC. Software Package Calculates Vent Area for Vacuum Die Casting[J]. Die Casting Engineer,1994,38(1):30~22
[31]赵芸芸,万里,潘欢.一种高真空压铸用压铸模的密封结构[P].中国,实用新型专利,200720085341.9,2007
[32] Nahe A. EI-Mahallawy,Mohamed A.Taha,Engenius Pokora et al. The influence of process variables on the thermal conditions and properties of high pressure die-cast magnesium alloys[J]. Materials processing technology,1998(73):125~138
[33]彭继慎,宋绍楼,单明等.压铸机控制技术[M].机械工业出版社,2006.46~76
[34]唐剑,王德满,刘静安等.铝合金熔炼与铸造技术[M].冶金工业出版社,2008.101~112
[35]万里,林海,何伟等.压铸用高真空控制系统的开发与应用[J].特种铸造及有色合金,2009年压铸专刊:156~159
[36] S.M.Lee,P.K.Seo,C.G.Kang. Effect of injection velocity on structure part characteristic in AZ50 die casting process with high vacuum system[J]. Mater.Sci.Technol.,vol.24,no.1,2008:75~79
[37] Sadayappan,K.Characterization of magnesium automotive components produced by super-vacuum die casting process[C]. Materials Science Forum,2009. 381~386
[38]万里.特种铸造工学基础[M].化学工业出版社,2009.61~64
[39]陈国策.抽真空截止点的位置对压铸件的气孔影响[J].特种铸造及有色合金,2002年压铸专刊:78~79
[40]丁惠麟,辛智华.实用铝、铜及其合金金相热处理和失效分析[M].机械工业出版社,2008.231~236
[41]龚磊清,金长庚,刘发信等.铸造铝合金金相图谱[M].长沙:中南大学出版社,1987.147~154
[42]司乃潮,傅明喜.有色金属材料及制备[M].北京:化学工业出版社,2006.87~92
[43] Gao Deming,Zhang Yuhui,Hua Qin et al. Study on mechnical properties of Mg-Al-Zn-Mn alloys cast by tow different methods[J]. Materials Science and Engieering A507(2009):1~5
[44]宋鸿武.Al-Cu合金压铸工艺研究[J].铸造技术,2006,(1):16~19
[45] H.Mayer,M.Papakyriacou,B.Zettl et al. Influence of porosity on the fatigue limit of die cast magnesium and aluminium[J]. International Journal of Fatigue 25,2003:245~256
[46] Akira Ueno,Susumu Miyakawa,Koji Yamada et al. Fatigue behavior of die casting aluminium alloys in air and vacuum[J]. Procedia Engineering 2,2010:1937~1943
[47]齐丕骧,齐霖.铝合金挤压铸件缺陷概论[J].特种铸造及有色合金,2001中国压铸、挤压铸造、半固态加工学术年会论文集,2001:104~107
[48] X.P. Niu. Chair Vacuum assisted high pressure die casting of aluminium alloys. Elsevier Science S.A.2000
[49]廖慧敏,龙思远,石光华.压铸镁合金方向盘裂纹的分析及防止[J].铸造,2008,9:974~977