AZ31镁合金薄壁管材挤压成形工艺研究
|
摘要
本文以AZ31镁合金挤压薄壁管材为研究对象,讨论了模具结构、工艺参数对挤压过程的影响,并分析了挤压比对试制管材力学性能和显微组织的影响。
通过对管材不同挤压成形方法的分析,结合镁合金的热变形特点,确定选用了等温正挤压全润滑的成形方法。
应用MSC/Superform有限元模拟软件,对镁合金薄壁管材的挤压成形过程进行模拟。讨论了凹模锥角、挤压温度、挤压速度、摩擦条件及挤压比对变形中等效应力、等效应变和挤压力的影响,确定出了合理的变形工艺参数和模具结构。模拟结果显示,凹模最佳锥角为45°、挤压温度为380℃、挤压速度为0.1 mm/s和摩擦系数为0.1的条件下具有较小挤压力、合理的等效应变、等效应力分布,有利于该零件成形。
在对数值模拟结果进行分析的基础上,制订了镁合金薄壁管材的挤压成形工艺,并进行了模具设计,在模具结构设计方面着重考虑了壁厚差的控制问题。
在以上研究工作的基础上,对AZ31镁合金挤压薄壁管材进行了试制,获得了尺寸精度高、粗糙度小、壁厚差小的管材;并对组织和性能进行了测试分析,由结果可知,管材组织细密,抗拉强度和延伸率明显提高,有强的承压能力。
本文验证了数值模拟和物理实验结果的正确性以及该工艺成形镁合金薄壁管材的可行性。
The thin-wall extruded tube of magnesium alloy AZ31 is selected as research object in this paper. The influence of the structure of the mold and the process parameters on the extrusion course is discussed and influence of extrusion ratio on the mechanical properties of tube and microstructure is also analyzed.
According to analyses the different extrusion forming methods, the forming method of isothermal forward extrusion full lubrication is defined with hot deformation behaviors of magnesium alloy.
The extrusion course of thin-wall extruded tube of magnesium alloy is simulated by using the numerical simulation of finite element method (FEM). The cone angle, extrusion temperature, extruding velocity, friction conditions and extrusion ratio are discussed which impact equivalent stress, equivalent strain and extrusion force and determining the reasonable process parameters and the structure of the mold. The simulation results show that the relatively small extrusion force, reasonable distribution of equivalent strain and equivalent stress can be get when the cone angle 45°, extrusion temperature 380℃, extruding velocity 0.1 mm/s and friction coefficient 0.1, which benefit forming.
The forming process of thin-wall extruded tube of magnesium alloy is established based on analyzing the results of numerical simulation and designing mould. Emphasis is put on the control of wall thickness difference in designing the structure of the mold.
Based on above research, the tube with precise size, low roughness and little wall thickness difference is received during the trial - manufacture of the thin-wall extruded tube of magnesium alloy AZ31. Testing analyzing properties and microstructure, the result show that the tube has impact microstructure and strong bearing capability and the tensile strength and elongation improve obviously.
The correctness of numerical simulation and physics experiment and feasibility of the thin-wall extruded tube of magnesium alloy forming by this process are verified.
通过对管材不同挤压成形方法的分析,结合镁合金的热变形特点,确定选用了等温正挤压全润滑的成形方法。
应用MSC/Superform有限元模拟软件,对镁合金薄壁管材的挤压成形过程进行模拟。讨论了凹模锥角、挤压温度、挤压速度、摩擦条件及挤压比对变形中等效应力、等效应变和挤压力的影响,确定出了合理的变形工艺参数和模具结构。模拟结果显示,凹模最佳锥角为45°、挤压温度为380℃、挤压速度为0.1 mm/s和摩擦系数为0.1的条件下具有较小挤压力、合理的等效应变、等效应力分布,有利于该零件成形。
在对数值模拟结果进行分析的基础上,制订了镁合金薄壁管材的挤压成形工艺,并进行了模具设计,在模具结构设计方面着重考虑了壁厚差的控制问题。
在以上研究工作的基础上,对AZ31镁合金挤压薄壁管材进行了试制,获得了尺寸精度高、粗糙度小、壁厚差小的管材;并对组织和性能进行了测试分析,由结果可知,管材组织细密,抗拉强度和延伸率明显提高,有强的承压能力。
本文验证了数值模拟和物理实验结果的正确性以及该工艺成形镁合金薄壁管材的可行性。
The thin-wall extruded tube of magnesium alloy AZ31 is selected as research object in this paper. The influence of the structure of the mold and the process parameters on the extrusion course is discussed and influence of extrusion ratio on the mechanical properties of tube and microstructure is also analyzed.
According to analyses the different extrusion forming methods, the forming method of isothermal forward extrusion full lubrication is defined with hot deformation behaviors of magnesium alloy.
The extrusion course of thin-wall extruded tube of magnesium alloy is simulated by using the numerical simulation of finite element method (FEM). The cone angle, extrusion temperature, extruding velocity, friction conditions and extrusion ratio are discussed which impact equivalent stress, equivalent strain and extrusion force and determining the reasonable process parameters and the structure of the mold. The simulation results show that the relatively small extrusion force, reasonable distribution of equivalent strain and equivalent stress can be get when the cone angle 45°, extrusion temperature 380℃, extruding velocity 0.1 mm/s and friction coefficient 0.1, which benefit forming.
The forming process of thin-wall extruded tube of magnesium alloy is established based on analyzing the results of numerical simulation and designing mould. Emphasis is put on the control of wall thickness difference in designing the structure of the mold.
Based on above research, the tube with precise size, low roughness and little wall thickness difference is received during the trial - manufacture of the thin-wall extruded tube of magnesium alloy AZ31. Testing analyzing properties and microstructure, the result show that the tube has impact microstructure and strong bearing capability and the tensile strength and elongation improve obviously.
The correctness of numerical simulation and physics experiment and feasibility of the thin-wall extruded tube of magnesium alloy forming by this process are verified.
引文
[1]左铁镛.中国镁及镁合金发展战略[J].科学中国人,2006,(2):28-29.
[2]杜文博,吴玉锋,左铁镛.镁合金在交通工具中的应用现状[J].世界有色金属,2006,(2):19-21.
[3]周铁城.机械设计选材与强度刚度评估[J].机械工程材料.1996,(8): 40-42.
[4]张士宏,许沂,王忠堂等.镁合金成形加工技术[J].世界科技研究与发展,2002,23(6):18-21.
[5]范光尧,许沂,王忠堂等.机械成形技术与镁合金材料的应用概况[J].工业材料.2000,162(6):139-144.
[6]张青来,卢晨,丁文江.分流挤压镁合金管材工艺研究[J].轻合金加工技术,2003,31(10):28-30.
[7]曾小勤等.镁合金应用新进展[J].铸造.1998,(11):39-43.
[8]潘宪曾.镁合金在中国压铸工业中的应用——世界镁合金压铸与中国[J].铸造,2001,50(6):303～309.
[9]《轻合金材料加工手册》编写组.轻合金材料加工手册(上册)[M].北京:冶金工业出版社,1980:200～203.
[10]Winany C D. Magnesium Die-Castings in Motor Vehicles An: Smith D S. Magnesium the Lightweight Solution-Automotive Sourcing Special Report[R]. London:Automotive Sourcing UK Ltd,1998:8～9.
[11]王忠堂,张士宏,许沂等.镁合金管材挤压工艺及力能参数实验研究[J].沈阳工业学院学报,2001,20(4):66-69.
[12] Chen C C, Kobayashi S. Rigid plastic finite element analysis of ring compreesion[J]. Application of Numerical Methods to Forming Processes, ASME, AMD, 1978,V28,163.
[13] Oh S I, Rebelo N, Kobayashi S. Finte element formulation far the analysis of plastic deformation of rate-sensitive materials in metal forming[J]. Metal Forming Plasticity, Ed. By H. Lippmann, Springer Verlen, 1979,273.
[14]Li G J, Kobayashi S. Rigid plastic finite element analysis of plane strain rolling[R]. Trans. ASME, J. Eng. Ind, 1982, V104.
[15]李良福.热挤压镁合金管子的新工艺[J].铝加工,2002,25(1):20-23.
[16]张士宏,徐希,王忠堂.镁合金管件挤压工艺[J].世界科技研究与发展,2001, 23(6): 18-21.
[17]翟秋亚等.挤压变形 AZ31 镁合金组织和性能的影响[J].西安理工大学学报,2002,18(3): 254-258.
[18]汪凌云,潘复生,丁培道等.AZ31 镁合金成形性能改善研究[J].2002 年材料科学与工程进展,北京:冶金工业出版社,1980,636-640.
[19]彭大署.金属塑性加工原理[M].长沙:中南大学出版社,200.
[20]Yuanyuan Li, Datong Zhang, Feng Liu, Yan Long, and Weiping Chen. Microstructure and tensile behavior of hot extruded AZ91 alloys at room temperature[J]. Matreial Process Technology, 2002, 9(5): 352-356.
[21]Hartley Petc. Numerical Modeling of Material Deformation Process[J]. Springer-Verlag London Limited, 1992.
[22]Akihiro Yamashita, Zenji Horita, Terence G. Langdon. Improving the mechanical properties of magnesium and a magnesium alloy through severe plastic deformation[J]. Materials Science and Engineering A 300. 2001,142-147.
[23]赵新海,赵国群,王广春.金属体积成形预成形设计的现状及发展[J].塑性工程学报,2000,7(3):1-6.
[24]万胜狄.金属塑性成形原理[J].北京:机械工业出版社,1995:157.
[25]小坂田宏造,花见真司,王昕.ュンテナな驱动する锻造加工研究[C].第 5 回中日精密锻造シソポツウム论文集,1996:89-92.
[26]谢建新,刘静安.金属挤压理论与技术[M].北京:冶金工业出版社,2001:193-199.
[27]松下富春.锻造の温度,その选择意义[J].塑性と加工,1999,(40):35-40.
[28]吉村豹治,筱崎吉太郎.闭塞锻造によるネツトシュィプ锻造加工法[J].塑性と加工,2000,(10):18-21.
[29]王迎宾.爪极零件精密塑性成形新工艺研究[D].燕山:燕山大学.2002.
[30]尉哲,谢谈,贾德伟.径向挤压直齿圆柱齿轮的上限分析[J].模具技术,2000,(3):18-22.
[31]S.Sheljaskov. Warm forming-a technology for manufacturing of precision components[J]. Advanced Technology of Plasticity, 1996,(35):317-342.
[32]S.Sheljaskov. Current level of development of warm forging technology[J]. Journal of Materials Processing Technology, 1994,(46):3-18.
[33]胡亚民,车路长.精锻成形技术现状及其发展[J].锻压机械,1996,(3):6-9.
[34]蒋鹏,谢谈.热锻冷锻复合工艺及其应用[J].汽车工艺与材料,2000,(3):6-8.
[35]斯普林格.金属成形技术手册[M].格平根:德国舒勒股份公司,1999:437-440.
[36]Shiyong Yang, Kikuo Nezu. Application of an inverse FE approach in the concurrent design of sheet stamping[J]. J. Mater. Process. Technol,1998, Vol, 79:86-93.
[37]仲町英治(日).基于有限元分析及非线性规划的金属成形过程优化设计[J].中国机械工程,1997,8(4):21-26.
[38]董湘怀,仲盯英治.晶体塑性模型在板材成形计算机模拟中的应用[J].中国机械工程,1997,8(4):27-30.
[39]董湘怀,黄树槐等.塑性加工技术的发展趋势[J].机械工程学报,2000,11(9):1074-1077.
[40]《轻金属材料加工手册》编写组.轻金属材料加工手册(下册)[M].北京:冶金工业出版社.566-567.
[41]奇克敏,丁桦.材料成形工艺学[M].北京:冶金工业出版社,2006:159.136-139.
[42]王忠堂,张士宏,莫立华等.镁合金管材挤压工艺与组织性能研究[J].锻压机械,2002,(1):60-63.
[43]西北工业大学.有色金属锻造[M].北京:国防工业出版社,1971:79-83.
[44]曹延欣. 连杆盖温挤模具结构优化设计与分析研究[D].长春:吉林大学,2005.
[45]胡忠.塑性有限元模拟技术的最新进展[J].塑性工程学报,1994,3(1):3～13.
[46]Marcal P V, King I P, Elastic-plastic analysis of two-dimension stress system by the finite element method[J]. Int. J. Mech. Sci. 1967, 9: 143～55.
[47]Hibbitt H D, Marc P V. Rice J R, A finite element formulation for problems of large strain and large displacement[J]. Int. J. Solid Struct, 1970, 6:1069～1087.
[48]李尚健.金属塑性成形过程模拟[J].北京:机械工业出版社,1998:1-174.
[49]王助成,邵敏.有限单元法基本原理和数值方法[M].北京: 清华大学出版社,1997,3:1-3.
[50]陈如欣,胡中民.塑性有限元法及其在金属成形中的应用[M].重庆:重庆大学出版社2005:144-176.
[51]吕丽萍.有限元法及其在锻压工程中的应用[M].西安:西北工业大学出版社,1989:11-12.
[52]Mogens Arentoft, Zbigniew Gronostajski, Adam Niechajowicz, Tarras Wanheim. Physicaland mathematical modeling of extrusion processes[J].Journal of Materials Processing Technology. 2000,106:2-7.
[53]李尚健.金属塑性成形过程模拟[M].北京:机械工业出版社,1999:142.
[54]彭颖红.金属塑性成形仿真技术[M].上海:上海交通大学出版社,1999.
[55]陈火红.Marc 有限元实例分析教程[M].北京:机械工业出版社,2002:4.
[56]国营漓江机械厂.金属材料手册[M]. 漓江: 国营漓江机械厂标准化室,1974:250-252.
[57]陈振华.变形镁合金[M].北京:化学工业出版社,2005:28.
[58]CHANG Tien-chan, WANAG Jian-Yi.Grain refining of magnesium alloy AZ31 by rolling[J].Materials Prosessing Technology, 2003,140:588-591.
[59]于宝义,乔日金,时海芳等.热处理及挤压比对 AM50 镁合金组织和力学性能的影响[J].铸造,2005,54(11):1076-1078.
[2]杜文博,吴玉锋,左铁镛.镁合金在交通工具中的应用现状[J].世界有色金属,2006,(2):19-21.
[3]周铁城.机械设计选材与强度刚度评估[J].机械工程材料.1996,(8): 40-42.
[4]张士宏,许沂,王忠堂等.镁合金成形加工技术[J].世界科技研究与发展,2002,23(6):18-21.
[5]范光尧,许沂,王忠堂等.机械成形技术与镁合金材料的应用概况[J].工业材料.2000,162(6):139-144.
[6]张青来,卢晨,丁文江.分流挤压镁合金管材工艺研究[J].轻合金加工技术,2003,31(10):28-30.
[7]曾小勤等.镁合金应用新进展[J].铸造.1998,(11):39-43.
[8]潘宪曾.镁合金在中国压铸工业中的应用——世界镁合金压铸与中国[J].铸造,2001,50(6):303～309.
[9]《轻合金材料加工手册》编写组.轻合金材料加工手册(上册)[M].北京:冶金工业出版社,1980:200～203.
[10]Winany C D. Magnesium Die-Castings in Motor Vehicles An: Smith D S. Magnesium the Lightweight Solution-Automotive Sourcing Special Report[R]. London:Automotive Sourcing UK Ltd,1998:8～9.
[11]王忠堂,张士宏,许沂等.镁合金管材挤压工艺及力能参数实验研究[J].沈阳工业学院学报,2001,20(4):66-69.
[12] Chen C C, Kobayashi S. Rigid plastic finite element analysis of ring compreesion[J]. Application of Numerical Methods to Forming Processes, ASME, AMD, 1978,V28,163.
[13] Oh S I, Rebelo N, Kobayashi S. Finte element formulation far the analysis of plastic deformation of rate-sensitive materials in metal forming[J]. Metal Forming Plasticity, Ed. By H. Lippmann, Springer Verlen, 1979,273.
[14]Li G J, Kobayashi S. Rigid plastic finite element analysis of plane strain rolling[R]. Trans. ASME, J. Eng. Ind, 1982, V104.
[15]李良福.热挤压镁合金管子的新工艺[J].铝加工,2002,25(1):20-23.
[16]张士宏,徐希,王忠堂.镁合金管件挤压工艺[J].世界科技研究与发展,2001, 23(6): 18-21.
[17]翟秋亚等.挤压变形 AZ31 镁合金组织和性能的影响[J].西安理工大学学报,2002,18(3): 254-258.
[18]汪凌云,潘复生,丁培道等.AZ31 镁合金成形性能改善研究[J].2002 年材料科学与工程进展,北京:冶金工业出版社,1980,636-640.
[19]彭大署.金属塑性加工原理[M].长沙:中南大学出版社,200.
[20]Yuanyuan Li, Datong Zhang, Feng Liu, Yan Long, and Weiping Chen. Microstructure and tensile behavior of hot extruded AZ91 alloys at room temperature[J]. Matreial Process Technology, 2002, 9(5): 352-356.
[21]Hartley Petc. Numerical Modeling of Material Deformation Process[J]. Springer-Verlag London Limited, 1992.
[22]Akihiro Yamashita, Zenji Horita, Terence G. Langdon. Improving the mechanical properties of magnesium and a magnesium alloy through severe plastic deformation[J]. Materials Science and Engineering A 300. 2001,142-147.
[23]赵新海,赵国群,王广春.金属体积成形预成形设计的现状及发展[J].塑性工程学报,2000,7(3):1-6.
[24]万胜狄.金属塑性成形原理[J].北京:机械工业出版社,1995:157.
[25]小坂田宏造,花见真司,王昕.ュンテナな驱动する锻造加工研究[C].第 5 回中日精密锻造シソポツウム论文集,1996:89-92.
[26]谢建新,刘静安.金属挤压理论与技术[M].北京:冶金工业出版社,2001:193-199.
[27]松下富春.锻造の温度,その选择意义[J].塑性と加工,1999,(40):35-40.
[28]吉村豹治,筱崎吉太郎.闭塞锻造によるネツトシュィプ锻造加工法[J].塑性と加工,2000,(10):18-21.
[29]王迎宾.爪极零件精密塑性成形新工艺研究[D].燕山:燕山大学.2002.
[30]尉哲,谢谈,贾德伟.径向挤压直齿圆柱齿轮的上限分析[J].模具技术,2000,(3):18-22.
[31]S.Sheljaskov. Warm forming-a technology for manufacturing of precision components[J]. Advanced Technology of Plasticity, 1996,(35):317-342.
[32]S.Sheljaskov. Current level of development of warm forging technology[J]. Journal of Materials Processing Technology, 1994,(46):3-18.
[33]胡亚民,车路长.精锻成形技术现状及其发展[J].锻压机械,1996,(3):6-9.
[34]蒋鹏,谢谈.热锻冷锻复合工艺及其应用[J].汽车工艺与材料,2000,(3):6-8.
[35]斯普林格.金属成形技术手册[M].格平根:德国舒勒股份公司,1999:437-440.
[36]Shiyong Yang, Kikuo Nezu. Application of an inverse FE approach in the concurrent design of sheet stamping[J]. J. Mater. Process. Technol,1998, Vol, 79:86-93.
[37]仲町英治(日).基于有限元分析及非线性规划的金属成形过程优化设计[J].中国机械工程,1997,8(4):21-26.
[38]董湘怀,仲盯英治.晶体塑性模型在板材成形计算机模拟中的应用[J].中国机械工程,1997,8(4):27-30.
[39]董湘怀,黄树槐等.塑性加工技术的发展趋势[J].机械工程学报,2000,11(9):1074-1077.
[40]《轻金属材料加工手册》编写组.轻金属材料加工手册(下册)[M].北京:冶金工业出版社.566-567.
[41]奇克敏,丁桦.材料成形工艺学[M].北京:冶金工业出版社,2006:159.136-139.
[42]王忠堂,张士宏,莫立华等.镁合金管材挤压工艺与组织性能研究[J].锻压机械,2002,(1):60-63.
[43]西北工业大学.有色金属锻造[M].北京:国防工业出版社,1971:79-83.
[44]曹延欣. 连杆盖温挤模具结构优化设计与分析研究[D].长春:吉林大学,2005.
[45]胡忠.塑性有限元模拟技术的最新进展[J].塑性工程学报,1994,3(1):3～13.
[46]Marcal P V, King I P, Elastic-plastic analysis of two-dimension stress system by the finite element method[J]. Int. J. Mech. Sci. 1967, 9: 143～55.
[47]Hibbitt H D, Marc P V. Rice J R, A finite element formulation for problems of large strain and large displacement[J]. Int. J. Solid Struct, 1970, 6:1069～1087.
[48]李尚健.金属塑性成形过程模拟[J].北京:机械工业出版社,1998:1-174.
[49]王助成,邵敏.有限单元法基本原理和数值方法[M].北京: 清华大学出版社,1997,3:1-3.
[50]陈如欣,胡中民.塑性有限元法及其在金属成形中的应用[M].重庆:重庆大学出版社2005:144-176.
[51]吕丽萍.有限元法及其在锻压工程中的应用[M].西安:西北工业大学出版社,1989:11-12.
[52]Mogens Arentoft, Zbigniew Gronostajski, Adam Niechajowicz, Tarras Wanheim. Physicaland mathematical modeling of extrusion processes[J].Journal of Materials Processing Technology. 2000,106:2-7.
[53]李尚健.金属塑性成形过程模拟[M].北京:机械工业出版社,1999:142.
[54]彭颖红.金属塑性成形仿真技术[M].上海:上海交通大学出版社,1999.
[55]陈火红.Marc 有限元实例分析教程[M].北京:机械工业出版社,2002:4.
[56]国营漓江机械厂.金属材料手册[M]. 漓江: 国营漓江机械厂标准化室,1974:250-252.
[57]陈振华.变形镁合金[M].北京:化学工业出版社,2005:28.
[58]CHANG Tien-chan, WANAG Jian-Yi.Grain refining of magnesium alloy AZ31 by rolling[J].Materials Prosessing Technology, 2003,140:588-591.
[59]于宝义,乔日金,时海芳等.热处理及挤压比对 AM50 镁合金组织和力学性能的影响[J].铸造,2005,54(11):1076-1078.