采用焊合区网格重构技术，解决包括分流与焊合过程的空心型材分流模挤压成形全过程温度场模拟问题，以一种典型大断面铝合金空心型材分流模挤压成形为实例，分析挤压速度和坯料温度对模孔出口处型材最高温度及型材横断面温度分布的影响，提出合理的坯料温度和挤压速度范围。结果表明：挤压速度对模孔出口处型材横断面温度分布不均匀性的影响较大，而坯料温度的影响较小：当挤压速度由0.6 mm/s增大到3.0 mm/s，坯料温度为500℃时，模孔出口处型材横断面上最高与最低温度的差值(最大温差)由28℃增大到60℃；而当挤压速度一定，坯料温度在480~520℃变化时，型材横断面上最大温差的变化不超过3℃。6005A型材的合理挤压条件：坯料温度520℃时，挤压速度范围为0.63~0.93 mm/s；坯料温度500℃时，挤压速度范围为0.87~1.14 mm/s；坯料温度480℃时，挤压速度范围为1.10~1.34 mm/s。
The precision simulation problem of the temperature field of hollow profile during the whole extrusion process, including the dividing and welding stages, was solved by mesh reconstruction technology of welding zone. Taking the porthole die extrusion of a typical aluminum hollow profile with large cross section as an example, the effects of billet temperature and extrusion speed on the maximum temperature of profile near the die exit and the temperature distribution on cross section were analyzed, and the reasonable billet temperature and extrusion speed were obtained. The results show that, the influence of the extrusion speed on the inhomogeneous temperature distribution of the cross section of the profile near the die exit is significant, while the influence of the billet temperature is not obvious. When the constant billet temperature is 500 ℃, the difference of the highest and lowest temperature (maximum temperature difference) on the profile cross-section increases from 28℃to 60℃with the extrusion speed increasing from 0.6 mm/s to 3.0 mm/s. The changes of maximum temperature difference on the profile cross section are not more than 3 ℃ with the billet temperature varying from 480℃to 520℃at constant extrusion speed. The extrusion conditions are that when the billet temperatures are 520, 500 and 480℃, the reasonable extrusion speed ranges are 0.63~0.93 mm/s, 0.87~1.14 mm/s and 1.10~1.34 mm/s, respectively.
参考文献
| [1] | 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,2012 |
| [2] | XIE J X;MURAKAMI T;IKEDA K;TAKAHASHI H .Experimental simulation of metal flow in porthole-die extrusion[J].Journal of Materials Processing Technology,1995,49(1/2):1-11. |
| [3] | 何钊,王赫男,王孟君,李光耀.复杂铝型材挤压过程的模拟与试模[J].中国有色金属学报（英文版）,2012(07):1732-1737. |
| [4] | J. Zhou;L. Li;J. Duszczyk .Computer simulated and experimentally verified isothermal extrusion of 7075 aluminium through continuous ram speed variation[J].Journal of Materials Processing Technology,2004(2):203-212. |
| [5] | H.H. Jo;S.K. Lee;C.S. Jung .A non-steady state FE analysis of Al tubes hot extrusion by a porthole die[J].Journal of Materials Processing Technology,2006(2):223-231. |
| [6] | LI L X;LOU Y .Ram speed profile design for isothermal extrusion of AZ31 magnesium alloy by using FEM simulation[J].Transactions of Nonferrous Metals Society of China,2008,18(01):s252-s256. |
| [7] | 邸利青,张士宏.分流组合模挤压过程数值模拟及模具优化设计[J].塑性工程学报,2009(02):123-127,143. |
| [8] | Wu Xianghong;Zhao Guoqun;Luan Yiguo .Numerical simulation and die structure optimization of an aluminum rectangular hollow pipe extrusion process[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2006(0):266-274. |
| [9] | L. Li;H. Zhang;J. Zhou;J. Duszczyk;G.Y. Li;Z.H. Zhong .Numerical and experimental study on the extrusion through a porthole die to produce a hollow magnesium profile with longitudinal weld seams[J].Materials & design,2008(6):1190-1198. |
| [10] | ZHANG Z H;HOU W R;HUANG D N;XIE J X .Mesh reconstruction technology of welding process in 3D FEM simulation of porthole extrusion and its application[J].Procedia Engineering,2012,36:253-260. |
| [11] | 黄东男,李静媛,张志豪,谢建新.方形管分流模双孔挤压过程中金属的流动行为[J].中国有色金属学报,2010(03):488-495. |
| [12] | 黄东男,张志豪,李静媛,谢建新.焊合室深度及焊合角对方形管分流模挤压成形质量的影响[J].中国有色金属学报,2010(05):954-960. |
| [13] | 谢建新;黄东男;李静媛;张志豪 .一种空心型材分流模挤压焊合过程数值模拟技术[P].中国,ZL 20091008896.7,2009-12-16. |
| [14] | 黄东男 .模具结构对铝合金型材挤压流动变形行为的影响[D].北京:北京科技大学材料科学与工程学院,2010. |
| [15] | 肖亚庆;谢水生;刘静安;王涛.铝加工技术实用手册[M].北京:冶金工业出版社,2004 |
| [16] | Gang Fang;Jie Zhou;Jurek Duszczyk .FEM simulation of aluminium extrusion through two-hole multi-step pocket dies[J].Journal of Materials Processing Technology,2009(4):1891-1900. |
| [17] | 刘静安,盛春磊,王文琴.铝合金挤压在线淬火技术[J].轻合金加工技术,2010(02):7-15. |
| [18] | LAUE K;STENGER H.Extrusion[M].Ohio:American Society for Metals,1981 |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%