(1. 北京科技大學 材料先進制備技術教育部重點實驗室，北京 100083；
2. 機械科學研究總院 先進制造技術研究中心，北京 100083)
摘 要: 采用焊合區(qū)網(wǎng)格重構技術，解決包括分流與焊合過程的空心型材分流模擠壓成形全過程溫度場模擬問題，以一種典型大斷面鋁合金空心型材分流模擠壓成形為實例，分析擠壓速度和坯料溫度對模孔出口處型材最高溫度及型材橫斷面溫度分布的影響，提出合理的坯料溫度和擠壓速度范圍。結果表明：擠壓速度對模孔出口處型材橫斷面溫度分布不均勻性的影響較大，而坯料溫度的影響較小：當擠壓速度由0.6 mm/s增大到3.0 mm/s，坯料溫度為500 ℃時，模孔出口處型材橫斷面上最高與最低溫度的差值(最大溫差)由28 ℃增大到60 ℃；而當擠壓速度一定，坯料溫度在480~520 ℃變化時，型材橫斷面上最大溫差的變化不超過3 ℃。6005A型材的合理擠壓條件：坯料溫度520 ℃時，擠壓速度范圍為0.63~0.93 mm/s；坯料溫度500 ℃時，擠壓速度范圍為0.87~1.14 mm/s；坯料溫度480 ℃時，擠壓速度范圍為1.10~1.34 mm/s。
關鍵字: 空心型材；分流模擠壓成形；網(wǎng)格重構；溫度場
（1. Key Laboratory for Advanced Materials Processing, University of Science and Technology Beijing,
Beijing 100083, China;
2. Advanced Manufacture Technology Center, China Academy of Machinery Science and Technology,
Beijing 100083, China）
Abstract: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.
Key words: hollow profile; porthole die extrusion forming; meshes reconstruction; temperature field
