【作者】 李素丽；

【导师】 张治民；

【作者基本信息】 中北大学 ， 材料加工工程， 2008， 硕士

【摘要】 结合国内外三通件、温挤压及镁合金变形规律和成形工艺的研究成果,针对目前汽车、摩托车上的发动机三通件及自行车车架的三叉接头存在的问题,论证了镁合金AZ31三通件,可以大大减轻车体的重量,采用等温挤压成形,降低了金属的变形抗力,减轻了模具损耗,减少了成形工序,提高了金属的可成形性,这可为镁合金热成形技术的开发研究提供借鉴,具有的普遍意义。本文以有限元仿真制造软件MSC—SuperForm2005为平台,进行了三维有限元数值模拟。分析了三通件等温挤压多向加载整体成形方式—多向同步加载、多向分步加载、多向顺序加载,分别对其加载时间—速度图、金属流动速度矢量图、等效应变图及载荷—行程曲线进行了数值模拟,通过比较,得出多向分步加载,为较合理、省力的工艺方案。针对多向分步加载,着重讨论了不同的变形温度、变形速度和摩擦条件对变形过程等效应变、等效应力以及挤压力—行程曲线的影响,得出在温度350℃、摩擦因子0.01、挤压速度100mm/s的条件下成形性较好,达到制造高精度三通件的目的。根据以上的模拟结果,结合本零件的结构特点,在分析了三通件工艺难点的基础之上,制定了较好的工艺方案。根据此方案选择了合理的毛坯形状、加热温度、润滑剂及挤压力,对此进行了模具设计,并选定了成形设备,达到了预期的目的。更多还原

【Abstract】 According to the domestic and foreign T-shaped tube, the warm extrusion and The Magnesium Alloy distortion rule and the formed craft research results, in view on the present automobile, motorcycle’s engine T-shaped tube and the bicycle frame’s three fork attachment existence questions, have proven the magnesium alloy AZ31 T-shaped tube, may reduce chassis’s weight greatly, use the uniform temperature press forming, reduce the metal resistance of deformation, reduce the mold loss, reduce the formed working procedure, enhance the metal formability, this may provide for the magnesium alloy hot forming technology development research profits from, the universal significance which has.This article takes finite element simulation manufacture software MSC-SuperForm2005 as a platform carried on the three dimensional finite element numerical simulation. Analyze the T-shaped tube uniform temperature extrusion multi-direction load whole forming way multi-direction synchronization to load, the multi-direction distribution to load, the multi-direction order to load, separately to its load time--speed chart, the metal flow velocity vector chart, the equivalent strain chart and the load--traveling schedule curve has carried on the numerical simulation, passed compared with, obtains multi-direction step by step loads for the craft plan which is most reasonable, most reduces effort.In view of the craft plan, discussed the different distortion temperature, the strain rate and the friction condition emphatically to the distortion process equivalent strain, the equivalent stress as well as the extrusion pressure traveling schedule curve influence, obtains in the temperature 350℃, under the friction factor 0.01, extrusion speed 100mm/s condition the forming is best, serves the manufacture high accuracy T-shaped tube purpose.According to the above analogue result, unifies this components the unique feature, in has analyzed above T-shaped tube craft difficulty foundation, has worked out the best craft plan. Has chosen the reasonable semifinished materials shape, the heating temperature, the lubricant and the extrusion pressure according to this plan, regarding this has carried on the mold design, and has designated the complete installation.更多还原