【作者】 崔财威；

【导师】 方敏；

【作者基本信息】 中北大学 ， 材料加工工程， 2012， 硕士

【摘要】 本课题涉及的零件内外均有加强筋，整体截面复杂，并非规整的轴对称零件。原采用钢板焊接而成，重量大，且存在焊接缺陷。本文采用7A04铝合金代替钢板材料，采用等温精密塑性成形技术代替焊接工艺，在现有设备的基础上来成形零件，旨在保证零件性能要求的前提下来减重。本文对很多相似工件的减重以及复杂截面零件的成形具有一定的参考意义。本课题采用DEFORM‐3D计算机数值模拟软件结合实验试制的研究方法。对初步拟定的工艺方案进行数值模拟，发现工件内表面加强筋部容易发生折叠、填充不满，以及金属流动速度相差较大影响工件各部位的成形，而且成形载荷达到了2800t，现有的设备并不满足。通过对这一系列问题的分析研究，制定了新的成形工艺方案来消除初步拟定的工艺方案中的缺陷，即：下料→预成形坯料→正挤压底部→局部成形工件内部→整形。对新制定的工艺方案模拟优化，分析模拟过程中金属流动速度矢量图、等效应变分布图、载荷等，未发现缺陷，工件整体变形量比较均匀，载荷从2800t降低到1200t左右，符合现有的成形设备。在模拟基础上设计制造出模具并进行实验试制，结果表明：采用等温精密塑性成形技术逐步成形工件，不仅能够减少缺陷的产生，有效降低成形载荷，而且成形后工件的力学性能较好；试制出的工件与模拟结果相吻合，表面尺寸精度高，力学性能完全达到了要求；机加后的工件重量达到了10Kg，相比原工艺成形件减重达30%，达到了轻量化的要求。更多还原

【Abstract】 Parts involved in this topic have ribs both inside and outside, Cross‐section is complex, and it is not axisymmetric. The original process was welded together by a steel plate, weighing is large, and it may have some welding defects. In this research, 7A04 aluminum alloy be used instead of steel, and use technology of Isothermal precision plastic forming instead of welding. Forming parts on the basis of our existing equipment, Aims to Weight loss on the premises of part excellent performance. This topic will be a certain reference value in weight loss of many similar parts, as well as the forming of complex cross‐section parts.The research method is on DEFORM‐3D computer numerical simulation software combined with experimental. Proposing preliminarily scheme is simulated. There are some problems in the analysis of simulation results, for example: Founding that the stiffener of workpiece folding. And our equipment do not have enough forming load. A new forming process is formulated through the analysis of this series of problems, that is, Blanking→Pier extrusion→Forward extrusion→local forming→Reshaping. New process scheme have be simulated as well as optimized. Flowing velocity vector, equivalent strain and load force of simulation process have be analyzed. There are no obvious defects. Deformation of the workpiece is uniform. Load reduced to about 1200t from 2800t, and it accord with simulation results.Based on the simulation, we design the mold assembly drawing, and trial production. The results show that: The forming of cross‐section parts should not be used directly forming. Otherwise, some of the parts may have a lot of deficiencies that affect performance parts. We use the isothermal precision plastic forming technology to form parts gradually, not only able to reduce defects, but also reduce the forming load, and parts will have the better mechanical properties. Throughout the experimental results and simulation results are consistent. Inside surface of the workpiece have high precision. Forming parts fully meet the performance requirements. Weight of the workpiece after machine‐made is 10Kg. Comparing with previous forming weight loss 30%. Lightweight requirements have achieved.更多还原