高强铝合金复杂锻件等温可分凹模精密模锻成形工艺研究

Study on isothermal split-die precision forging process of complicated forging of high strength aluminum alloy

以某高强铝合金复杂锻件为研究对象,通过锻件工艺性分析,选用了等温可分凹模模锻精密成形工艺作为其制备工艺,采用热力耦合有限元分析方法对新成形工艺的终成形、预成形、拍扁等3个工序进行了模拟分析。终成形模拟结果表明:具有基本几何特征的预制坯成形后在多个位置形成折叠。通过平面应变有限元模拟获得了这些折叠产生的机理,给出了可分凹模模锻工艺中复杂锻件预制坯设计的基本原则,并优化了预制坯几何外形。工艺试验结果表明,采用修改后的预制坯和新成形工艺制备的锻件无缺陷,其尺寸精度、表面粗糙度等质量指标优于传统开式模锻件。

For a complicated forging of high strength aluminum alloy, the isothermal split-die forging process dealing with final forging, preforming and flatting was numerically simulated by the coupled thermo-mechanical finite element method （FEM） based on process anal- ysis. The FEM resuhs show several folds have been formed in the final forging due to unreasonable geometric shape of preform. The form- ing mechanism causing those folds was obtained by finite element simulation with plane strain model. The design principle of the compli- cated preform forging was given in the split-die forging process, and its geometry was optimized. The experimental results show that the forged piece which manufactured by the new preform and forming process is perfect without any defects, and the overall quality indexes of forged piece, such as dimensional accuracy and surface roughness, are better than that produced by typical open-die forging process.