Warm Precision Forging on Extruded AZ61 Magnesium Alloy

温精锻作为塑性成形中直接获得成品形状和高尺寸精度的一体化生产工艺正受到人们的关注。本研究对具有预期高塑性加工性和高强度的AZ 61镁合金挤压坯进行了温精锻研究。本研究旨在找出T形精密锻件的最佳生产条件，并分析其机械性能及织构。此外，还对AZ 61镁合金挤压坯的轴向温镦粗能力进行了评价。这对于具有广泛实际应用的T形锻件，如汽车零件、管接头、阀体等，尤其有用。还研究了AZ 61挤压坯料的轴向温镦粗，作为锻造工艺的基准数据。分析了AZ 61镁合金挤压坯在温轴向压缩过程中的变形行为和失稳变形。结果表明：（1）T形锻件在成形温度为463 K，成形速度为14 mm/min，施加背压为250 kN时，可获得无裂纹锻造。（2）轴向温镦粗时，镦粗能力存在垂直方向的非对称变形，且与择优取向有关。这种现象发生在坯料的上部加载区域中由晶体旋转引起的变形之前。(3)By采用铸造镁合金，在483 K温度下，以3倍或3倍以上的挤压速度获得T形锻件。由于锻造后的硬度和抗压强度都很好，采用铸造镁合金进行锻造技术是一种值得期待的技术。

Warm precision forging is receiving attention as integrated producing process to directly obtain finished product form and high dimensional accuracy in the plastic forming In this research warm precision forging of an AZ61 Magnesium alloy extruded billet with an expected high plastic workability and high strength was investigated. This research aims to find the best condition for producing T-shaped precision forging, and to analyze the resultant mechanical properties and texture. In addition, warm axial upset ability of AZ61 extruded billet is also evaluated. This is particularly useful for T-shaped forging, which have broad practical application, such as automobile parts, pipe joints, valve bodies, etc. For T-shaped forging, the lubricant, temperature and backpressure condition were investigated. Warm axial upsetting of an AZ61 extruded billets is also investigated as the base date of a forging process. Deformation behavior and unstable deformation of AZ61 extruded billets during warm axial compression are also analyzed. Obtained results are as follows:(1)For T-shaped forging, at forming temperature of 463 K, and velocity of 14 mm/min, fracture-free forging with an applied backpressure of 250kN were obtained(2)For upset ability, asymmetrical deformation in the vertical direction was appeared in warm axial upsetting, and is related to the prefer orientation. This phenomenon occurs prior to deformation caused by crystal rotation in the upper loaded region of the billet.(3)By using cast magnesium alloy, T-shaped forging were obtained at the speed three times or more the extruded billets, at 483K. As the both of hardness and compression strength after forged is excellent, forged technology that used the casting magnesium alloy is expected.