新的等通道转角挤压工艺路径研究

等通道转角挤压(ECAP)是目前制备块状超细晶粒材料最具工业前景的工艺之一,研究ECAP变形机理从而优化工艺参数具有十分重要的意义。自主研究了一种不同于现有的挤压路径。通过塑性成形软件DEFORM-3D对Bc路径和45路径挤压过程进行模拟比较,分析了两种路径挤压过程中等效应变值及等效应力随挤压道次的变化规律。用两种路径分别对试样挤压8和16道次后,45路径产生的等效应变值均略高于Bc路径;8道次过后,45路径形成的等效应变值分布范围也比Bc路径更集中;但16道次过后,Bc路径形成的等效应变值分布范围比45路径集中。随着挤压道次的增加,两种路径形成的等效应变值的上升趋势基本一致,等效应力基本保持不变。研究表明:45路径具有细化能力强,变形剧烈和变形均匀等优点,是一种有效的新的ECAP挤压路径。

Study on New Process of Equal Channel Angular Pressing

As an effective method for obtaining the nanometer materials , ECAP is considered to be most promising process for the preparation of ultra -fine grain materials .It is significant to study the theory of deformation for refining the process parameters .In this paper a new pressed route -45 route was studied , and the changing rule between , effective strain and effective stress, and two pressed routes were analyzed through the DEFORM -3D.As results show, the effective strain of 45 route is always slightly higher than Bc route after pressed 8 and 16 times, and the distribution of effective strain of 45 route is more concentrated than Bc route after pressed 8 times.However, Bc route is more concentrated after pressed 16 times.The changing rule of the effective strain is correspond to pressed times , and the effective stress of two routes is almost remain unchanged .Our studies show that the 45 route is a new effective route of ECAP with the advantages of refi-ning capacity , intense and uniform deformation .