钛合金切削绝热剪切带形成过程的有限元分析  

Finite element analysis of adiabatic shear band formation in titanium alloy cutting process

作　　者：杨勇[1] 柯映林[1] 董辉跃[1] 

机构地区：[1]浙江大学机械与能源工程学院,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2008年第3期534-538,共5页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金重点资助项目(50435020);国家"863"高技术研究发展计划资助项目(2006AA04Z147)

摘　　要：采用有限元模拟方法对钛合金切削加工中的绝热剪切带形成过程进行了研究.通过对材料本构模型、刀-屑接触摩擦、切屑分离和绝热剪切等关键物理环节建模,建立了切削加工有限元模型.利用该有限元模型模拟和分析了钛合金TC4切削绝热剪切带形成的全过程,得到了与试验相似的锯齿状切屑,切屑中绝热剪切带分布规律与试验结果较为一致,切削力模拟结果与试验数据相吻合.研究结果表明,刀尖处首先形成小的变形区并逐渐扩展至切屑表面,变形区发生集中滑移,锯齿节块滑出,最终形成变形高度集中的剪切带;绝热剪切带内的温度相当高,而其两侧材料温度较低;绝热剪切带的形成与弹性能释放密切相关,弹性模量越小,切屑锯齿化程度和剪切带间隔时间越大.A finite element model was developed to study the formation process of adiabatic shear band in TC4 cutting. Several key techniques, such as the material constitutive behavior, contact between tool and chip, chip separation and adiabatic shearing, were implemented to improve the accuracy of the finite element simulation. The adiabatic shear band formation process was simulated using this model. The absolute values of the cutting force, chip morphology and distribution law of adiabatic shear band agreed well with the experimental results. The simulation shows that a small plastic deformation zone is formed firstly ahead of the tool tip, which extends to the chip surface gradually, and then the deformation zone shears locally and the saw-tooth segment splits, which finally leading to the formation of shear band that is heavily deformed. The temperature is quite high in the shear band, whereas low in the less deformed region between shear bands. The formation of shear band is correlative with the release of elastic energy, and the lower the elastic modulus is, the higher are the degree of segmentation and the interval time of shear band.

关 键 词：钛合金 切削 有限元模拟 绝热剪切带 热塑性失稳 

分 类 号：TH16[机械工程—机械制造及自动化]