基于不同润滑方式的1D弯曲半径薄壁铝合金管推弯数值模拟和实验研究

Numerical simulation and experimental study on thin-walled aluminum alloy tube push-bending with 1D bending radius based on different lubrication modes

为改善1D弯曲半径的LF2M薄壁铝合金管在推弯中的材料流动状态,基于Abaqus有限元数值模拟,对尺寸为Φ40 mm×1.0 mm的LF2M薄壁铝合金管在均匀润滑和差异化润滑方式下的冷推弯过程进行模拟,分析润滑方式对管直端伸出量的影响,并进行了实验验证。结果表明,均匀润滑方式即减少管坯外表面的摩擦力可以增加成形弯管的直端推出量,改善管壁表面质量,但摩擦力过小会使材料流动过快,导致管壁难以贴模成形或弯曲内侧失稳起皱。差异化润滑方式可改变管坯不同区域的摩擦力大小,促进材料合理流动,增大弯管的直端推出量,改善弯曲内外侧壁厚分布不均等问题。

To improve the material flow state of LF2 M thin-walled aluminum alloy tube with 1 D bending radius,based on Abaqus finite element numerical simulation,the cold push bending process of LF2 M thin-walled aluminum alloy tube with dimension ofΦ40 mm×1.0 mm under homogeneous lubrication and differentiation lubrication modes were simulated to analyze the influence of lubrication mode on the straight end extension of tube and the experimental verification was carried out.The results show that the homogeneous lubrication,that is,reducing the friction force on the outer surface of the tube blank can increase the straight end extension of the formed elbow and improve the surface quality of tube.However,too little friction can cause the material to flow too fast,resulting in that the tube wall is difficult to stick to die forming or the inner side of bending is unstable and wrinkled.Differential lubrication mode can change the friction force in different areas of the tube blank,promote the reasonable flow of material,increase the straight end extension of elbow,and improve the uneven thickness distribution of the inner and outer side of bending.