成形温度对铝合金型材挤压-弯曲一体化成形回弹及截面畸变的影响  

Influence of forming temperature on springback and cross-section distortion for aluminum alloy profile during extrusion-bending integration forming

作　　者：许亮 徐从昌[1] 李落星[1] Xu Liang;Xu Congchang;Li Luoxing(College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学机械与运载工程学院,湖南长沙410082

出　　处：《锻压技术》2021年第9期154-162,共9页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(U20A20275)。

摘　　要：采用实验与仿真相结合的方法,研究了成形温度对挤压-弯曲一体化成形铝合金方管型材的回弹和截面畸变的影响规律及机理,并与冷拉弯工艺进行了对比分析。结果表明:影响回弹量的主要因素是材料屈服强度与弹性模量的比值,该比值越高,型材的回弹量越大,反之则越小;挤压-弯曲时,材料挤出模口后仍处于温热状态,该比值较低,回弹量比T4态、T6态冷拉弯型材减小约50%和75%。截面畸变由外侧拉应力主导,外侧材料的流动不均匀引起型材截面的变形,而型材内侧表面在弯曲模刚性支撑下的变形相对较小;在挤压-弯曲一体化成形工艺中,材料在高温状态下的均匀变形能力好,在0.15 kN的牵引力下,其中心位置处的截面畸变量相较于T4、T6态分别减小约85%和77%。The influence laws and mechanism of forming temperature on springback and cross-section distortion of 6063 aluminum alloy square tube profile formed by extrusion-bending integration forming process and mechanism were explored by the method combining with experiment and simulation,and the comparative analysis were conducted by comparing with cold stretch-bending process.The results show that the main factor affecting the springback is the ratio of yield strength to elastic modulus,the greater the ratio of yield strength to elastic modulus,the greater the springback of the profile,and vice versa.In the extrusion-bending process,the material is still in a warm state after extruded from the mold,the ratio of the yield strength to the elastic modulus is low,the springback of the extrusion-bending profile is about 50%and 75%less than that of the cold stretch-bending profile of T4 state and T6 state respectively.In addition,the cross-sectional distortion is dominated by the external tensile stress,the uneven flow of the external material causes the cross-section distortion of the profile,while the deformation of the inner surface of the profile under the rigid support of the bending mold is relatively small.In the extrusion-bending integrated forming process,the uniform deformation ability of the material at high temperature is good,and with a traction force of 0.15 kN,the cross-section distortion at the center position of the profile is reduced by about 85%and 77%respectively compared with that of T4 state and T6 state.

关 键 词：铝型材 挤压-弯曲一体化成形 回弹 截面畸变 尺寸精度 

分 类 号：TG376[金属学及工艺—金属压力加工]