ECAP工艺对6061铝合金性能的影响.pdf

南京航空航天大学
硕士学位论文
ECAP工艺对6061铝合金性能的影响
姓名:陈文杰
申请学位级别:硕士
专业:航空宇航制造工程
指导教师:周清
2011-01
南京航空航天大学硕士学位论文
摘要
本文通过数值模拟分析与试验研究相结合的方法开展了 ECAP(Equal channel angular
pressing)工艺的研究。使用 DEFORM-3D 对 6061 铝合金的 ECAP 工艺进行了数值模拟,分析了
ECAP 过程的应力和应变,研究了模具几何形状、挤压路径和挤压道次对裂纹产生和应变均匀性
的影响。应用韧性断裂Normalized Cockcroft & Latham 判据模拟了 ECAP 裂纹萌生的产生区域,
与实际的实验结果相对照,发现吻合得较好。探讨了裂纹产生的原因、预测方法和减小裂纹的
措施。在实际测得的挤压后力学性能的基础上,获得了 6061 铝合金 ECAP 的最佳工艺路径。
关键词:ECAP;数值模拟;裂纹产生;机械性能;6061 铝合金




I
ECAP 工艺对 6061 铝合金性能的影响
ABSTRACT
Both numerical simulation and experimental method were used in this study on multiple passes
ECAP (Equal channel angular pressing) process of 6061 Al alloy. Applying DEFORM-3D, the
effective stress produced and the effective strain accumulated in the process were simulated. The
effects of the processing route, processing pass and the die geometry on the crack formation of the rod
were focused. It was found that by a method of normalized Cockcroft & Latham ductile fracture
criterion, the simulation results of the localization of the crack had good agreement with the exact
experimental results. Based on the above observation, the origin of the crack and the methods of
diminishing crack were discussed. Through measuring the mechanical properties of the ECAPed rod,
we obtain optimum processing route for 6061 Al ECAP.
Keywords:ECAP; numerical simulation; crack damage;mechanical properties; 6061 Al

II
ECAP 工艺对 6061 铝合金性能的影响
图清单
图 ECAP 示意图.....................................................................................................................1
图 ECAP 工艺路径示意图.....................................................................................................3
图 位错形成微裂纹示意图....................................................................................................5
图 铝合金超塑性成形的内燃机活塞....................................................................................6
图 商业钛合金螺纹紧固件...........