AZ31镁合金超细丝材大塑性冷拉拔变形机制与尺寸效应

Magnesium alloy wire and ultrafine wire have a very broad application prospects in the welding, medical, microelectronics and other fields. However, the hexagonal lattice structure of magnesium alloy makes the magnesium alloy wire, especially the ultrafine wire very difficult to be formed. This project proposes the use of single-channel small deformation, multi-channel temperature drawing large plastic deformation and supplemented by static recrystallization process to prepare AZ31 magnesium alloy superfine wire with minimum diameter of 0.05~0.5mm. The microstructural evolution and mechanical properties of the cold drawing and annealing process were systematically characterized. The mechanism of plastic deformation was obtained during the room temperature drawing process. The influence of cold deformation and static recrystallization on the recrystallization structure was revealed. The relationship between the diameter-grain size-mechanical properties was established, and the size effect and influence mechanism of the AZ31 magnesium alloy superfine filament were revealed, and theoretical model were presented. The implementation of the project can expand the applications of magnesium alloy and enrich theories of its forming.

镁合金细丝和超细丝材在焊接、医学、微电子等领域有着广阔的应用前景，但镁合金密排六方的晶格结构使镁合金丝材尤其是超细丝材极难成型，本项目提出采用单道次小变形量、多道次室温拉拔的大塑性变形并辅以静态再结晶退火的工艺，制备直径为0.05~0.5mm的AZ31镁合金超细丝材，对变形态及再结晶退火处理后丝材的微观组织及力学特性进行了系统表征分析，获得超细丝材室温拉拔过程中塑性变形机制；阐明冷变形量与静态再结晶工艺对再结晶组织的影响规律；建立丝材直径-晶粒尺寸-力学性能三者之间的关联关系；揭示AZ31镁合金超细丝材的尺寸效应并构建理论模型。项目的实施可拓展镁合金的应用领域，丰富镁合金成型理论。

镁合金细丝和超细丝材在焊接、医学、微电子等领域有着广阔的应用前景，但镁合金密排六方的晶格结构使镁合金丝材尤其是超细丝材极难成型，本项目提出采用单道次小变形量、多道次热拉拔的大塑性变形并辅以静态再结晶退火的工艺，制备AZ31镁合金超细丝材，对变形态及再结晶退火处理后丝材的微观组织及力学特性进行了系统表征分析，获得超细丝材热拉拔过程中塑性变形机制；阐明变形量与静态再结晶工艺对再结晶组织的影响规律；分析不同累积变形程度和不同退火工艺下的AZ31镁合金热拉拔丝材的拉伸断裂行为；建立丝材直径-晶粒尺寸-力学性能三者之间的关联关系；揭示AZ31镁合金超细丝材的尺寸效应并构建理论模型。项目的实施可拓展镁合金的应用领域，丰富镁合金成型理论。