Meng Shuaiju, Dong Lishan, Yu Hui, Huang Lixin, Han Haisheng, Cheng Weili, Feng Jianhang, Wen Jingjing, Li Zhongjie, Zhao Weimin
School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China.
CITIC Dicastal Co., LTD, Qin Huangdao 066011, China.
Materials (Basel). 2020 Feb 5;13(3):709. doi: 10.3390/ma13030709.
An exceptionally high-strength rare-earth-free Mg-8Al-3Bi (AB83) alloy was successfully fabricated via extrusion and caliber rolling. After three-pass caliber rolling, the homogenous microstructure of the as-extruded AB83 alloy was changed to a necklace-like bimodal structure consisting of ultra-fine dynamic recrystallized (DRXed) grains and microscale deformed grains. Additionally, both MgAl and MgBi nanoprecipitates, undissolved microscale MgAl, and MgBi particles were dispersed in the matrix of caliber-rolled (CRed) AB83 alloy. The CRed AB83 sample demonstrated a slightly weakened basal texture, compared with that of the as-extruded sample. Consequently, CRed AB83 showed a tensile yield strength of 398 MPa, an ultimate tensile strength of 429 MPa, and an elongation of 11.8%. The superior mechanical properties of the caliber-rolled alloy were mainly originated from the combined effects of the necklace-like bimodal microstructure containing ultra-fine DRXed grains, the homogeneously distributed nanoprecipitates and microscale particles, as well as the slightly modified basal texture.
通过挤压和径锻成功制备了一种高强度无稀土的Mg-8Al-3Bi（AB83）合金。经过三道次径锻后，挤压态AB83合金的均匀微观结构转变为一种项链状双峰结构，该结构由超细动态再结晶（DRXed）晶粒和微米级变形晶粒组成。此外，MgAl和MgBi纳米析出相、未溶解的微米级MgAl和MgBi颗粒均分散在径锻（CRed）AB83合金的基体中。与挤压态样品相比，CRed AB83样品的基面织构略有减弱。因此，CRed AB83的抗拉屈服强度为398MPa，极限抗拉强度为429MPa，伸长率为11.8%。径锻合金优异的力学性能主要源于包含超细DRXed晶粒的项链状双峰微观结构、均匀分布的纳米析出相和微米级颗粒以及略有改变的基面织构的综合作用。
