Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5455813 | Materials Science and Engineering: A | 2017 | 19 Pages |
Abstract
Mg-8.0Gd-3.7Y-0.3Ag-0.4Zr (wt%) bulk sample with exceptional high strength is successfully fabricated by multidirectional forging (MDF) and subsequent ageing treatment. The microstructure evolution and mechanical properties are investigated in this study. Results show that grain refining process during MDF is closely related to the dynamic recrystallization (DRX) behavior and a microstructure consisting of ultra-fine grains (~ 0.8 µm) and dynamic precipitates of Mg5(GdY) is obtained when forged by 15 passes (Σ ε = 4.5). After peak-ageing treatment, densely distributed β' phase precipitates out from the matrix. Ag is mainly segregated in the dynamic precipitates. The forging-T5 sample (15 passes) exhibits a room mechanical property of 391 MPa in YS, 448 MPa in UTS and 3.9% in elongation to failure. The strength retains 339 MPa in YS and 411 MPa in UTS when tested at 200 °C. The remarkable mechanical performance can be ascribed to the intensive grain refinement by MDF process, dynamic precipitates as well as precipitate strengthening by β' phase.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Bizheng Wang, Chuming Liu, Yonghao Gao, Shunong Jiang, Zhiyong Chen, Zhen Luo,