Novel ultrafine eutectic composites containing structural and spatial heterogeneities have been systematically developed in an Mg-Cu-Zn ternary system. Microstructural investigations of the ultrafine eutectic composites revealed that the bimodal eutectic structure consists of a mixture of cellular-type fine (α-Mg + MgZn2) and anomalous-type coarse (α-Mg + MgZn2 + MgCuZn) eutectic structures. An Mg 72Cu3Zn23 alloy composed of the bimodal eutectic structure without micron-scale α-Mg dendrites presents a strong improvement of yield strength up to 455 MPa with a decent plastic strain of 5%. The rotation of the bimodal eutectic colony along the interfaces is considered to be an effective way to dissipate the stress localization thus enhancing the macroscopic plasticity.
Bibliographical noteFunding Information:
This work was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (R01-2007-000-10549-0) and the Global Research Laboratory (GRL) Program of Korea Ministry of Education, Science and Technology.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering