|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Multiscale Architectured Materials (MAM II): Tailoring Mechanical Incompatibility for Superior Properties
||Improved Balance of Mechanical Properties in Cryomilled Al-Mg Alloy Through Thermomechanical Processing
||Holden Hyer, Clara Hofmeister, Yongho Sohn, Bhaskar Majumdar
|On-Site Speaker (Planned)
It has been demonstrated in the past that Al-Mg alloys that have been cryomilled in liquid nitrogen exhibit extremely high strength in compression, typically 900-1000 MPa. The nanosize grains and the high nitrogen content (0.5 to 1.5 wt.%) contribute to this behavior. However, elongation to failure is almost zero. In this work we have used slow strain-rate extrusion over a range of temperatures to modify the microstructure, and have demonstrated tensile strength in excess of 725 MPa and elongations ranging from 2 to 5%. It is shown that this attractive balance of tensile properties is obtained through a multiscale microstructure, ranging from 50 nm to 2 micrometers. The mechanical incompatibilities associated with these very different grain size is likely responsible for the good balance of properties. The microstructures and mechanisms will be discussed.