|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Deformation Induced Microstructural Modification
||Grain Refinement and Bimodal distribution of precipitates in Al 6xxx and 7xxx alloys during ShAPE (Shear Assisted Processing and Extrusion)
||Xiaolong Ma, Rajib Kalsar, Jens Darsell, Miao Song, Nicole Overman, Keerti Sahithi Kappagantula, Vineet V Joshi
|On-Site Speaker (Planned)
Precipitation of fine intermetallic particles along with grain refinement is a crucial strengthening mechanism for alloys. The control of the particle size and distribution thus plays a key role in thermo-mechanical processing. ShAPE( Shear-assisted Processing and extrusion) is a recently developed appealing technique where rotational shear is superimposed to linear extrusion along with a self-generation of heat. However, how this unique condition affects the precipitation process of alloys still needs to be understood. In this study, we investigate the microstructures of two Al alloys (6061 and 7075) after the extrusion. We show that a bimodal distribution of precipitates is generated universally in both alloys. Particles as large as a few micrometers are often seen along grain boundaries, while small precipitates with less than ~100 nm are primarily dispersed in grain interiors. The results offer critical insight into how to tune the extrusion parameters to enhance the mechanical property of extrudates.