Abstract

The generation of a large number of tangled dislocations and subgrain boundaries by dislocation pileups in the stir cast AI-6'2 wt-%Si alloy was observed by a transmission electron microscopy (TEM) study. Misorientations between grains were measured by selected area diffraction (SAD) and convergent beam electron diffraction (CBED) patterns. The density and entanglement of dislocations increased with higher solid fraction (or shear stress) and higher shear rate as a result of increased plastic strain. Longer isothermal stirring time gave rise to higher dislocation density and smaller subgrain size. The meltoff of high angle boundaries, which was suggested by Vogel-Doherty-Cantor's grain boundary melting model, is supported by the observation of subgrain boundaries owing to dislocation pileups during semisolid stirring.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.