Room and cryogenic deformation behavior of AZ61 and AZ61-xCaO (x = 0.5, 1 wt.%) alloy.

Autor: Chaudry, Umer Masood, Tariq, Hafiz Muhammad Rehan, Ansari, Nooruddin, Lee, Soo Yeol, Jun, Tea-Sung
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Zdroj: Journal of Magnesium & Alloys; May2024, Vol. 12 Issue 5, p1996-2009, 14p
Abstrakt: • Room and cryogenic deformation behavior of AZ61 and AZ61-CaO alloys was investigated. • IGMA analysis showed the higher prismatic slip activity in AZ61-CaO alloys. • Numerus twins and twin-twin interactions lead to significant hardening at CT. • Dislocation strengthening was found to be major strengthening mechanisms. This study investigates the influence of CaO (0.5, 1 (wt.%)) alloying on the microstructural evolution, texture development and deformation behavior of AZ61 magnesium alloy. The uniaxial tension tests at room (RT) and cryogenic (CT, -150 °C) temperature were performed to investigate the twinability and dislocation behavior and its consequent effect on flow stress, ductility and strain hardening rate. The results showed that the AZ61-1CaO exhibited superior strength/ductility synergy at RT with a yield strength (YS) of 223 MPa and a ductility of 23% as compared to AZ61 (178 MPa, 18.5%) and AZ61-0.5CaO (198 MPa, 21%). Similar trend was witnessed for all the samples during CT deformation, where increase in the YS and decrease in ductility were observed. The Mtex tools based in-grain misorientation axis (IGMA) analysis of RT deformed samples revealed the higher activities of prismatic slip in AZ61-CaO, which led to superior ductility. Moreover, subsequent EBSD analysis of CT deformed samples showed the increased fraction of fine {10-12} tension twins and nucleation of multiple {10-12} twin variants caused by higher local stress concentration at the grain boundaries, which imposed the strengthening by twin-twin interaction. Lastly, the detailed investigations on strengthening contributors showed that the dislocation strengthening has the highest contribution towards strength in all samples. [Display omitted] [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index
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