Influence of Ca+Bi on tensile and strain hardening behaviour of AZ91 alloy

Abstract

The influence of Ca + Bi on the tensile and strain hardening behaviour of the AZ91 alloy at ambient and elevated temperatures have been examined. The values of YS are higher, and ductility is lower of all the modified alloys. The UTS of the modified AZ91 alloys is lower except at 473 K. The UTS values decrease with an increase in test temperature for all the alloys. The improved YS of the modified alloys is owing to reduced grain size. The brittle Mg₃Bi₂, Al₂Ca and Bi₃Ca₅ phases in the modified alloys reduce their UTS and ductility. The transgranular cleavage fracture at 298 K changes to quasi-cleavage fracture at 473 K. Several dislocations piled up around the β-Mg₁₇Al₁₂ and Al₂Ca phases are seen.

KEYWORDS:

• AZ91 alloy
• squeeze-cast
• tensile deformation
• strain hardening

Acknowledgements

One of the authors, A. K. Mondal gratefully acknowledge the receipt of ‘Seed grant for new faculty’ from the Indian Institute of Technology (BHU) Varanasi, India (Sanction No. IIT (BHU)/R&D/SM/ 2018-19/4530/L dated 05.02.2019) to procure the magnesium melting facility with squeeze casting employed in the present work.

Disclosure statement

No potential conflict of interest was reported by the authors().

Additional information

Funding

This work was supported by the Indian Institute of Technology (BHU) Varanasi: [Grant Number No. IIT (BHU)/R&D/SM/ 2018-19/4530/L dated 05.02.2019].