Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions

Afsharnaderi, Aria; Malekan, Mehdi; Emamy, Massoud; Rasizadeh Ghani, Jafar; Lotfpour, Mehrab

doi:10.1007/S11665-019-04396-2

Title: Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions

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Abstract

Effect of different amounts of Sr and Ti additions with T6 heat treatment on microstructure and mechanical properties of the AZ91 alloy was investigated. The microstructure of the AZ91 alloy is consisted of the α-Mg phase surrounded by the semicontinuous network of β-Mg{sub 17}Al{sub 12} intermetallics. The average grain size and volume fraction of β phase decreased up to 1 wt.% Sr and 0.1 wt.% Ti additions. Exceeding Ti additions led to increase in both grain size and volume fraction. It was found that the grain refinement mechanism of AZ91 alloys with Sr additions was grain restriction factor. Also, 0.1 wt.% Ti addition could refine the grain structure of the AZ91 alloy by the formation of Al{sub 3}Ti particles that act as nucleation sites for the α-Mg phase. Furthermore, adding 1 wt.% Sr and 0.1 wt.% Ti enhanced the hardness values for both cast and aged AZ91 alloy. Moreover, ultimate tensile strength and tensile elongation values reached their maximum amounts with the 0.5 wt.% Sr and 0.1 wt.% Ti additions and more Sr and Ti additions deteriorated the mechanical properties of cast and aged AZ91 alloys. The fracture surface characterizations had good relations with the tensile properties. The fracture modes were cleavage and quasi-cleavage in the castmore »« less

Authors:

Afsharnaderi, Aria; Malekan, Mehdi; Emamy, Massoud; Rasizadeh Ghani, Jafar; Lotfpour, Mehrab ^[1]

University of Tehran, School of Metallurgy and Materials Engineering, College of Engineering (Iran, Islamic Republic of)

Publication Date:: Fri Nov 15 00:00:00 EST 2019

OSTI Identifier:: 22970359

Resource Type:: Journal Article

Journal Name:: Journal of Materials Engineering and Performance

Additional Journal Information:: Journal Volume: 28; Journal Issue: 11; Other Information: Copyright (c) 2019 ASM International; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1059-9495

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; CLEAVAGE; FRACTURES; GRAIN REFINEMENT; GRAIN SIZE; HARDNESS; HEAT TREATMENTS; INTERMETALLIC COMPOUNDS; MAGNESIUM ALLOYS; TENSILE PROPERTIES

Citation Formats


                    Afsharnaderi, Aria, Malekan, Mehdi, Emamy, Massoud, Rasizadeh Ghani, Jafar, and Lotfpour, Mehrab. Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions.  United States: N. p., 2019. 
        Web.  doi:10.1007/S11665-019-04396-2.

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                    Afsharnaderi, Aria, Malekan, Mehdi, Emamy, Massoud, Rasizadeh Ghani, Jafar, & Lotfpour, Mehrab. Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions.  United States.  https://doi.org/10.1007/S11665-019-04396-2

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                    Afsharnaderi, Aria, Malekan, Mehdi, Emamy, Massoud, Rasizadeh Ghani, Jafar, and Lotfpour, Mehrab. 2019.  
        "Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions".  United States.  https://doi.org/10.1007/S11665-019-04396-2.

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@article{osti_22970359,

  title        = {Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions},

  author       = {Afsharnaderi, Aria and Malekan, Mehdi and Emamy, Massoud and Rasizadeh Ghani, Jafar and Lotfpour, Mehrab},

  abstractNote = {Effect of different amounts of Sr and Ti additions with T6 heat treatment on microstructure and mechanical properties of the AZ91 alloy was investigated. The microstructure of the AZ91 alloy is consisted of the α-Mg phase surrounded by the semicontinuous network of β-Mg{sub 17}Al{sub 12} intermetallics. The average grain size and volume fraction of β phase decreased up to 1 wt.% Sr and 0.1 wt.% Ti additions. Exceeding Ti additions led to increase in both grain size and volume fraction. It was found that the grain refinement mechanism of AZ91 alloys with Sr additions was grain restriction factor. Also, 0.1 wt.% Ti addition could refine the grain structure of the AZ91 alloy by the formation of Al{sub 3}Ti particles that act as nucleation sites for the α-Mg phase. Furthermore, adding 1 wt.% Sr and 0.1 wt.% Ti enhanced the hardness values for both cast and aged AZ91 alloy. Moreover, ultimate tensile strength and tensile elongation values reached their maximum amounts with the 0.5 wt.% Sr and 0.1 wt.% Ti additions and more Sr and Ti additions deteriorated the mechanical properties of cast and aged AZ91 alloys. The fracture surface characterizations had good relations with the tensile properties. The fracture modes were cleavage and quasi-cleavage in the cast and aged AZ91 alloys. Furthermore, the optimum levels of Sr and Ti additions altered the fracture modes to more quasi-cleavage fractures.},

  doi          = {10.1007/S11665-019-04396-2},

  url          = {https://www.osti.gov/biblio/22970359},
  journal      = {Journal of Materials Engineering and Performance},

  issn         = {1059-9495},

  number       = 11,

  volume       = 28,

  place        = {United States},

  year         = {Fri Nov 15 00:00:00 EST 2019},

  month        = {Fri Nov 15 00:00:00 EST 2019}

}

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