Abstract
Aluminum alloy in situ functionally graded materials (FGMs) have been successfully fabricated using directional solidification under an axial static magnetic field. Al-Zn, Al-Ni and Al-Cu alloys with a hypereutectic composition were selected to produce FGMs. Experimental results show that the graded composition of the primary phases (i.e., Zn, Al3Ni and Al2Cu) is obvious along the longitudinal section of the sample. The graded composition of the primary phases could be controlled by the value of the magnetic field, growth rate and temperature gradient. A proposed model and simulations are carried out to explain the origin of the graded composition of the primary phases in FGMs during directional solidification under an axial static magnetic field. It should be attributed to the combined actions of heavier species migration under gravity force and thermoelectric (TE) magnetic convection under magnetic field. Furthermore, it can be found that the magnetic field can induce the columnar FGMs to change into equiaxed FGMs. This work not only presents a new approach to fabricate FGMs using the directional solidification under an axial static magnetic field but also deeply understands the effect of the solute migration and temperature distribution on the crystal growth during directional solidification.
Highlights
Graded material (FGM) is a composite of multi-phase microstructure
The present work describes an in situ technique to fabricate Al alloy functionally graded materials (FGMs) (i.e., Al-Zn, Al-Ni and Al-Cu alloys) using directional solidification under an axial static magnetic field
The magnetic field can induce columnar FGMs to change into equiaxed FGMs
Summary
Graded material (FGM) is a composite of multi-phase microstructure. FGMs have attracted long-term attentions since Japan’s FGMs programmes began. The static magnetic field, causing TE magnetic convection and solute migration during directional solidification, can be applied to fabricate FGMs during directional solidification. The present work describes an in situ technique to fabricate Al alloy FGMs (i.e., Al-Zn, Al-Ni and Al-Cu alloys) using directional solidification under an axial static magnetic field. A proposed model and simulations are carried out to explain the origin of the graded composition of the primary phases in FGMs. the magnetic field can induce columnar FGMs to change into equiaxed FGMs. This work presents a new approach to fabricate FGMs using the directional solidification under an axial static magnetic field and deeply understands the effect of the solute migration and temperature distribution on the crystal growth during directional solidification
Sign-in/Register to view highlights & summary 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 callDisclaimer: 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.
