Abstract
Mg alloys have poor formability due to their hexagonal tightly packed (HCP) crystal structure, low active shear system at room temperature, and anisotropic behavior in polycrystalline structure. While this situation hindered the development and commercialization of Mg alloys to some extent in the past, today developments in machining, liquid forming and semi-solid forming technology have removed these obstacles. Semi-solid forming of alloys has been the subject of intense R&D since it was discovered in the 1970s. In the semi-solid forming method, it is aimed to obtain ideal microstructure of the alloy, including excellent fluidity, appropriate flow control, adjustable viscosity and controllable grain morphology, thanks to equiaxed spherical solid particles surrounded by liquid. In this study, it is aimed to achieve the spherical microstructure required for the semi-solid shaping of the extruded AZ31 Mg alloy by heating to semi-solid temperatures and isothermal holding in the semi-solid temperature range. To accomplish this objective, rapid heating in the induction coil and controlled holding in the isothermal temperature range were applied to the alloy. Heating the extruded AZ31 Mg alloy to a semi-solid temperature (565-630°C) and subsequently rapid cooling processes lead to many intermetallic Mg17Al12(γ) compounds with heterogeneous distribution both in the equiaxed primary Mg(α) grains and at the grain boundaries as well as a very little eutectic at the grain boundaries. As the semi-solid temperature value increased, the degree of spheroidization increased. However, it was found that the grain growth reached a maximum at one point and there was no significant change in the shape factor as a result of controlled holding time.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji
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.