Examination of the Effect of Cooling Rate after Extrusion to Formability of 6061 Automotive Profiles
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Published:2023-03-15
Issue:6
Volume:13
Page:3763
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ISSN:2076-3417
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Container-title:Applied Sciences
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language:en
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Short-container-title:Applied Sciences
Author:
Vazdirvanidis Athanasios1, Papadopoulou Sofia1, Symeonidis Grigoris2, Aslanis Fivos1, Rikos Andreas1, Stachouli Eva1
Affiliation:
1. ELKEME Hellenic Research Centre for Metals S.A., 61st km Athens–Lamia National Road, 32011 Oinofyta, Greece 2. ETEM-GESTAMP Extrusion Company, Bul. “Iliyantsi” 119, 1220 Sofia, Bulgaria
Abstract
As part of the present project, an inquiry is being conducted into the impact of the cooling rate subsequent to extrusion on both the mechanical characteristics and microstructure of 6061 alloy extruded profiles tailored for application in the automotive industry. Water quenching, air cooling, and step-cooling (combination of air cooling and water quenching) were performed after a solution heat treatment for simulating different cooling processes on the exit of the extrusion press. Microstructure examination was performed after artificial aging for every cooling method accompanied by three-point bending and tensile testing for investigation of differences in formability characteristics in each one of the three cases. Electron fractography, texture, and grain boundary misorientation analysis consisted the main analytical techniques, allowing the correlation between grains orientation resulting from the extrusion process with cracking initiation behavior in mechanical testing and for the determination of the regions which were more prone to cracking. From the examination, the positive role of rapid cooling for improved formability was highlighted. Through the grain boundary misorientation analysis and the formation of Taylor factor maps, it was shown that crack initiation preferably took place at subsurface regions even though “roughening” of the bent surface was obvious and expected to lead to crack initiation in the more ductile samples. Considerable amounts of LAGBs (Low Angle Grain Boundaries) (14.7%) and SGBs (Subgrain Boundaries) (4.5%) were detected in the sample which was subjected to step cooling accompanied by an outer and inner surface layers (surface zone) of 200–250 μm thicknesses exhibiting different orientations. The results of this project will be used for optimization of the automotive extruded profiles production process, ensuring improved mechanical performance and resistance to premature fracture.
Subject
Fluid Flow and Transfer Processes,Computer Science Applications,Process Chemistry and Technology,General Engineering,Instrumentation,General Materials Science
Reference31 articles.
1. Bajor, T., Kawałek, A., Berski, S., Jurczak, H., and Borowski, J. (2022). Analysis of the Extrusion Process of Aluminium Alloy Profiles. Materials, 15. 2. Shen, X., Liu, S., Wang, X., Cui, C., Gong, P., Zhao, L., Han, X., and Li, Z. (2022). Effect of Cooling Rate on the Microstructure Evolution and Mechanical Properties of Iron-Rich Al–Si Alloy. Materials, 15. 3. Xu, Z., Wang, S., Wang, H., Song, H., Li, S., and Chen, X. (2020). Effect of Cooling Rate on Microstructure and Properties of Twin-Roll Casting 6061 Aluminum Alloy Sheet. Metals, 10. 4. Investigation on the deformation behavior and post-formed microstructure/properties of AA7075-T6 alloy under pre-hardened hot forming process;Zhang;Mater. Sci. Eng. A,2020 5. Improvement of the mechanical properties of Al–Mg–Si alloys with nano-scale precipitates after repetitive continuous extrusion forming and T8 tempering;Hu;J. Mater. Res. Technol.,2019
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