Investigation on the Microstructure of ECAP-Processed Iron-Aluminium Alloys

authored by: Bernd Arno Behrens, Kai Brunotte, Tom Petersen, Roman Relge
Abstract: The present work deals with adjusting a fine-grained microstructure in iron-rich iron-aluminium alloys using the ECAP-process (Equal Channel Angular Pressing). Due to the limited formability of Fe-Al alloys with increased aluminium content, high forming temperatures and low forming speeds are required. Therefore, tool temperatures above 1100^◦C are permanently needed to prevent cooling of the work pieces, which makes the design of the ECAP-process challenging. For the investigation, the Fe-Al work pieces were heated to the respective hot forming temperature in a chamber furnace and then formed in the ECAP tool at a constant punch speed of 5 mm/s. Besides the chemical composition (Fe9Al, Fe28Al and Fe38Al (at.%—Al)), the influences of a subsequent heat treatment and the holding time on the microstructure development were investigated. For this purpose, the average grain size of the microstructure was measured using the AGI (Average Grain Intercept) method and correlated with the aforementioned parameters. The results show that no significant grain refinement could be achieved with the parameters used, which is largely due to the high forming temperature significantly promoting grain growth. The holding times in the examined area do not have any influence on the grain refinement.
Organisation(s): Institute of Metal Forming and Metal Forming Machines
Type: Article
Journal: MATERIALS
Volume: 14
No. of pages: 10
ISSN: 1996-1944
Publication date: 05.01.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Materials Science(all)
Electronic version(s): https://doi.org/10.3390/ma14010219 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{18c49e24f4f44e4cbca9fd251f6ad4f7,
title = "Investigation on the Microstructure of ECAP-Processed Iron-Aluminium Alloys",
abstract = "The present work deals with adjusting a fine-grained microstructure in iron-rich iron-aluminium alloys using the ECAP-process (Equal Channel Angular Pressing). Due to the limited formability of Fe-Al alloys with increased aluminium content, high forming temperatures and low forming speeds are required. Therefore, tool temperatures above 1100◦C are permanently needed to prevent cooling of the work pieces, which makes the design of the ECAP-process challenging. For the investigation, the Fe-Al work pieces were heated to the respective hot forming temperature in a chamber furnace and then formed in the ECAP tool at a constant punch speed of 5 mm/s. Besides the chemical composition (Fe9Al, Fe28Al and Fe38Al (at.%—Al)), the influences of a subsequent heat treatment and the holding time on the microstructure development were investigated. For this purpose, the average grain size of the microstructure was measured using the AGI (Average Grain Intercept) method and correlated with the aforementioned parameters. The results show that no significant grain refinement could be achieved with the parameters used, which is largely due to the high forming temperature significantly promoting grain growth. The holding times in the examined area do not have any influence on the grain refinement.",
keywords = "Bulk forming, Equal channel angular pressing (ECAP), Hot forming, Iron-aluminium alloys, Microstructure",
author = "Behrens, {Bernd Arno} and Kai Brunotte and Tom Petersen and Roman Relge",
note = "Funding Information: Funding: This research was funded by the German Research Foundation (DFG), grant number No. 142849202.",
year = "2021",
month = jan,
day = "5",
doi = "10.3390/ma14010219",
language = "English",
volume = "14",
journal = "MATERIALS",
issn = "1996-1944",
publisher = "MDPI AG",
number = "1",
}