Challenges in the Forging of Steel-Aluminum Bearing Bushings

authored by

Bernd-Arno Behrens, Johanna Uhe, Tom Petersen, Christian Klose, Susanne Thürer, Julian Diefenbach, Anna Chugreeva

Abstract

The current study introduces a method for manufacturing steel–aluminum bearing bush-ings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing Fe

_x Al

_y phase in the resulting intermetallic layer.

Organisation(s)

Institute of Metal Forming and Metal Forming Machines
Institute of Materials Science

Type

Article

Journal

MATERIALS

Volume

Pages

1-14

No. of pages

ISSN

1996-1944

Publication date

08.02.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Materials Science(all)

Electronic version(s)

https://doi.org/10.3390/ma14040803 (Access: Open)

Details in the research portal "Research@Leibniz University"

BibTeX

@article{9664458396eb447d978c3651b7fe30c2,
title = "Challenges in the Forging of Steel-Aluminum Bearing Bushings",
abstract = "The current study introduces a method for manufacturing steel–aluminum bearing bush-ings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing Fe x Al y phase in the resulting intermetallic layer. ",
keywords = "Bimetal bearing bushing, Compound forging, Hybrid components, Induction heating, Intermetallic phases, Tailored forming",
author = "Bernd-Arno Behrens and Johanna Uhe and Tom Petersen and Christian Klose and Susanne Th{\"u}rer and Julian Diefenbach and Anna Chugreeva",
note = "Funding information: This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) grant number 252662854. Acknowledgments: The results presented in this paper were obtained within the Collaborative Research Center 1153 “Process chain to produce hybrid high-performance components by Tailored Forming”—252662854. (subproject B2). The authors would like to thank the German Research Foundation (DFG) for the financial and organizational support of this project. Moreover, the authors wish to express their sincere gratitude to Bettina Niemeyer, Tim Matthias, Anja Krabbenh{\"o}ft and Florian N{\"u}rnberger for their support in performing metallographical, nanoindentation and SEM experiments.",
year = "2021",
month = feb,
day = "8",
doi = "10.3390/ma14040803",
language = "English",
volume = "14",
pages = "1--14",
journal = "MATERIALS",
issn = "1996-1944",
publisher = "MDPI AG",
number = "4",
}