Surface integrity on post processed alloy 718 after non-conventional machining

113 Pages·2017·28.67 MB·English

J Licentiate Thesis
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S 2018 No. 20
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Surface integrity on post processed alloy 718 M
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after non-conventional machining G
Surface integrity on post processed
Alternative production technologies emerges on the market that may contribute of making
the production of aero engine components of superalloys even more efficient than it is today. alloy 718 after non-conventional
Introducing new and non-conventional machining technologies allows taking a giant leap to
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increase the material removal rate and thereby drastically increase the productivity. However, OU
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the end result is to meet the requirements set for today’s machined surfaces. CA
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The present work has been dedicated to improving the knowledge of how the non-convention- VEN INT
al machining methods Abrasive Water Jet Machining, AWJM, Laser Beam Machining, LBM, TIOEGR
and Electrical Discharge Machining, EDM, affect the surface integrity. The aim has been to NAL MITY O
understand how the surface integrity could be altered to an acceptable level. The results of this ACN P Jonas Holmberg
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work have shown that both EDM and AWJM are two possible candidates but EDM is the better INST
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alternative; mainly due to the method’s ability to machine complex geometries. It has further GR
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been shown that both methods require post processing in order to clean the surface and to E
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improve the topography and for the case of EDM a generation of compressive residual stresses E
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are also needed. AL
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Three cold working post processes have been evaluated in order to attain this: shot peening, 7
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grit blasting and high pressure water jet cleaning, HPWJC. The results showed that a combi- A
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nation of two post processes is required in order to reach the specified level of surface integrity TE
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in terms of cleaning and generating compressive residual stresses and low surface roughness.
The method of high pressure water jet cleaning was the most effective method for removing
the EDM wire residuals, and shot peening generated the highest compressive residual stresses
as well as improved the surface topography.
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ISBN 978-91-87531-72-9 (Print) O
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ISBN 978-91-87531-71-2 (PDF) 0

Tryck: BrandFactory, februari 2018.
Licentiate Thesis
Production Technology
2018 No. 20
Surface integrity on post processed
alloy 718 after non-conventional
machining
Jonas Holmberg
University West
SE-46186 Trollhättan
Sweden
[phone]
www.hv.se

© Jonas Holmberg, 2018
ISBN 978-91-87531-72-9 (Printed version)
978-91-87531-71-2 (Electronic version)

Mölndal, Sweden, 2018
To my near and dear

Acknowledgements
First of all I want to dedicate my warm gratitude for the guidance and support
to my two industrial supervisors Dr. Johan Berglund at Swerea IVF and MSc.
Anders Wretland at GKN, without your support this work would not been
carried out. I would also like to acknowledge the academic support from
supervisor Professor Tomas Beno.
The majority of the results in this thesis work have been part of the research
projects G5Demo-2 and Swedemo funded by VINNOVA, the Swedish
Government agency within the Ministry of Enterprise which I would like to
acknowledge.
I also would like to thank Swerea IVF and a special thanks to my colleagues at
the Department of Manufacturing for their support.
Special thanks to GKN Aerospace Sweden AB for supplying test materials,
information and expertise in the involved processes.
I also would like to acknowledge the collaboration work with Mr. Alfredo
Suárez at Tecnalia for inviting me to their projecvt and for the work with the
joint publication.
Further, I would like to thank University West for the support and giving me
the opportunity to perform this PhD work and further the KK-foundation and
the SiCoMap+ research school for all support.
Finally, I would like to send the deepest gratitude to my beautiful family for
having the patient with me and that I can always rely on your total support, love
you all.

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