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Berglund, J., Holmberg, J., Wärmefjord, K. & Söderberg, R. (2024). Detailed evaluation of topographical effects of Hirtisation post-processing on electron beam powder bed fusion (PBF-EB) manufactured Ti-6Al-4V component. Precision engineering, 85, 319-327
Open this publication in new window or tab >>Detailed evaluation of topographical effects of Hirtisation post-processing on electron beam powder bed fusion (PBF-EB) manufactured Ti-6Al-4V component
2024 (English)In: Precision engineering, ISSN 0141-6359, E-ISSN 1873-2372, Vol. 85, p. 319-327Article in journal (Refereed) Published
Abstract [en]

Metal additive manufacturing surface topographies are complex and challenging to characterise due to e.g. steep local slopes, re-entrant features, varying reflectivity and features of interest in vastly different scale ranges. Nevertheless, average height parameters such as Ra or Sa are commonly used as sole parameters for characterisation. In this paper, a novel method for selecting relevant parameters for evaluation is proposed and demonstrated using a case study where the smoothing effects after three processing steps of the electro chemical post-process Hirtisation of a metal AM surface are quantified. The method uses a combination of conventional areal texture parameters, multiscale analysis and statistics and can be used to efficiently achieve a detailed and more relevant surface topography characterisation. It was found that the three process steps have different effects on the surface topography regarding the types and sizes of features that were affected. In total, Sdq was reduced by 97 %, S5v was reduced by 81 % and Sa was reduced by 78 %. A surface texture with much lower average roughness, less deep pits and less steep slopes was produced, which is expected to be beneficial for improved fatigue properties.

Place, publisher, year, edition, pages
Elsevier Inc., 2024
Keywords
Aluminum alloys; Textures; Titanium alloys; Topography; Average height; Electron-beam; Hirtisation; Metal additives; Multi scale analysis; PBF-EB/M/ti6al4v; Post-processing; Powder bed; Surface topography characterization; Topographical effects; Surface topography
National Category
Materials Engineering
Identifiers
urn:nbn:se:ri:diva-67955 (URN)10.1016/j.precisioneng.2023.10.007 (DOI)2-s2.0-85175704403 (Scopus ID)
Note

J.B. is grateful for the support from Vinnova, the Swedish Innovation Agency, by means of grant 2022-03111 . This research did not receive any other specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Available from: 2023-11-27 Created: 2023-11-27 Last updated: 2023-11-27Bibliographically approved
Holmberg, J., Berglund, J., Stormvinter, A., Andersson, P. & Lundin, P. (2023). Influence of Local Electropolishing Conditions on Ferritic–Pearlitic Steel on X-Ray Diffraction Residual Stress Profiling. Journal of materials engineering and performance (Print)
Open this publication in new window or tab >>Influence of Local Electropolishing Conditions on Ferritic–Pearlitic Steel on X-Ray Diffraction Residual Stress Profiling
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2023 (English)In: Journal of materials engineering and performance (Print), ISSN 1059-9495, E-ISSN 1544-1024Article in journal (Refereed) Epub ahead of print
Abstract [en]

Layer removal with electropolishing is a well-established method when measuring residual stress profiles with lab-XRD. This is done to measure the depth impact from processes such as shot peening, heat treatment, or machining. Electropolishing is used to minimize the influence on the inherent residual stresses of the material during layer removal, performed successively in incremental steps to specific depths followed by measurement. Great control of the material removal is critical for the measured stresses at each depth. Therefore, the selection of size of the measurement spot and electropolishing parameters is essential. The main objective in this work is to investigate how different electrolytes and electropolishing equipment affect the resulting surface roughness, geometry, microstructure, and consequently the measured residual stress. A second objective has been to establish a methodology of assessing the acquired electropolished depth. The aim has been to get a better understanding of the influence of the layer removal method on the accuracy of the acquired depth. Evaluation has been done by electropolishing one ground and one shot peened sample of a low-alloy carbon steel, grade 1.1730, with different methods. The results showed a difference in stresses depending on the electrolyte used where the perchloric acid had better ability to retain the stresses compared to the saturated salt. Electropolishing with saturated salt is fast and results in evenly distributed material removal but has high surface roughness, which is due to a difference in electropolishing of the two phases, ferrite, and pearlite. Perchloric acid electropolishing is slower but generates a smooth surface as both ferrite and pearlite have the same material removal rates but may cause an increased material removal for the center of the electropolished area. In this work, it is suggested to use perchloric acid electropolishing for the final layer removal step. © 2023, The Author(s).

Place, publisher, year, edition, pages
Springer, 2023
Keywords
electrolytical polishing, perchloric acid, profile, residual stress, saturated salt, Electrolytes, Electrolytic polishing, Ferrite, Pearlite, Salt removal, Shot peening, Surface roughness, Condition, Electropolished, Ferritic, Layer removal, Material removal, Pearlitic steels, Perchloric acids, Saturated salts, Residual stresses
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:ri:diva-65665 (URN)10.1007/s11665-023-08525-w (DOI)2-s2.0-85165702085 (Scopus ID)
Note

Correspondence Address: J. Holmberg; RISE Research Institutes of Sweden AB, Gothenburg, Sweden; email: jonas.holmberg@ri.se; 

The authors would like to thank RISE Research Institutes of Sweden AB and Stresstech OY for the support of this study.

Available from: 2023-08-09 Created: 2023-08-09 Last updated: 2024-02-27Bibliographically approved
Holmberg, J., Berglund, J., Brohede, U., Åkerfeldt, P., Sandell, V., Rashid, A., . . . Hosseini, S. (2023). Machining of additively manufactured alloy 718 in as-built and heat-treated condition: surface integrity and cutting tool wear. The International Journal of Advanced Manufacturing Technology, 130(3-4), 1823-1842
Open this publication in new window or tab >>Machining of additively manufactured alloy 718 in as-built and heat-treated condition: surface integrity and cutting tool wear
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2023 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 130, no 3-4, p. 1823-1842Article in journal (Refereed) Published
Abstract [en]

Additive manufacturing (AM) using powder bed fusion is becoming a mature technology that offers great possibilities and design freedom for manufacturing of near net shape components. However, for many gas turbine and aerospace applications, machining is still required, which motivates further research on the machinability and work piece integrity of additive-manufactured superalloys. In this work, turning tests have been performed on components made with both Powder Bed Fusion for Laser Beam (PBF-LB) and Electron Beam (PBF-EB) in as-built and heat-treated conditions. The two AM processes and the respective heat-treatments have generated different microstructural features that have a great impact on both the tool wear and the work piece surface integrity. The results show that the PBF-EB components have relatively lower geometrical accuracy, a rough surface topography, a coarse microstructure with hard precipitates and low residual stresses after printing. Turning of the PBF-EB material results in high cutting tool wear, which induces moderate tensile surface stresses that are balanced by deep compressive stresses and a superficial deformed surface that is greater for the heat-treated material. In comparison, the PBF-LB components have a higher geometrical accuracy, a relatively smooth topography and a fine microstructure, but with high tensile stresses after printing. Machining of PBF-LB material resulted in higher tool wear for the heat-treated material, increase of 49%, and significantly higher tensile surface stresses followed by shallower compressive stresses below the surface compared to the PBF-EB materials, but with no superficially deformed surface. It is further observed an 87% higher tool wear for PBF-EB in as-built condition and 43% in the heat-treated condition compared to the PBF-LB material. These results show that the selection of cutting tools and cutting settings are critical, which requires the development of suitable machining parameters that are designed for the microstructure of the material.

Place, publisher, year, edition, pages
Springer Science and Business Media Deutschland GmbH, 2023
Keywords
3D printing; Additives; Aerospace applications; Compressive stress; Cutting tools; Microstructure; Surface stress; Topography; Turning; Wear of materials; Alloy 718; Beam components; Beam material; Electron-beam; Geometrical accuracy; Heat treated condition; Powder bed; Surface integrity; Tensile surface stress; Tool wear; Laser beams
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-68829 (URN)10.1007/s00170-023-12727-w (DOI)2-s2.0-85179663025 (Scopus ID)
Funder
Vinnova, 2016–05175Swedish Foundation for Strategic Research, GMT14-048Swedish Research Council, 2016–05460
Note

Open access funding provided by RISE Research Institutes of Sweden. This research has been funded by the Swedish Arena for Additive Manufacturing and Vinnova through grant ref no. 2016–05175. The researchers at Uppsala acknowledge the Swedish Foundation for Strategic Research (SSF) project GMT14-048 (Additive Manufacturing—Development of Process and Materials) and the Swedish Research Council, grant 2016–05460, for financial support.

Available from: 2024-01-08 Created: 2024-01-08 Last updated: 2024-01-08Bibliographically approved
Akbari, S., Holmberg, J., Andersson, D., Mishra, M. & Brinkfeldt, K. (2023). Packaging Induced Stresses in Embedded and Molded GaN Power Electronics Components. In: Int. Conf. Therm., Mech. Multi-Phys. Simul. Exp. Microelectron. Microsyst., EuroSimE: . Paper presented at 2023 24th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2023. Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Packaging Induced Stresses in Embedded and Molded GaN Power Electronics Components
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2023 (English)In: Int. Conf. Therm., Mech. Multi-Phys. Simul. Exp. Microelectron. Microsyst., EuroSimE, Institute of Electrical and Electronics Engineers Inc. , 2023Conference paper, Published paper (Refereed)
Abstract [en]

Residual stresses created during the packaging process can adversely affect the reliability of electronics components. We used incremental hole-drilling method, following the ASTM E 837-20 standard, to measure packaging induced residual stresses in discrete packages of power electronics components. For this purpose, we bonded a strain gauge on the surface of a Gallium Nitride (GaN) power component, drilled a hole through the thickness of the component in several incremental steps, recorded the relaxed strain data on the sample surface using the strain gauge, and finally calculated the residual stresses from the measured strain data. The recorded strains and the residual stresses are related by the compliance coefficients. For the hole drilling method in the isotropic materials, the compliance coefficients are calculated from the analytical solutions, and available in the ASTM standard. But for the orthotropic multilayered components typically found in microelectronics assemblies, numerical solutions are necessary. We developed a subroutine in ANSYS APDL to calculate the compliance coefficients of the hole drilling test in the molded and embedded power electronics components. This can extend the capability of the hole drilling method to determine residual stresses in more complex layered structures found in electronics. 

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2023
Keywords
ASTM standards, Elasticity, Gallium nitride, III-V semiconductors, Microelectronics, Strain, Strain gages, Structural design, Discrete package, Electronic component, Incremental hole drilling method, Packaging induced stress, Packaging process, Power components, Power electronic components, Strain data, Strain-gages, Residual stresses
National Category
Applied Mechanics
Identifiers
urn:nbn:se:ri:diva-65629 (URN)10.1109/EuroSimE56861.2023.10100830 (DOI)2-s2.0-85158147217 (Scopus ID)
Conference
2023 24th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2023
Note

 Correspondence Address: S. Akbari; Rise Research Institutes of Sweden, Sweden; This project has received funding from European Union s Horizon 2020 research and innovation programme (UltimateGaN project, grant agreement No 826392). It was also supported by Future Power Electronics Project funded by the ICT- Sweden.

Available from: 2023-06-30 Created: 2023-06-30 Last updated: 2023-10-30Bibliographically approved
Holmberg, J., Hammersberg, P., Lundin, P. & Olavison, J. (2023). Predictive Modeling of Induction-Hardened Depth Based on the Barkhausen Noise Signal. Micromachines, 14(1)
Open this publication in new window or tab >>Predictive Modeling of Induction-Hardened Depth Based on the Barkhausen Noise Signal
2023 (English)In: Micromachines, E-ISSN 2072-666X, Vol. 14, no 1Article in journal (Refereed) Published
Abstract [en]

A non-destructive verification method was explored in this work using the Barkhausen noise (BN) method for induction hardening depth measurements. The motive was to investigate the correlation between the hardness depth, microstructure, and the Barkhausen noise signal for an induction hardening process. Steel samples of grade C45 were induction-hardened to generate different hardness depths. Two sets of samples were produced in two different induction hardening equipment for generating the model and verification. The produced samples were evaluated by BN measurements followed by destructive verification of the material properties. The results show great potential for the several BN parameters, especially the magnetic voltage sweep slope signal, which has strong correlation with the hardening depth to depth of 4.5 mm. These results were further used to develop a multivariate predictive model to assess the hardness depth to 7 mm, which was validated on an additional dataset that was holdout from the model training.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
Barkhausen noise, induction hardening, predictive modeling
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-62458 (URN)10.3390/mi14010097 (DOI)
Note

This research was funded by Vinnova, the Swedish government agency within Ministry of Enterprise, grant number [2015-03721].

Available from: 2023-01-24 Created: 2023-01-24 Last updated: 2024-01-17Bibliographically approved
Holmberg, J., Wretland, A. & Berglund, J. (2022). Abrasive Water Jet Milling as An Efficient Manufacturing Method for Superalloy Gas Turbine Components. Journal of Manufacturing and Materials Processing, 6(5), Article ID 124.
Open this publication in new window or tab >>Abrasive Water Jet Milling as An Efficient Manufacturing Method for Superalloy Gas Turbine Components
2022 (English)In: Journal of Manufacturing and Materials Processing, ISSN 2504-4494, Vol. 6, no 5, article id 124Article in journal (Refereed) Published
Abstract [en]

In order to improve efficiency when manufacturing gas turbine components, alternative machining techniques need to be explored. In this work, abrasive water jet (AWJ) machining by milling has been investigated as an alternative to traditional milling. Various test campaigns have been conducted to show different aspects of using AWJ milling for the machining of superalloys, such as alloy 718. The test campaigns span from studies of individual AWJ-milled tracks, multi-pass tracks, and the machining of larger components and features with complex geometry. In regard to material removal rates, these studies show that AWJ milling is able to compete with traditional semi/finish milling but may not reach as high an MRR as rough milling when machining in alloy 718. However, AWJ milling requires post-processing which decreases the total MRR. It has been shown that a strong advantage with AWJ milling is to manufacture difficult geometries such as narrow radii, holes, or sharp transitions with kept material removal rates and low impact on the surface integrity of the cut surface. Additionally, abrasive water jet machining (AWJM) offers a range of machining possibilities as it can alter between cutting through and milling. The surface integrity of the AWJM surface is also advantageous as it introduces compressive residual stress but may require post-processing to meet similar surface roughness levels as traditional milling and to remove unwanted AWJM particles from the machined surface. © 2022 by the authors.

Place, publisher, year, edition, pages
MDPI, 2022
Keywords
abrasive water jet machining, alloy 718, milling, superalloys, surface integrity
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-61207 (URN)10.3390/jmmp6050124 (DOI)2-s2.0-85140576201 (Scopus ID)
Note

Funding details: 2015-06047, 2017-05589; Funding details: VINNOVA; Funding text 1: This research was funded by Vinnova, the Swedish government agency within Ministry of Enterprise, grant number grant number [2015-06047] and grant number [2017-05589].

Available from: 2022-12-06 Created: 2022-12-06 Last updated: 2023-05-22Bibliographically approved
Hosseini, S., Mallipeddi, D., Holmberg, J., Rännar, L.-E. -., Koptyug, A., Sjöström, W., . . . Klement, U. (2022). Comparison of machining performance of stainless steel 316L produced by selective laser melting and electron beam melting. In: Procedia CIRP: . Paper presented at 10th CIRP Global Web Conference on Material Aspects of Manufacturing Processes, 25 October 2022 through 27 October 2022 (pp. 72-77). Elsevier B.V.
Open this publication in new window or tab >>Comparison of machining performance of stainless steel 316L produced by selective laser melting and electron beam melting
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2022 (English)In: Procedia CIRP, Elsevier B.V. , 2022, p. 72-77Conference paper, Published paper (Refereed)
Abstract [en]

Powder bed fusion processes based additively manufactured SS 316L components fall short of surface integrity requirements needed for optimal functional performance. Hence, machining is required to achieve dimensional accuracy and to enhance surface integrity characteristics. This research is focused on comparing the material removal performance of 316L produced by PBF-LB (laser) and PBF-EB (electron beam) in terms of tool wear and surface integrity. The results showed comparable surface topography and residual stress profiles. While the hardness profiles revealed work hardening at the surface where PBF-LB specimens being more susceptible to work hardening. The investigation also revealed differences in the progress of the tool wear when machining specimens produced with either PBF-LB or PBF-EB. .

Place, publisher, year, edition, pages
Elsevier B.V., 2022
Keywords
Additive manufacturing, electron beam melting, machining, selective laser melting, surface integrity, Additives, Austenitic stainless steel, Cutting tools, Electron beams, Strain hardening, Wear of materials, Electron-beam melting, Fusion process, Machining performance, Powder bed, Process-based, SS 316L, Stainless steel (316L), Tool wear, Topography
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-62606 (URN)10.1016/j.procir.2022.10.052 (DOI)2-s2.0-85145230165 (Scopus ID)
Conference
10th CIRP Global Web Conference on Material Aspects of Manufacturing Processes, 25 October 2022 through 27 October 2022
Note

Funding text 1: Amir-Reza Shahab is acknowledged for initial work. This study is a collaboration between RISE AB, the Centre for Metal Cutting Research and the Centre for Additive Manufacture – Metal at Chalmers University of Technology, and Mid Sweden University. We thank Swedish oG vernmental Agency of Innovation Systems (Vinnova 2016-05175) for funding. Rolf Ahlman at RISE AB and Dr. Sinuhe at Sandvik Coromant are thanked for their support with turning tests and providing the respective machining tools.

Available from: 2023-01-24 Created: 2023-01-24 Last updated: 2023-06-08Bibliographically approved
Kokkirala, S., Holmberg, J., Klement, U., Lundström, R., Iwasaki, H. & Hosseini, S. (2022). Effect of cutting parameters on the generated surface integrity of hard-turned martensitic AISI 52100 bearing steel. In: Procedia CIRP: . Paper presented at 10th CIRP Global Web Conference on Material Aspects of Manufacturing Processes, 25 October 2022 through 27 October 2022 (pp. 154-159). Elsevier B.V.
Open this publication in new window or tab >>Effect of cutting parameters on the generated surface integrity of hard-turned martensitic AISI 52100 bearing steel
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2022 (English)In: Procedia CIRP, Elsevier B.V. , 2022, p. 154-159Conference paper, Published paper (Refereed)
Abstract [en]

Hard turning offers improved manufacturing efficiency but requires great control of the cutting process to achieve the required machining-induced surface integrity with respect to residual stresses, surface topography, and near-surface microstructure. This research work is focused on studying the effect of the cutting speed, feed rate, depth of cut, chamfer angle, and coolant pressure on the surface integrity after hard turning of martensitic AISI 52100 steel. The results showed that the feed rate had a significant influence on the residual stresses and the surface topography. The discontinuous mechanically induced white layer was observed at high cutting speed and high chamfer angle with increased thickness. 

Place, publisher, year, edition, pages
Elsevier B.V., 2022
Keywords
Hard turning, residual stress, surface integrity, surface topography, white layer, Cutting, Topography, Turning, Bearing steels, Cutting parameters, Cutting process, Cutting speed, Feedrate, Manufacturing efficiency, Martensitics, Residual stresses
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-62607 (URN)10.1016/j.procir.2022.10.066 (DOI)2-s2.0-85145228748 (Scopus ID)
Conference
10th CIRP Global Web Conference on Material Aspects of Manufacturing Processes, 25 October 2022 through 27 October 2022
Note

Funding text 1: This work is part of the project Turn2Flex ( iV nnova 2021 - 01274) financed by the Swedish government agency for Enterprise and Innovation. Special thanks to AB SKF, Sumitomo Hartmetall Electric GmbH , and Ovako AB for support of material and manufacturing of samples. Thanks to Dr. Yiming Yao for support with the SEM analy sis. We also thank Thord Johansson and Dr. Thomas Bjrö k for the valuable discussion and support.

Available from: 2023-01-24 Created: 2023-01-24 Last updated: 2023-05-22Bibliographically approved
Götelid, S., Ma, T., Lyphout, C., Vang, J., Stålnacke, E., Holmberg, J., . . . Strondl, A. (2021). Effect of post-processing on microstructure and mechanical properties of Alloy 718 fabricated using powder bed fusion additive manufacturing processes. Rapid prototyping journal, 27(9), 1617-1632
Open this publication in new window or tab >>Effect of post-processing on microstructure and mechanical properties of Alloy 718 fabricated using powder bed fusion additive manufacturing processes
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2021 (English)In: Rapid prototyping journal, ISSN 1355-2546, E-ISSN 1758-7670, Vol. 27, no 9, p. 1617-1632Article in journal (Refereed) Published
Abstract [en]

Purpose: This study aims to investigate additive manufacturing of nickel-based superalloy IN718 made by powder bed fusion processes: powder bed fusion laser beam (PBF-LB) and powder bed fusion electron beam (PBF-EB). Design/methodology/approach: This work has focused on the influence of building methods and post-fabrication processes on the final part properties, including microstructure, surface quality, residual stresses and mechanical properties. Findings: PBF-LB produced a much smoother surface. Blasting and shot peening (SP) reduced the roughness even more but did not affect the PBF-EB surface finish as much. As-printed PBF-EB parts have low residual stresses in all directions, whereas it was much higher for PBF-LB. However, heat treatment removed the stresses and SP created compressive stresses for samples from both PBF processes. The standard Arcam process parameter for PBF-EB for IN718 is not fully optimized, which leads to porosity and inferior mechanical properties. However, impact toughness after hot isostatic pressing was surprisingly high. Originality/value: The two processes gave different results and also responses to post-treatments, which could be of advantage or disadvantage for different applications. Suggestions for improving the properties of parts produced by each method are presented.

Place, publisher, year, edition, pages
Emerald Group Holdings Ltd., 2021
Keywords
Alloy 718, Hot isostatic pressing (HIP), Mechanical properties, Powder bed fusion electron beam (PBF-EB), Powder bed fusion laser beam (PBF-LB), Residual stress, 3D printers, Additives, Fabrication, Heat treatment, Hot isostatic pressing, Laser beams, Microstructure, Nickel alloys, Residual stresses, Shot peening, Additive manufacturing process, Building methods, Design/methodology/approach, Microstructure and mechanical properties, Nickel- based superalloys, Post-fabrication, Process parameters, Surface finishes
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-56709 (URN)10.1108/RPJ-12-2019-0310 (DOI)2-s2.0-85115084872 (Scopus ID)
Available from: 2021-10-04 Created: 2021-10-04 Last updated: 2023-06-08Bibliographically approved
Holmberg, J., Wretland, A., Berglund, J., Beno, T. & Karlsson, A. (2021). Surface integrity investigation to determine rough milling effects for assessment of machining allowance for subsequent finish milling of alloy 718. Journal of Manufacturing and Materials Processing, 5(2), Article ID 48.
Open this publication in new window or tab >>Surface integrity investigation to determine rough milling effects for assessment of machining allowance for subsequent finish milling of alloy 718
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2021 (English)In: Journal of Manufacturing and Materials Processing, ISSN 2504-4494, Vol. 5, no 2, article id 48Article in journal (Refereed) Published
Abstract [en]

The planned material volume to be removed from a blank to create the final shape of a part is commonly referred to as allowance. Determination of machining allowance is essential and has a great impact on productivity. The objective of the present work is to use a case study to investigate how a prior rough milling operation affects the finish machined surface and, after that, to use this knowledge to design a methodology for how to assess the machining allowance for subsequent milling operations based on residual stresses. Subsequent milling operations were performed to study the final surface integrity across a milled slot. This was done by rough ceramic milling followed by finish milling in seven subsequent steps. The results show that the up-, centre and down-milling induce different stresses and impact depths. Employing the developed methodology, the depth where the directional influence of the milling process diminishes has been shown to be a suitable minimum limit for the allowance. At this depth, the plastic flow causing severe deformation is not present anymore. It was shown that the centre of the milled slot has the deepest impact depth of 500 µm, up-milling caused an intermediate impact depth of 400 µm followed by down milling with an impact depth of 300 µm. With merged envelope profiles, it was shown that the effects from rough ceramic milling are gone after 3 finish milling passes, with a total depth of cut of 150 µm. © 2021 by the authors. 

Place, publisher, year, edition, pages
MDPI AG, 2021
Keywords
Alloy 718, High volumetric milling, Machining allowance determination, Material removal rate, Residual stresses, Surface integrity
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:ri:diva-53491 (URN)10.3390/jmmp5020048 (DOI)2-s2.0-85106944788 (Scopus ID)
Note

Funding details: VINNOVA, 2018-02976; Funding text 1: Funding: This research was funded by VINNOVA, Sweden’s innovation agency, with grant number [2018-02976].; Funding text 2: Acknowledgments: Thanks for the financed by VINNOVA, Sweden’s innovation agency. Special thanks to GKN Aerospace Sweden AB and Tooltec Trestad AB. The authors also would like to thank the KK-foundation and the SiCoMaP research school.

Available from: 2021-06-08 Created: 2021-06-08 Last updated: 2023-05-22Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2991-2911

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