1
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Sun J, Martinsen KH, Klement U, Kovtun A, Xia Z, Silva PF, Hryha E, Nyborg L, Palermo V. Controllable Coating Graphene Oxide and Silanes on Cu Particles as Dual Protection for Anticorrosion. ACS Appl Mater Interfaces 2023; 15:38857-38866. [PMID: 37550051 PMCID: PMC10436246 DOI: 10.1021/acsami.3c08042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023]
Abstract
Although two-dimensional nanosheets like graphene could be ideal atomic coatings to prevent corrosion, it is still controversial whether they are actually effective due to the presence of parasitic effects such as galvanic corrosion. Here, we reported a reduced graphene oxide (RGO) coating strategy to protect sintered Cu metal powders from corrosion by addressing the common galvanic corrosion issue of graphene. A layer of silane molecules, namely, (3-aminopropyl)triethoxysilane (APTES), is deposited between the surface of Cu particles and the graphene oxide (GO), acting as a primer to enhance adhesion and as an insulating interlayer to prevent the direct contact of the Cu with conductive RGO, mitigating the galvanic corrosion. Due to this core-shell coating, the RGO uniformly distributes in the Cu matrix after sintering, avoiding aggregation of RGO, which takes place in conventional GO-Cu composites. The dual coating of GO and silane results in bulk samples with improved anticorrosion properties, as demonstrated by galvanostatic polarization tests using Tafel analysis. Our development not only provides an efficient synthesis method to controllably coat GO on the surface of Cu but also suggests an alternative strategy to avoid the galvanic corrosion effect of graphene to improve the anticorrosion performance of metal.
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Affiliation(s)
- Jinhua Sun
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | - Kristoffer Harr Martinsen
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | - Uta Klement
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | - Alessandro Kovtun
- Institute
of Organic Synthesis and Photoreactivity (ISOF), CNR, via Gobetti 101, Bologna 40129, Italy
| | - Zhenyuan Xia
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | | | - Eduard Hryha
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | - Lars Nyborg
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
| | - Vincenzo Palermo
- Department
of Industrial and Materials Science, Chalmers
University of Technology, Gothenburg SE-41296, Sweden
- Institute
of Organic Synthesis and Photoreactivity (ISOF), CNR, via Gobetti 101, Bologna 40129, Italy
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2
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Raza A, Schwerz C, Pauzon C, Nyborg L, Hryha E. Effect of layer thickness on spatters oxidation of Hastelloy X alloy during powder bed fusion-laser beam processing. POWDER TECHNOL 2023. [DOI: 10.1016/j.powtec.2023.118461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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3
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Schwerz C, Cao Y, Nyborg L. Surface Chemical Analysis of Spatter Particles Generated in Laser Powder Bed Fusion of Hastelloy X in Process Atmospheres with High and Low Oxygen Content. SURF INTERFACE ANAL 2023. [DOI: 10.1002/sia.7202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Claudia Schwerz
- Department of Industrial and Materials Science Chalmers University of Technology SE 412 96 Gothenburg Sweden
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology SE 412 96 Gothenburg Sweden
| | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology SE 412 96 Gothenburg Sweden
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4
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Malladi SBA, Tam PL, Cao Y, Guo S, Nyborg L. Corrosion behaviour of additively manufactured 316L and CoCrNi. SURF INTERFACE ANAL 2023. [DOI: 10.1002/sia.7200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | - Pui Lam Tam
- Department of Industrial and Materials Science Chalmers University of Technology
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology
| | - Sheng Guo
- Department of Industrial and Materials Science Chalmers University of Technology
| | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology
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5
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Martucci A, Tam PL, Aversa A, Lombardi M, Nyborg L. The effect of PBF‐LB/M powder reuse on the surface chemical composition of the Scalmalloy powder. SURF INTERFACE ANAL 2022. [DOI: 10.1002/sia.7176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- A. Martucci
- Department of Applied Science and Technology, Politecnico di Torino Torino Italy
| | - P. L. Tam
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - A. Aversa
- Department of Applied Science and Technology, Politecnico di Torino Torino Italy
| | - M. Lombardi
- Department of Applied Science and Technology, Politecnico di Torino Torino Italy
| | - L. Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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6
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Manchili SK, Liu F, Hryha E, Nyborg L. Carbon-coated iron nanopowder as a sintering aid for water-atomized iron powder. Sci Rep 2022; 12:17850. [PMID: 36284168 PMCID: PMC9596440 DOI: 10.1038/s41598-022-22336-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 10/13/2022] [Indexed: 12/05/2022] Open
Abstract
The paper examines the influence of carbon coating on iron nanopowder used as a sintering aid for water-atomized iron powder. Iron nanopowder without such a coating was used as a reference sintering aid to isolate the influence of the carbon coating. Both nanopowder variants were characterised using XPS and HRTEM. The results showed a core–shell structure for both variants. The iron nanopowder is covered by a 3–4 nm thick iron oxide layer, while the carbon-coated iron nanopowder is encapsulated with several nanometric carbon layers. Thermogravimetry conducted in a pure hydrogen environment shows a multipeak behaviour for the carbon-coated iron nanopowder, while a single peak behaviour is observed for the iron nanopowder. Two types of micro/nanobimodal powders were obtained by mixing the nanopowder with water-atomized iron powder. Improved linear shrinkage was observed during sintering when the carbon-coated iron nanopowder was added. This can be explained by the reduction in surface diffusion in the nanopowder caused by the carbon coating, which allows the nanopowder to sinter at higher temperatures and improves densification. Carbon and oxygen analysis, density measurements, optical microscopy and JMatPro calculations were also performed.
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Affiliation(s)
- Swathi K. Manchili
- grid.5371.00000 0001 0775 6028Department of Industrial and Materials Science, Chalmers University of Technology, 41258 Gothenburg, Sweden ,grid.450308.a0000 0004 0369 268XSIMaP, Grenoble INP, CNRS, Université Grenoble Alpes, Grenoble, France
| | - F. Liu
- grid.5371.00000 0001 0775 6028Department of Industrial and Materials Science, Chalmers University of Technology, 41258 Gothenburg, Sweden
| | - E. Hryha
- grid.5371.00000 0001 0775 6028Department of Industrial and Materials Science, Chalmers University of Technology, 41258 Gothenburg, Sweden
| | - L. Nyborg
- grid.5371.00000 0001 0775 6028Department of Industrial and Materials Science, Chalmers University of Technology, 41258 Gothenburg, Sweden
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7
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Nyborg L, Cao Y. Surface chemical and geometrical properties of pure copper powder intended for binder jetting and sintering. SURF INTERFACE ANAL 2022. [DOI: 10.1002/sia.7107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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Manchili SK, Wendel J, Hryha E, Nyborg L. Sintering of bimodal micrometre/nanometre iron powder compacts - A master sintering curve approach. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.06.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Manchili SK, Wendel J, Cao Y, Hryha E, Nyborg L. Investigation of surface and thermogravimetric characteristics of carbon‐coated iron nanopowder. SURF INTERFACE ANAL 2020. [DOI: 10.1002/sia.6878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Swathi K. Manchili
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Johan Wendel
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Eduard Hryha
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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10
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Affiliation(s)
- Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Mats Delin
- GKN Aerospace Engine Systems Trollhättan Sweden
| | | | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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11
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Riabov D, Hryha E, Rashidi M, Bengtsson S, Nyborg L. Effect of atomization on surface oxide composition in 316L stainless steel powders for additive manufacturing. SURF INTERFACE ANAL 2020. [DOI: 10.1002/sia.6846] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dmitri Riabov
- Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
- Höganäs AB Höganäs Sweden
| | - Eduard Hryha
- Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Masoud Rashidi
- Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
- Mechanical and Aerospace Engineering Nanyang Technological University Singapore
| | | | - Lars Nyborg
- Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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12
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Wendel J, Manchili SK, Cao Y, Hryha E, Nyborg L. Evolution of surface chemistry during sintering of water‐atomized iron and low‐alloyed steel powder. SURF INTERFACE ANAL 2020. [DOI: 10.1002/sia.6852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Johan Wendel
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Swathi K. Manchili
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Eduard Hryha
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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13
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Affiliation(s)
- Eric Bojestig
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Yu Cao
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
| | - Lars Nyborg
- Department of Industrial and Materials Science Chalmers University of Technology Gothenburg Sweden
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Abstract
Abstract
Understanding the effect of powder feedstock alterations during multicycle additive manufacturing on the quality of built components is crucial to meet the requirements on critical parts for aerospace engine applications. In this study, powder recycling of Alloy 718 during electron beam melting was studied to understand its influence on fracture behavior of Charpy impact test bars. High resolution scanning electron microscopy was employed for fracture surface analysis on test bars produced from virgin and recycled powder. For all investigated samples, an intergranular type of fracture, initiated by non-metallic phases and bonding defects, was typically observed in the regions close to or within the contour zone. The fracture mode in the bulk of the samples was mainly moderately ductile dimple fracture. The results show a clear correlation between powder degradation during multi-cycle powder reuse and the amount of damage relevant defects observed on the fracture surfaces. In particular, samples produced from recycled powder show a significant amount of aluminum-rich oxide defects, originating from aluminum-rich oxide particulates on the surface of the recycled powder.
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Affiliation(s)
- H. Gruber
- Department of Industrial and Materials Science, Division of Materials and Manufacture , Chalmers University of Technology , Gothenburg , SE-412 96 , Sweden
| | - P. Karimi
- Department of Engineering Science, Additive Manufacturing Group , University West , SE-46186 Trollhättan , Sweden
| | - E. Hryha
- Department of Industrial and Materials Science, Division of Materials and Manufacture , Chalmers University of Technology , Gothenburg , SE-412 96 , Sweden
| | - L. Nyborg
- Department of Industrial and Materials Science, Division of Materials and Manufacture , Chalmers University of Technology , Gothenburg , SE-412 96 , Sweden
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15
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Affiliation(s)
- J. Wendel
- Chalmers University of Technology; Gothenburg Sweden
| | - R. Shvab
- Chalmers University of Technology; Gothenburg Sweden
| | - Y. Cao
- Chalmers University of Technology; Gothenburg Sweden
| | - E. Hryha
- Chalmers University of Technology; Gothenburg Sweden
| | - L. Nyborg
- Chalmers University of Technology; Gothenburg Sweden
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16
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Affiliation(s)
- Swathi K. Manchili
- Department of Industrial and Materials Science; Chalmers University of Technology; Gothenburg 41956 Sweden
| | - Ruslan Shvab
- Department of Industrial and Materials Science; Chalmers University of Technology; Gothenburg 41956 Sweden
| | - Abdelhafid Zehri
- Department of Microtechnology and Nanoscience; Chalmers University of Technology; Gothenburg 41956 Sweden
| | - Lilei Ye
- SHT Smart High Tech AB; Aschebergsgatan 46 411 33 Gothenburg Sweden
| | - Eduard Hryha
- Department of Industrial and Materials Science; Chalmers University of Technology; Gothenburg 41956 Sweden
| | - Johan Liu
- Department of Microtechnology and Nanoscience; Chalmers University of Technology; Gothenburg 41956 Sweden
| | - Lars Nyborg
- Department of Industrial and Materials Science; Chalmers University of Technology; Gothenburg 41956 Sweden
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17
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Suska F, Kjeller G, Tarnow P, Hryha E, Nyborg L, Snis A, Palmquist A. Electron Beam Melting Manufacturing Technology for Individually Manufactured Jaw Prosthesis: A Case Report. J Oral Maxillofac Surg 2016; 74:1706.e1-1706.e15. [DOI: 10.1016/j.joms.2016.03.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 01/26/2023]
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18
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Oikonomou C, Hryha E, Nyborg L. An XPS investigation on the thermal stability of the insulating surface layer of soft magnetic composite powder. SURF INTERFACE ANAL 2016. [DOI: 10.1002/sia.5993] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- C. Oikonomou
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE-412 96 Gothenburg Sweden
| | - E. Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE-412 96 Gothenburg Sweden
| | - L. Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE-412 96 Gothenburg Sweden
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Weddeling A, Lefor K, Hryha E, Huth S, Nyborg L, Weber S, Theisen W. Nitrogen uptake of nickel free austenitic stainless steel powder during heat treatment-an XPS study. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5730] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Anna Weddeling
- Department of Materials Technology; Ruhr-Universität Bochum; Bochum Germany
| | - Kathrin Lefor
- Department of Materials Technology; Ruhr-Universität Bochum; Bochum Germany
| | - Eduard Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
| | - Stephan Huth
- Department of Materials Technology; Ruhr-Universität Bochum; Bochum Germany
| | - Lars Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
| | - Sebastian Weber
- Department of Novel Manufacturing Technologies and Materials; Bergische Universität Wuppertal; Solingen Germany
| | - Werner Theisen
- Department of Materials Technology; Ruhr-Universität Bochum; Bochum Germany
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20
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Cao Y, Maistro G, Norell M, Pérez‐Garcia SA, Nyborg L. Multi‐technique characterization of low‐temperature plasma nitrided austenitic AISI 304L and AISI 904L stainless steel. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Y. Cao
- Department of Materials and Manufacturing Technology Chalmers University of Technology 41296 Gothenburg Sweden
| | - G. Maistro
- Department of Materials and Manufacturing Technology Chalmers University of Technology 41296 Gothenburg Sweden
| | - M. Norell
- Department of Materials and Manufacturing Technology Chalmers University of Technology 41296 Gothenburg Sweden
| | - S. A. Pérez‐Garcia
- Centro de Investigación en Materiales Avanzados (CIMAV) Unidad Monterrey Alianza Nte. 202 Apodaca Nuevo Leon 66600 Mexico
| | - L. Nyborg
- Department of Materials and Manufacturing Technology Chalmers University of Technology 41296 Gothenburg Sweden
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Oikonomou C, Nikas D, Hryha E, Nyborg L. Evaluation of the thickness and roughness of homogeneous surface layers on spherical and irregular powder particles. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5439] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- C. Oikonomou
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Gothenburg Sweden
| | - D. Nikas
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Gothenburg Sweden
| | - E. Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Gothenburg Sweden
| | - L. Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Gothenburg Sweden
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Hryha E, Rutqvist E, Björkvall J, Nyborg L. Development of methodology for surface characterization of vanadium containing slag. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5363] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- E. Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
| | - E. Rutqvist
- Department of Sales and Marketing; LKAB; Luleå Sweden
| | - J. Björkvall
- Department of Process Metallurgy; Swerea MEFOS; Luleå Sweden
| | - L. Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
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Abstract
Abstract
The processing conditions and the mould design are important parts of the powder injection moulding (PIM) process. In the present work, the mould filling phase of the process has been studied in situ with a special mould equipped with a sight glass using a high speed camera. Effects of features such as the mould temperature, the melt temperature, the surface roughness of the mould cavity, the gate dimensions, the mould design and the flow rate on the filling behaviour were demonstrated. In particular it was noted that a rougher mould surface to some extent facilitated the filling of the mould. The mould temperature, the nominal melt temperature and the flow rate affected the position of weld lines via the cooling of the feedstock and the corresponding change of the melt viscosity. The experimentally determined weld-line positions were compared with predictions from numerical simulations performed with the commercial software Moldex3D. The agreement between the experiment and the prediction was in most cases quite fair or good. The in situ observation of the mould filling also provided the possibility to study how the gate dimensions and the flow rate influenced the jetting behaviour.
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Affiliation(s)
- H. Persson
- Department of Materials and Manufacturing Technology, Chalmers University of Technology, Göteborg, Sweden
| | - M. Jenni
- Advanced Materials, Aerospace Technologies, Austrian Research Centers GmbH, Seibersdorf, Austria
| | - L. Nyborg
- Department of Materials and Manufacturing Technology, Chalmers University of Technology, Göteborg, Sweden
| | - M. Rigdahl
- Department of Materials and Manufacturing Technology, Chalmers University of Technology, Göteborg, Sweden
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Abstract
Abstract
Powder injection moulding (PIM) is an important and accepted industrial technique for net shaping of precision components which can have a rather complex geometry. In order to meet the imposed, often rather strict, requirements with regard to dimensional accuracy, it is important to have an adequate knowledge and control of the rheological behaviour and the related processing properties of the powder/polymer melt (feedstock). Such a knowledge is furthermore of crucial importance in numerical simulations of the PIM-process. In the present work, a model system, consisting of steel powder, poly(ethylene glycol) and wax, is used in order to illustrate how the viscometric properties as well as thermal properties, such as the conductivity and the specific heat, of the system can be related to the corresponding properties of the polymeric binder system. In a similar way, the pvT (pressure-volume-temperature)-behaviour of the model system is analysed and discussed. The pvT-behaviour, which has not been extensively reported on for PIM-feedstocks, is considered to be of significant relevance for controlling the outcome of the injection moulding process.
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Affiliation(s)
- H. Persson
- Chalmers University of Technology, Department of Materials and Manufacturing Technology, Göteborg, Sweden
| | - B. Hausnerová
- Tomas Bata University in Zlin, Polymer Centre, Zlin, Czech Republic
| | - L. Nyborg
- Chalmers University of Technology, Department of Materials and Manufacturing Technology, Göteborg, Sweden
| | - M. Rigdahl
- Chalmers University of Technology, Department of Materials and Manufacturing Technology, Göteborg, Sweden
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25
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Affiliation(s)
- C. Oikonomou
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Göteborg Sweden
| | - E. Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Göteborg Sweden
| | - L. Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; SE - 41296 Göteborg Sweden
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26
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Affiliation(s)
- E. Hryha
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
| | | | - L. Nyborg
- Department of Materials and Manufacturing Technology; Chalmers University of Technology; Gothenburg Sweden
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Milleding P, Karlsson S, Nyborg L. On the surface elemental composition of non-corroded and corroded dental ceramic materials in vitro. J Mater Sci Mater Med 2003; 14:557-566. [PMID: 15348440 DOI: 10.1023/a:1023416232222] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Dental ceramics are traditionally looked upon as inert materials. As many are glass phased, it may be hypothesized that they will be subjected to glass corrosion in aqueous environments. The aim of the study was therefore to analyze the surface elemental composition of glass-phased and all-crystalline ceramics, before and after low- and high-intensity, in vitro corrosion (milli-Q-water at 37+/-2 degrees C for 18 h and 4% acetic acid at 80+/-2 degrees C for 18 h, respectively). The analysis of the surface elemental composition was performed using ESCA. The hypothesis was confirmed. After high-intensity corrosion, the complete wash out of alkali ions, alkaline-earth ions and elemental alumina was found, leaving behind a surface totally dominated by silica. The all-crystalline ceramics, densely sintered alumina and yttria-partially stabilized tetragonal zirconia, displayed only minor surface changes, even after high-intensity corrosion. In comparison to the corrosion testing in acid, the corrosion process in milli-Q-water did not produce different results in principle, except for the lower magnitude of the depletion of alkali ions and the virtually unchanged level of elemental alumina. Unexpectedly, no substantial difference in surface degradation was found between the glass ceramic and the ordinary porcelain-fused-to-metal ceramic or between ceramics of higher sintering temperature and those of low or ultra-low sintering temperature. The composition and microstructure alone did not appear to provide a full explanation for the inter-individual differences in surface corrosion when exposed to comparable environmental conditions.
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Affiliation(s)
- P Milleding
- Department of Prosthetic Dentistry/Dental Materials Science, Faculty of Odontology, Göteborg University, Box 450, SE-405 30 Göteborg, Sweden.
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Johansson E, Nyborg L. XPS study of carboxylic acid layers on oxidized metals with reference to particulate materials. SURF INTERFACE ANAL 2003. [DOI: 10.1002/sia.1537] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Lundin J, Holmlid L, Menon PG, Nyborg L. Surface composition of iron oxide catalysts used for styrene production: an Auger electron spectroscopy/scanning electron microscopy study. Ind Eng Chem Res 2002. [DOI: 10.1021/ie00023a010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Asteman H, Norling R, Svensson JE, Nylund A, Nyborg L. Quantitative AES depth profiling of iron and chromium oxides in solid solution, (Cr1?xFex)2O3. SURF INTERFACE ANAL 2002. [DOI: 10.1002/sia.1290] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Mogensen PK, Møller J, Nyborg L, Magid E, Wimmelmann N, Uldall A. Calibration of the Ektachem Amylase method using human reference materials and the Phadebas Blue Starch method as an interim reference method. Scand J Clin Lab Invest 1996; 56:505-9. [PMID: 8903112 DOI: 10.3109/00365519609088806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In a multilaboratory study a consensus was established to calibrate the Ektachem Amylase method to reproduce the results of the Phadebas Blue Starch method. The calibration graph has a slope = 3.39 and intercept = 25. For the Ektachem Amylase method the reaction-rate ratio between salivary and pancreatic amylase was calculated to be 0.89, relative to that of the Phadebas Blue Starch method. A calibration value for the Nordic Amylase Calibrator to be used on Ektachem analysers was determined to be close to 469 U l-1 for the current batch. However, since the difference from the stated value of 460 U l-1 is negligible, the authors recommend the use of the stated value for this and future batches of the Nordic Amylase Calibrator. An error of around 10% introduced by the presence of salivary amylase is comparable to the methods accepted by the Scandinavian Committee on Enzymes. Introduction of a consensus calibration reduced the interlaboratory variation by up to 40% at all levels.
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Affiliation(s)
- P K Mogensen
- Department of Clinical Chemistry, Herning Centralsygehus, Denmark
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Norell M, Nyborg L, Tunberg T, Olefjord I. Thickness determination of surface oxides on metal powder by AES depth profiling. SURF INTERFACE ANAL 1992. [DOI: 10.1002/sia.740190116] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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