Change search
Link to record
Permanent link

Direct link
BETA
Vilardell, Anna M.
Publications (5 of 5) Show all publications
Vilardell, A. M., Fredriksson, G., Yadroitsev, I. & Krakhmalev, P. (2019). Fracture mechanisms in the as-built and stress-relieved laser powder bed fusion Ti6Al4V ELI alloy. Optics and Laser Technology, 109, 608-615
Open this publication in new window or tab >>Fracture mechanisms in the as-built and stress-relieved laser powder bed fusion Ti6Al4V ELI alloy
2019 (English)In: Optics and Laser Technology, ISSN 0030-3992, E-ISSN 1879-2545, Vol. 109, p. 608-615Article in journal (Refereed) Published
Abstract [en]

The influence of a stress-relief treatment on impact and fatigue properties of Ti6Al4V ELI samples manufactured by laser powder bed fusion was analyzed. The heat treatment resulted in removal of residual stresses, coarsening of needles and formation of precipitations between needles. In both, impact and fatigue tests, crack development was correlated to microstructural features. Fracture analysis was carried out by means of optical and electron microscopy to reveal the influence of microstructure on crack development. Ductile fracture was the dominating fracture mode at impact testing. Pore formation and coalescence were the main crack formation mechanisms. The microstructural changes led to a decrease in impact toughness after heat treatment. Presumably, this was a result of the precipitations between needles. Fatigue results showed multiple crack nucleation at the surface in both, as-built and stress-relieved material. The crack propagation rate was slightly higher and the crack was less deflected in the stress-relieved material due to the stress relief and coarsening of the microstructure.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Fracture analysis, Impact and fatigue properties, Laser powder bed fusion, Stress-relief treatment, Ti6A4V ELI, Aluminum alloys, Coarsening, Cracks, Ductile fracture, Fatigue testing, Fracture testing, Heat treatment, Impact testing, Microstructural evolution, Needles, Residual stresses, Stress relief, Titanium alloys, Crack propagation rate, Laser powders, Microstructural changes, Microstructural features, Optical and electron microscopies, Fatigue of materials
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-69444 (URN)10.1016/j.optlastec.2018.08.042 (DOI)000446949600074 ()2-s2.0-85053287726 (Scopus ID)
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2019-01-31Bibliographically approved
Vilardell, A. M., Cinca, N., Cano, I. G., Concustell, A., Dosta, S., Guilemany, J. M., . . . Peiro, F. (2017). Dense nanostructured calcium phosphate coating on titanium by cold spray. Journal of the European Ceramic Society, 37(4), 1747-1755
Open this publication in new window or tab >>Dense nanostructured calcium phosphate coating on titanium by cold spray
Show others...
2017 (English)In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 37, no 4, p. 1747-1755Article in journal (Refereed) Published
Abstract [en]

This article deals with the understanding of building-up mechanisms of bioactive nanocrystalline hydroxyapatite coatings by Cold Spray, revealing very promising results in contrast to more conventional techniques such as Plasma Spray. A full characterization of feedstock and coatings is provided. The agglomerated structure of the powder proved to be suitable to obtain successfully thick hydroxyapatite coatings. A crystallite size below similar to 20 nm in the powder and the as-sprayed coatings is calculated by the Rietveld X-ray refinement method and agreed by Transmission Electron Microscopy. Some wipe tests were carried out on Ti6Al4V substrates in order to study the deposition of single particles and the nanoscale features were evaluated. The resulting structure indicates that there is no delimitation of particle boundaries and the overall coating has been formed by effective compaction of the original nanocrystallites, leading to consistent and consolidated layers. (C) 2016 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Coating, Nanocrystalline calcium phosphate, Cold spray, Electron microscopy
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-65097 (URN)10.1016/j.jeurceramsoc.2016.11.040 (DOI)000394482700065 ()
Available from: 2017-11-17 Created: 2017-11-17 Last updated: 2019-05-27Bibliographically approved
Cinca, N., Vilardell, A. M., Dosta, S., Concustell, A., Garcia Cano, I., Maria Guilemany, J., . . . Peiro, F. (2016). A New Alternative for Obtaining Nanocrystalline Bioactive Coatings: Study of Hydroxyapatite Deposition Mechanisms by Cold Gas Spraying. Journal of The American Ceramic Society, 99(4), 1420-1428
Open this publication in new window or tab >>A New Alternative for Obtaining Nanocrystalline Bioactive Coatings: Study of Hydroxyapatite Deposition Mechanisms by Cold Gas Spraying
Show others...
2016 (English)In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 99, no 4, p. 1420-1428Article in journal (Refereed) Published
Abstract [en]

The present article is intended to study the deposition mechanisms of bioactive hydroxyapatite (HA) particles by means of Cold Gas Spraying (CGS). A comparison of the deposition on two different substrates (Ti6Al4V and Al7075T6) and different particle sizes is presented. Although this is a more specific deposition technique for ductile materials, it is here shown that, in certain conditions, ceramic deposition is possible despite the inherent low ductility. The resulting internal structure and the features at the particle-substrate interface are discussed in view of Transmission Electron Microscopy examinations of a Focused Ion Beam lift-out prepared sample. Mainly, under shock compressive loading, the porous sintered powder proceeds through pore collapse, fragmentation and densification as well as grain refinement. The process is described through different plastic mechanisms in ceramics. This opens a new alternative route to produce nanocrystalline HA coatings through a cost-effective process.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2016
Keywords
AEROSOL DEPOSITION, ROOM-TEMPERATURE, CERAMICS, BEHAVIOR, CERMET, MAPS
National Category
Other Materials Engineering Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-65099 (URN)10.1111/jace.14076 (DOI)000373931900047 ()
Available from: 2017-11-17 Created: 2017-11-17 Last updated: 2019-05-27Bibliographically approved
Vilardell, A. M., Cinca, N., Jokinen, A., Garcia-Giralt, N., Dosta, S., Cano, I. G. & Guilemany, J. M. (2016). Real-Time Protein and Cell Binding Measurements on Hydroxyapatite Coatings. Journal of Functional Biomaterials, 7(3), Article ID 23.
Open this publication in new window or tab >>Real-Time Protein and Cell Binding Measurements on Hydroxyapatite Coatings
Show others...
2016 (English)In: Journal of Functional Biomaterials, ISSN 2079-4983, E-ISSN 2079-4983, Vol. 7, no 3, article id 23Article in journal (Refereed) Published
Abstract [en]

Although a lot of in vitro and in vivo assays have been performed during the last few decades years for hydroxyapatite bioactive coatings, there is a lack of exploitation of real-time in vitro interaction measurements. In the present work, real-time interactions for a plasma sprayed hydroxyapatite coating were measured by a Multi-Parametric Surface Plasmon Resonance (MP-SPR), and the results were compared with standard traditional cell viability in vitro assays. MP-SPR is proven to be suitable not only for measurement of molecule–molecule interactions but also molecule–material interaction measurements and cell interaction. Although SPR is extensively utilized in interaction studies, recent research of protein or cell adsorption on hydroxyapatite coatings for prostheses applications was not found. The as-sprayed hydroxyapatite coating resulted in 62.4% of crystalline phase and an average thickness of 24 ± 6 ÎŒm. The MP-SPR was used to measure lysozyme protein and human mesenchymal stem cells interaction to the hydroxyapatite coating. A comparison between the standard gold sensor and Hydroxyapatite (HA)-plasma coated sensor denoted a clearly favourable cell attachment on HA coated sensor as a significantly higher signal of cell binding was detected. Moreover, traditional cell viability and proliferation tests showed increased activity with culture time indicating that cells were proliferating on HA coating. Cells show homogeneous distribution and proliferation along the HA surface between one and seven days with no significant mortality. Cells were flattened and spread on rough surfaces from the first day, with increasing cytoplasmatic extensions during the culture time.

Place, publisher, year, edition, pages
MDPI, 2016
National Category
Materials Engineering
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-65235 (URN)10.3390/jfb7030023 (DOI)000446638100008 ()
Available from: 2017-11-17 Created: 2017-11-17 Last updated: 2019-08-02Bibliographically approved
Vilardell, A. M., Cinca, N., Concustell, A., Dosta, S., Cano, I. G. & Guilemany, J. M. (2015). Cold spray as an emerging technology for biocompatible and antibacterial coatings: State of art. Journal of Materials Science, 50(13), 4441-4462
Open this publication in new window or tab >>Cold spray as an emerging technology for biocompatible and antibacterial coatings: State of art
Show others...
2015 (English)In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 50, no 13, p. 4441-4462Article, review/survey (Refereed) Published
Abstract [en]

The use of coatings in biomaterials has been fundamental on the applicability of many medical devices and has helped improve mechanical properties such as wear and fatigue and biological properties such as biocompatibility and bioactivity of implant prosthesis, thus, in essence, ameliorating human quality life. The aim of the present paper is to give a review on cold spray (CS) coating systems that are emerging in orthopedics industry (internal fixation systems and prosthesis) as well as those for antibacterial purposes (in body and touch external surfaces). These studies are very new, the oldest dating from the half of last decade and most deal with the improvement of biocompatibility and bioactivity of hard tissue replacement; therefore, research on biocoatings is in constant development with the aim to produce implant surfaces that provide a balance between cell adhesion and low cytotoxicity, mechanical properties, and functionalization. CS offers many advantages over conventional high-temperature processes and seems to be able to become competitive in front of the low-temperature techniques. It is mainly cost effective, appropriate for oxygen-sensitive materials, and environmentally green. It basically involves the use of feedstock material in powder form, which is supersonically sprayed onto the appropriate substrate but without any melting as it occurs in conventional thermal spray processes. Biocompatible metallic materials and polymers have been successfully deposited by this method because it is based on the plasticity of the coating material; pure ceramic deposits, for example of hydroxyapatite, are still a challenge.

Place, publisher, year, edition, pages
New York: Springer, 2015
National Category
Biomaterials Science Materials Engineering Bio Materials Manufacturing, Surface and Joining Technology
Research subject
Materials Engineering
Identifiers
urn:nbn:se:kau:diva-65095 (URN)10.1007/s10853-015-9013-1 (DOI)000354093500001 ()
Available from: 2017-11-02 Created: 2017-11-02 Last updated: 2019-05-27Bibliographically approved

Search in DiVA

Show all publications