Growth and Dissolution of Protective Oxide Films on Titanium: an in-Situ Neutron Reflectivity Study

1994 ◽  
Vol 376 ◽  
Author(s):  
D.G. Wlesler ◽  
C.F. Majkrzak
Keyword(s):  
Silicon Crystal ◽  
Electrolyte Composition ◽  
Neutron Reflectometry ◽  
Neutron Reflectivity ◽  
Self Healing ◽  
Protective Oxide ◽  
Structure And Morphology ◽  
Titanium Thin Film ◽  
Protective Oxide Film

ABSTRACTThe structure and morphology of titanium thin film electrodes have been investigated by neutron reflectometry. This technique yields a detailed depth profile of the scattering density, which is used to determine hydrogen and oxygen concentration profiles within the electrode. By depositing the electrode on a thick silicon crystal window, we are able to monitor the growth and dissolution of the protective oxide film covering the titanium as a function of time, electrode potential, and electrolyte composition. We find that, in 0.1 N sulfuric acid, the oxide dissolves at 0.7 A/h and is self-healing, meaning that as the oxide dissolves the metal underneath is oxidized to maintain a protective barrier. In contrast, when a -2 V cathodic bias is applied to a passive film, the oxide thins with no compensating oxide growth underneath, and the film undergoes electrochemical breakdown.

scholarly journals Influence of Hybrid Sol-Gel Crosslinker on Self-Healing Properties for Multifunctional Coatings

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5382
Author(s):  
Guillaume Lollivier ◽  
Marie Gressier ◽  
Florence Ansart ◽  
Maëlenn Aufray ◽  
Marie-Joëlle Menu
Keyword(s):  
Sol Gel ◽  
Interface Layer ◽  
Hybrid Coatings ◽  
Organic Polymer ◽  
Self Healing ◽  
Oxide Interface ◽  
Protective Oxide ◽  
New Class ◽  
One Step

Self-healing polymers are a new class of material that has recently received a lot of attention because of the lifespan improvement it could bring to multiple applications. One of the major challenges is to obtain multifunctional materials which can self-heal and exhibit other interesting properties such as protection against corrosion. In this paper, the effect of the incorporation of an aminosilane on the properties of a self-healing organic polymer containing disulfide bond is studied on films and coatings for aluminium AA2024-T3 using simple one step in situ synthesis. Hybrid coatings with enhanced anticorrosion properties measured by EIS were obtained thanks to the formation of a protective oxide interface layer, while exhibiting wound closure after exposition at 75 °C. The thermal, mechanical and rheological properties of the films with different aminosilane amounts were characterized in order to understand the influence of the slight presence of the inorganic network. Stiffer and reprocessable hybrid films were obtained, capable to recover their mechanical properties after healing. The nanocomposite structure, confirmed by TEM, had a positive effect on the self-healing and stress relaxation properties. These results highlight the potential of sol-gel chemistry to obtain efficient anticorrosion and self-healing coatings.

scholarly journals In-Situ Laser Directed Energy Deposition of Biomedical Ti-Nb and Ti-Zr-Nb Alloys from Elemental Powders

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1205
Author(s):  
Felipe Arias-González ◽  
Alejandra Rodríguez-Contreras ◽  
Miquel Punset ◽  
José María Manero ◽  
Óscar Barro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Energy Deposition ◽  
Titanium Implants ◽  
Protective Oxide ◽  
Directed Energy Deposition ◽  
Protective Oxide Film ◽  
Directed Energy ◽  
Stable Passive

In order to achieve the required properties of titanium implants, more resources and research are needed to turn into reality the dream of developing the perfect implant material. The objective of this study was to evaluate the viability of the Laser Directed Energy Deposition to produce biomedical Ti-Nb and Ti-Zr-Nb alloys from elemental powders (Ti, Nb and Zr). The Laser Directed Energy Deposition is an additive manufacturing process used to build a component by delivering energy and material simultaneously. The material is supplied in the form of particles or wire and a laser beam is employed to melt material that is selectively deposited on a specified surface, where it solidifies. Samples with different compositions are characterized to analyze their morphology, microstructure, constituent phases, mechanical properties, corrosion resistance and cytocompatibility. Laser-deposited Ti-Nb and Ti-Zr-Nb alloys show no relevant defects, such as pores or cracks. Titanium alloys with lower elastic modulus and a significantly higher hardness than Ti grade 2 were generated, therefore a better wear resistance could be expected from them. Moreover, their corrosion resistance is excellent due to the formation of a stable passive protective oxide film on the surface of the material; in addition, they also possess outstanding cytocompatibility.

Enhancing oxidation resistance of Cu during repeated melting by the in-situ formation of protective oxide films

2021 ◽  
Vol 286 ◽  
pp. 129234
Author(s):  
Yongli Guo ◽  
Hui Cai ◽  
Zhe Wang ◽  
Xin Wang ◽  
Peng Cao ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Oxide Films ◽  
Protective Oxide ◽  
In Situ Formation

Recyclable conductive nanoclay for direct in situ printing flexible electronics

2021 ◽  
Author(s):  
Pengcheng Wu ◽  
Zhenwei Wang ◽  
Xinhua Yao ◽  
Jianzhong Fu ◽  
Yong He
Keyword(s):  
Flexible Electronics ◽  
Self Healing ◽  
Stamping Process

A recyclable, self-healing conductive nanoclay and corresponding stamping process are developed for printing flexible electronics directly and quickly in situ.

Formation of Polyelectrolyte Multilayer Architectures with Embedded DMPC Studied in Situ by Neutron Reflectometry

Langmuir ◽  
2005 ◽  
Vol 21 (18) ◽  
pp. 8509-8514 ◽  
Author(s):  
Christophe Delajon ◽  
Thomas Gutberlet ◽  
Roland Steitz ◽  
Helmuth Möhwald ◽  
Rumen Krastev
Keyword(s):  
Neutron Reflectometry ◽  
Polyelectrolyte Multilayer

SELF-HEALING OF WOVEN COMPOSITE LAMINATES VIA IN SITU THERMAL REMENDING

2021 ◽  
Author(s):  
ALEXANDER D. SNYDER ◽  
ZACHARY J. PHILLIPS ◽  
JASON F. PATRICK
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Laminated Composites ◽  
Reaction Times ◽  
Carbon Fiber Composites ◽  
Self Healing ◽  
Damage Mode ◽  
Woven Composite ◽  
Internal Damage

Fiber-reinforced polymer composites are attractive structural materials due to their high specific strength/stiffness and excellent corrosion resistance. However, the lack of through-thickness reinforcement in laminated composites creates inherent susceptibility to fiber-matrix debonding, i.e., interlaminar delamination. This internal damage mode has proven difficult to detect and nearly impossible to repair via conventional methods, and therefore, remains a significant factor limiting the reliability of composite laminates in lightweight structures. Thus, novel approaches for mitigation (e.g., self-healing) of this incessant damage mode are of tremendous interest. Self-healing strategies involving sequestration of reactive liquids, i.e. microcapsule and microvascular systems, show promise for the extending service- life of laminated composites. However, limited heal cycles, long reaction times (hours/days), and variable stability of chemical agents under changing environmental conditions remain formidable research challenges. Intrinsic self- healing approaches that utilize reversible bonds in the host material circumvent many of these limitations and offer the potential for unlimited heal cycles. Here we detail the development of an intrinsic self-healing woven composite laminate based on thermally-induced dynamic bond re-association of 3D-printed polymer interlayers. In contrast to prior work, self-repair of the laminate occurs in situ and below the glass-transition temperature of the epoxy matrix, and maintains >85% of the elastic modulus during healing. This new platform has been deployed in both glass and carbon-fiber composites, demonstrating application versatility. Remarkably, up to 20 rapid (minute-scale) self-healing cycles have been achieved with healing efficiencies hovering 100% of the interlayer toughened (4-5x) composite laminate. This latest self-healing advancement exhibits unprecedented potential for perpetual in-service repair along with material multi-functionality (e.g., deicing ability) to meet modern application demands.

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