Corrosion and passive film characteristics of 3D-printed NiTi shape memory alloys in artificial saliva

Electrochemical tests and surface analysis were applied to study the corrosion behavior and passive film characteristics of three-dimensional-printed NiTi shape memory alloys fabricated by laser-powder bed fusion (L-PBF) in artificial saliva at 37 °C. The passivity of L-PBF NiTi shows to be influenced by the process parameters and resulting...

Fabrication of graphene oxide-modified self-healing microcapsules for Cardanol-based epoxy anti-corrosion coatings

In this paper, graphene oxide (GO) modified microcapsules have been developed for use in self-healing Cardanol-based epoxy anti-corrosion coatings on steel substrates. The microcapsules had a polymethyl methacrylate (PMMA) shell, covered with aminated GO flakes and contained either of the two complementary healing agents mixed with nanosized...

Antimicrobial properties dependence on the composition and architecture of copper-alumina coatings prepared by plasma electrolytic oxidation (PEO)

This study presents environmentally friendly and low-cost synthetic routes to produce antimicrobial coatings over 5052 Al alloy based on plasma electrolytic oxidation (PEO) technology. Two methodologies were explored: the decoration with copper and anodic doping with copper ions. The porous oxide layers produced in silicate media presented...

Microbiologically Induced Concrete Corrosion: A Concise Review of Assessment Methods, Effects, and Corrosion-Resistant Coating Materials

Microbiologically induced concrete corrosion (in wastewater pipes) occurs mainly because of the diffusion of aggressive solutions and in situ production of sulfuric acid by microorganisms. The prevention of concrete biocorrosion usually requires modification of the mix design or the application of corrosion-resistant coatings, which requires a...

Application of ultra-fine fly ash as cement replacement for sustainable concrete with optimal packing design

In the present study, a proprietary 0.2 tonne/h Dusty Cloud Separation (DCS) technology prototype by Value Ash Technologies NV (Belgium) was used to obtain ultra-fine fly ash as a novel by-product. Two types of Class F fly ash were used: separated fly ash (FA1) with particle size < 9.3 μm and ultra-fine fly ash (FA2) < 4.6 μm as sub-fraction of...

Improved corrosion protection of titanium implant material by crystallographic texturing of Sr doped calcium phosphate electrodeposits

Nanocrystalline calcium phosphate (CaP) coatings can provide biocompatibility and corrosion protection to biomaterials upon implementation in the human body. While the long term stability of recently developed coatings in biological environment proves to be challenging, the present work tailors the surface by orienting the growth ...

An investigation on the hardness and corrosion behavior of MWCNT/Mg composites and grain refined Mg

In the present work, multi walled carbon nanotubes (MWCNT) reinforced magnesium (Mg) matrix composite was fabricated by friction stir processing (FSP) with an aim to explore its mechanical and electrochemical behavior. Microstructural observations showed that the thickness of the produced composite layer was in the range of 2500 μm. FSP...

Properties and performance of spin-on-glass coatings for the corrosion protection of stainless steels in chloride media

Spin-on-glass deposition was investigated as viable alternative to increase the durability and performance of 316L steel in chloride environment. The buildup of a detrimental interface oxide was prevented by non-oxidative thermal curing of the coatings, which leads to a transformation to an inorganic, SiO₂-like material. The degree...

Adhesive bonding and corrosion performance investigated as a function of auminum oide chemistry and adhesives

The long-term strength and durability of an adhesive bond is dependent on the stability of the oxide-adhesive interface. As such, changes in the chemistry of the oxide and/or the adhesive are expected to modify the interfacial properties and affect the joint performance in practice. The upcoming transition to Cr(VI)-free surface pretreatments...

Life extension in protective coatings via self-healing technology

As the field of self-healing materials continues to grow, novel self-healing concepts and chemistries are being developed for a variety of applications including coatings. Self-healing functionality is typically considered for incorporation in coatings to solve two basic challenges including restoration of aesthetic properties and restoration of...

Corrosion Performance of Carbon Steel in Simulated Pore Solution in the Presence of Micelles

This study presents the results on the investigation of the corrosion behavior of carbon steel in model alkaline medium in the presence of very low concentration of polymeric nanoaggregates [0.0024 wt % polyethylene oxide (PEO)113-b-PS70 micelles]. The steel electrodes were investigated in chloride free and chloride-containing cement extracts....

Variability of fatigue crack growth properties for 2024-T3 aluminium alloy

Discussions between D-BAA and the NLR have shown that significant variability in fatigue crack growth properties is possible for the industry standard damage tolerant aluminium alloy, 2024-T3 sheet. This is important for two reasons: (1) design assumptions and (2) comparisons of different candidate materials, such as 6013-T6, with 2024-T3....

Stress corrosion resistance of damage tolerant aluminium-lithium sheet materials

The SCC resistances of three damage tolerant aluminium sheet materials were determined by means of the ASCOR (Automated Stress COrrosion Ring) test. The conventional damage tolerant sheet material 2024-T3 was used as reference. The SCC resistance of 8090-T81 turned out to be only slightly lower than the SCC resistance of 2024-T3. In contrast,...

Outdoor corrosion testing of aluminium-lithium alloys

Outdoor corrosion and stress corrosion tests were conducted on Al-Li plate and sheet materials for 3 and almost 5 years respectively. The results can be summarized as follows: Corrosion: Peak aged XXXA-T651 (8090-T651) exhibited greater exfoliation corrosion resistance than 2024-T351 and 2324-T39 plate. 2091-T3 and 2024-T3 sheet were found to be...

Long-term outdoor stress corrosion testing of overaged 7000 series aluminium alloys

Long-term outdoor stress corrosion tests were executed on overaged 7000 series aluminium alloy plate and forgings. Plate material of the alloys 7010-T7651, 7010-T7451 and 7075-T7351 exhibited an excellent resistance to SCC. PM alloy X7091-T7E69 forgings combined a higher strength with superior SCC resistance as compared to IM alloy forgings. The...

Stress corrosion crack initiation testing of high strength aluminium alloys using tuning fork type specimens

An experimental investigation was carried out into the applicability of various corrosive environments for stress corrosion crack initiation testing of high strength aluminium alloys using constant strain loaded tuning fork type specimens. The effect of surface preparation was also involved. The most important findings were that salt-chromate...

Influence of environmental ageing and displacement rate on crack resistance of adhesives, as determined on adhesive bonded TDCB-specimens

Fracture toughness measurements were carried out to test the ageing behaviour of three adhesives in different environments. It was possible to compare and evaluate adhesives and surface pretreatments. It is doubtful whether the derived R-curves could be used for residual strength calculations in certain environments. Phosphoric acid anodizing...

Aluminium alloys for advanced structural applications in transport aircraft

This paper concisely reviews and discusses (1) metallurgically cleaner alloys like -2124, 2048 and 7475, (2) potential application of 7000 series alloys in tension panels, (3) development of high strength stress corrosion resistant thick section materials like 7010, 7049 and 705O, (4) powder metallurgy 7000 series alloys with high strength and...