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The purpose of this paper is to focus on the investigation of nanomechanical behavior of new types of metal alloys protective coatings. For this purpose, poly(n-butylacrylate) was synthesized via activators regenerated by electron transfer-atom transfer radical polymerization and mixed with epoxy resins, and microcomposites.

Multi-layered coatings were applied on hot dip galvanized steel via a baker film applicator. Every layer containing the aforementioned copolymer differs in the proportion of the epoxy resin resulting in the production of a coating with a gradient from hard to soft from the substrate to the top. Nanomechanical performance is accessed via nanoindentation, providing information for structural and mechanical integrity, adhesion and resistance to wear.

The results reveal that through trajection of hardness mapping, the resistance is divided in three regions, namely, the polymer (matrix), interface (region close to/between spheres-shells) and spheres-shell regions.

The structural analysis, adhesion and mechanical integrity of the coatings are clearly demonstrated.

The purpose of this paper is to focus on the investigation of mechanical and thermal properties of lignin/poly (ethylene oxide) (PEO) blends, intended to be used as carbon fiber precursor.

Softwood kraft lignin was modified via esterification using phthalic anhydride and then blended with PEO. The final lignin/PEO ratios blends were (w/w) 20/80, 50/50 and 80/20 for both unmodified and modified lignin. The structural, thermal and mechanical properties of the blends were investigated by Fourier transform infrared, differential scanning calorimetry and tensile tests, respectively.

The results revealed that modified lignin/PEO blend (20/80) exhibited enhanced elongation.

The structural analysis as well as thermal and mechanical properties of the produced blends are clearly demonstrated.

The purpose of this paper is to develop modified composite materials that show improved mechanical and structural integrity.

To accomplish this goal, a novel functionalisation method of the carbon fibres (CFs) for the reinforcement of the composites surface was investigated. Through the electrografting of methacrylic acid (MAA) onto the surface of the CF, this treatment aims to selectively modify the surface of the carbon fabrics, in order to create active groups that can chemically react with the epoxy resin, under heat and pressure. By this way, better adhesion as mechanical interlocking between the resin and the reinforcement can be achieved.

The surface treatment was examined qualitatively by means of infrared spectroscopy, scanning electron microscopy and Raman spectroscopy. The CF reinforced polymers were manufactured via the hot-press technique and they were subsequently submitted to flexural, shear and nanoindentation test. Finally, the internal structural integrity was tested through micro-computing tomography.

Through this investigation, it will be determined if the electropolymerisation of MAA onto the CF surface enhances the mechanical and structural integrity of composite materials.

Carbon nanotube-based architectures have increased the scientific interest owning to their exceptional performance rendering them promising candidates for advanced industrial applications in the nanotechnology field. Despite individual CNTs being considered as one of the most known strong materials, much less is known about other CNT forms, such as CNT arrays, in terms of their mechanical performance. The paper aims to discuss these issues.

In this work, thermal CVD method is employed to produce VA-MWCNT carpets. Their structural properties were studied by means of SEM, XRD and Raman spectroscopy, while their hydrophobic behavior was investigated via contact angle measurements. The resistance to indentation deformation of VA-MWCNT carpets was investigated through nanoindentation technique.

The synthesized VA-MWCNTs carpets consisted of well-aligned MWCNTs. Static contact angle measurements were performed with water and glycerol, revealing a rather super-hydrophobic behavior.

The structural analysis, hydrophobic behavior and indentation response of VA-MWCNTs carpets synthesized via CVD method are clearly demonstrated.

The purpose of this paper is to deal with the study of properties of anticorrosion powder based coatings on aluminium alloy 2024.

The powder based coatings were applied to the AA2024 substrates using a spray coating technique. All the substrates were covered with a primer prior the powder based coatings. The morphology and composition of the coatings was examined by scanning electron microscopy and energy dispersive X-ray analysis, respectively. Studies on the corrosion resistance of these coatings were made using electrochemical impedance spectroscopy.

The results reveal that the powder based coatings together with the primer coatings demonstrate improved corrosion protection to AA2024 after exposure to corrosive environment. Moreover, the primer coating is mechanically enhanced compared to the top coating, while the top coating exhibited significant resistance to wear.

The paper deals with the evaluation of corrosion and nanomechanical properties of coatings applied on aluminium alloy.

Lightweight alloys are of major concern, due to their applicability, in transport and industry applications. The purpose of this paper is to perform a comprehensive analysis of time dependent properties of aluminum alloy by nanoindentation technique, through investigation of creep behavior. Additionally, possible explanations on the time dependent behavior and the influence of the hold period at maximum load and the loading rate on the elastic modulus and hardness results are also analyzed and discussed.

In this work, a comprehensive analysis of time dependent properties of aluminum alloy by nanoindentation technique was performed, by varying the loading rate, the maximum applied load and the loading time. The stress exponent values are derived from the displacement‐holding time curves. The present experimental setup includes three different approaches: variation of loading rate, maximum applied load and loading time. The creep deformation mechanisms of the alloy, which are dependent on experiment setup, are discussed and the characteristic “elbow” behavior in the unloading part of the curves is also reported.

The authors found that the stress exponent values obtained are dependent on the applied peak loads and indentation loading rates. Nanoindentation creep testing of aluminum AA6082‐T6 revealed significant creep displacements, where the strain rate reached a steady state after a certain time and the stress decreased with time as the displacement increased during the creep process. The slopes of strain rate versus stress curves (exponent of power‐law creep) for different maximum loads and various holding times, were investigated.

The stress exponent of the constant‐load indentation creep, in all three types of experiments, was found to reduce at low load region. In case of different holding load and time, the stress exponent increased almost linearly and increased very rapidly as the indent size increased, exhibiting an intense size effect.

The purpose of this paper is to produce cobalt (Co)-based thin films by metalorganic chemical vapor deposition (CVD) technique and then to evaluate structural and mechanical integrity.

Co-based thin films were produced by metalorganic CVD technique. Boronizing, carburization and nitridation of the produced Co thin films were accomplished through a post-treatment stage of thermal diffusion into as-deposited Co thin films, in order to produce cobalt boride (Co₂B), cobalt carbide and cobalt nitride thin films in the surface layer of Co. The surface topography and the crystal structure of the produced thin films were evaluated through scanning electron microscopy and X-ray diffraction, respectively. The mechanical integrity of the produced thin films was evaluated through nanoindentation technique.

The obtained results indicate that Co₂B thin film exhibits the highest nanomechanical properties (i.e. H and E), while Co thin film has enhanced plasticity. The cobalt oxide thin film exhibits higher resistance to wear in comparison to the cobalt thin film, a fact that is confirmed by the nanoscratch analysis showing lower coefficient of friction for the oxide.

This work is original.

The purpose of this paper is to perform the evaluation of copper susceptibility to corrosion in industrial cooling systems. Microstructure and defects of copper are observed, while divergences from optimum structure are discussed.

Various types of corrosion are examined. Electrochemical techniques such as electrochemical impedance spectroscopy and potentiodynamic polarisation are applied in these materials, using corrosion inhibitors. Microscopic observations and electrochemical measurements are interpreted according to possible mechanistic scenarios.

It is evident that, under specific conditions (e.g. high pH), water cooling ingredients can enhance corrosion, leading to significant copper mass loss from the inner surface of the pipe and thus leading to failure.

Evaluation of copper corrosion in cooling industrial systems was done, as well as studies of copper corrosion in sodium chloride.

The study of nanoindentation as a reliable method to extract creep properties as well as for fundamental understanding of deformation mechanisms at small length scales is an open interesting field. The observed creep behavior is attributed to time-dependent plastic deformation based on loading rates. There is a lot of work in the field of nanoindentation in order to understand the dynamic effects on nanomechanical properties. The paper aims to discuss these issues.

The deformation mechanism is investigated under two experimental approaches (high and low loading rates, respectively) during nanoindentation. The effect of loading rate in the nanomechanical properties, during nanoindentation creep of zinc layer on hot dip galvanized (HDG) steel, is discussed through nanoindentation.

Analysis of this research effort is emphasized on nanoindentation stress exponent, a critical parameter for the life time and reliability of nano/micro-materials and systems. The corrosion resistance was studied by electrochemical impedance spectroscopy (EIS) and localized EIS.

The study of nanoindentation as a reliable method to extract creep properties as well as for fundamental understanding of deformation mechanisms at small length scales is an open interesting field. The observed creep behavior is attributed to time-dependent plastic deformation based on loading rates. The deformation mechanism is investigated under two experimental approaches (high and low loading rates, respectively) during nanoindentation. The effect of loading rate in the nanomechanical properties, during nanoindentation creep of zinc layer on HDGsteel, is discussed through nanoindentation. Analysis of this research effort is emphasized on nanoindentation stress exponent, a critical parameter for the life time and reliability of nano/micro- materials and systems. The corrosion resistance was studied by EIS and localized EIS.

The purpose of this paper is to determine if the nanoindentation technique is a reliable method and whether it can be used to measure the surface hardness (H) in friction stir welded aluminum alloys. In order to test the reliability of nanoindentation technique, nanohardness values for friction stir welded aluminum alloys were compared to microhardness values. Additionally, the onset of plasticity (yielding) is investigated.

Nanoindentation experiments were performed for the determination of onset on plasticity (yielding) and comparison of local mechanical properties of both welded alloys. In order to test the reliability of nanoindentation technique, nanohardness values for friction stir welded AA6082 were compared to microhardness values. The specimen was tested using two different instruments – a Vickers microhardness tester and a nanoindenter tester for fine scale evaluation of H.

The results of this study indicate that nanohardness values with a Berkovich indenter reliably correlate with Vickers microhardness values. Nanoindentation technique can provide reliable results for analyzing friction stir welded aluminum alloys. The welding process definitely affects the material mechanical properties.

Microhardness and nanohardness obtained values can be correlated carefully, regarding the similarities and the differences of the two above mentioned techniques.