... Therm. Spray Technol. 6 (1997), p. 205. Full Text via CrossRef | View Record in Scopus | Cite... more ... Therm. Spray Technol. 6 (1997), p. 205. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (27). [2] AA Abdel-Samad, AMM El-Bahloul, E. Lugscheider and SA Rassoul, J. Mater. Sci. 35 (2000), p. 3127. Full ...
In order to improve the biocompatibility with the osseous tissue of metallic implants for orthope... more In order to improve the biocompatibility with the osseous tissue of metallic implants for orthopedic and maxillofacial surgery, these were coated with calcium phosphate (CaP) bioceramics such as Hydroxyapatite (HAp). Electrochemical deposition (ED) has attracted considerable attention due to the number of advantages like coating method over the generally used plasma spray technique. This research evaluates the influence of processing parameters, current density and substrate superficial treatment on the microstructure, adhesion and corrosion resistance of ED-HAp coatings. The thickness, structure and composition of the coatings were investigated by X-ray diffraction (XRD), and scanning electron microscopy (SEM). Impedance Spectroscopy was used to evaluate the adhesion and corrosion resistance of coatings and their dependence on fabrication parameters. The results showed that the thickness increase with the applied deposition current density. The potential vs time curves showed that the Calcium Phosphate deposition progresses with the initial reduction on the alloy surface oxide layer where reduction of nitrate ions takes place on the active free surface sites. The kinetics of this process is enhanced by sufficiently high current densities. Such current densities have a direct influence on the local pH of the solution and determine the morphology, structure and composition of ED-HAp deposited.
Una protesis total de cadera es un implante utilizado en el reemplazo total de la cadera en caso ... more Una protesis total de cadera es un implante utilizado en el reemplazo total de la cadera en caso de lesiones traumaticas o degenerativas. El presente trabajo tiene como objetivo determinar la causa de la falla de una protesis total de cadera en un paciente que presento dolor e impotencia articular manifiesta. Con tal fin se aplico la metodologia caracteristica de un analisis de falla: analisis quimico, estudio metalografico de cabeza y vastago, evaluacion por microscopia electronica de barrido de la superficie fallada y microanalisis quimico por energia dispersiva (EDAX). En la realizacion del analisis medico del caso se consideraron aspectos tales como: tiempo de permanencia del implante en el paciente antes de la falla, actividades realizadas por el paciente, tipo de lesion que amerito el implante, edad, otros. Adicionalmente se realizo un estudio anatomopatologico en los tejidos circundantes al vastago por evidente presencia de metal. El estudio anatomopatologico revelo una fuert...
En estudios realizados sobre la utilizacion de los implantes metalicos que se utilizan en cirugia... more En estudios realizados sobre la utilizacion de los implantes metalicos que se utilizan en cirugia ortopedica traumatologica en Venezuela, se concluye que un elevado numero de casos fallan antes del tiempo de su vida util. Esto trae como consecuencia molestias para el paciente, porque se necesita una nueva intervencion para extraer el implante y colocar uno nuevo, perdidas de horas/hombre en pacientes en etapa laboral y en los medicos, asi como perdida de recursos materiales. En el presente trabajo se muestran los resultados del analisis de falla de dos casos de implantes utilizados en cirugia ortopedica y traumatologica en Venezuela. La metodologia utilizada contemplo la realizacion de analisis quimicos, estudios metalograficos, analisis fractograficos por microscopia electronica de barrido y microanalisis quimico por energia dispersiva (EDAX) En la realizacion del analisis medico se consideraron tecnicas quirurgicas defectuosas de implantacion, tiempo de permanencia del implante en...
Tungsten carbide WC-based composites are widely used in various wear applications requiring a com... more Tungsten carbide WC-based composites are widely used in various wear applications requiring a combination of high toughness, high hardness, and good strength. Some researchers have demonstrated that WC-Co coatings with WC particles in the nanoscale range offer improved properties over their conventional counterparts. This work examines the performance of such conventional and nanostructured materials in the form of coatings deposited by high velocity oxy-fuel (HVOF) thermal spraying. The optimal deposition parameters of nanocomposite powders of WC-12%Co were previously determined. The performance of the coatings was examined under abrasion and sliding conditions. Improvements in mechanical properties and wear resistance were obtained from the nanocomposite coating and the results were attributed to more retained WC and consequently a lower amount of non-WC phases whose presence is detrimental to wear resistance. Also was found that the hardness and fracture toughness of the coatings...
ABSTRACT WC-Co is widely used as a tribological coating material providing a combination of high ... more ABSTRACT WC-Co is widely used as a tribological coating material providing a combination of high toughness, high hardness, and good strength. Herein, an attempt has been made to further enhance the mechanical and wear properties of tungsten carbide cobalt coatings by reinforcing them with multi wall carbon nanotubes (CNTs) using thermal spraying. In this work, 0.35 wt.% of CNTs were mixed by jar-milling in ethanol solution with WC-12%Co microcrystalline powders for different blending times. The mixture was thermally sprayed using the HVOF process onto a plain steel substrate. Also, coatings deposited with both WC-12%Co microcrystalline and nanostructured powders, using the same thermal spray process, were evaluated and compared with samples reinforced with CNTs. The microstructures of the coatings were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Raman Spectroscopy and X-ray diffraction (XRD). The microhardness was measured by Vickers indentation and the abrasive wear resistance was evaluated using a dry sand rubber wheel technique according to ASTM G-65-00 standard. Effects of blending times of CNTs on the microstructure, abrasion wear and microhardness of the coatings were investigated. Experimental results shown that 36 hours of milling time was suitable to disperse CNTs with WC-Co feed powders since it produces an adequate relationship between CNTs´ dispersion time and particle size which enhances the microhardness and porosity of the coatings. The C-36 coating showed an increase in wear resistance of almost 80% and 70% compared with conventional and nanostructured coatings, respectively. This was attributed to the CNTs acting as bridges, promoting the cohesion between lamellas and reducing the decarburization. All reinforced coatings showed a higher abrasive wear resistance than non-reinforced indicating that CNTs are a good alternative to improve abrasion wear resistance of WC-Co coatings.
IOP Conference Series: Materials Science and Engineering, 2013
The present work shows the analysis of a sandblasting process using alumina abrasive particles on... more The present work shows the analysis of a sandblasting process using alumina abrasive particles on Ti-6Al-4V surfaces. The metallic samples were first characterized by optical microscopy (OM), revealing an α+β microstructure with a Widmanstatten morphology. Topography of the samples was assessed by scanning electron microscopy (SEM), before and after sandblasting. The Al2O3 particles used had a granulometric distribution between 420 and 850 μm, with a median particle size (d50) of 670 μm, which decreased to 420 μm after sandblasting for 10 seconds. This change in the size of the particles generated a loss on particle kinetic energy by a factor of 3.5. Such variation on processing conditions induced a progressive increase on average roughness (Ra) of the Ti-6Al-4V surfaces, until the first 7 seconds were reached. From that point on, a reverse process was observed, exerting a polishing effect on the surface of the Ti-6Al-4V alloy.
This paper proposes to evaluate and characterize the damage produced by electrochemical corrosion... more This paper proposes to evaluate and characterize the damage produced by electrochemical corrosion in AISI/SAE 1045 medium carbon steel surfaces, modified with titanium and titanium+nitrogen ions by three-dimensional ion implantation technique. By means of electrochemical tests such as linear polarization resistance, potentiodynamic polarization, and electrochemical impedance spectroscopy; it was quantified and compared the performance of non-implanted and implanted samples against electrochemical corrosion. From the results, it was found a considerable improvement in the performance of the surface-modified ferrous alloy in comparison with bare specimens. The degradation occurred after exposition in the saline environment was reduced up to 50% in terms of mass-loss or corrosion rates. Likewise, the inspection of the state and composition of AISI/SAE 1045 medium carbon steel microstructure, after the surface modification and chemical attack, by microscopy and spectroscopy characteriza...
The resistance to abrasive wear of two hardfacing alloys containing either high Cr or high W was ... more The resistance to abrasive wear of two hardfacing alloys containing either high Cr or high W was studied. The alloys were deposited onto AISI A36 steel plates by a SMAW procedure. An alloy applied by oxyacetylene welding was used as comparison material. Wear resistance was measured in a dry sand – rubber wheel testing machine according to ASTM G65 standard, procedure A. The worn surfaces and the microstructure of the samples were analyzed in optical and scanning electron microscope, while the hardness of the deposits was measured in a Rockwell hardness tester. The best abrasion resistance was obtained in microstructures composed of primary (Fe,Cr)7C3 carbides and eutectic matrix, while higher mass losses were measured in Fe-Cr-C specimens containing primary austenite. The FeW-C hardfacing also showed good abrasion resistance due to the high hardness and deformability of the structure.
The objective of this work was to characterize the corrosive deterioration of the galvanizedcompo... more The objective of this work was to characterize the corrosive deterioration of the galvanizedcomponents of assembly of the structure of an electrical power transmission tower. For this, a visualinspection accompanied by a metallographic analysis, thickness measurement of the galvanized,morphological analysis by scanning electron microscopy (SEM) with chemical microanalysisby dispersive energy (EDX) was carried out. The results obtained show that the metal components evaluated have two clearly differentiable zones in terms of surface tonality: a clear and a dark zone, which indicates the presence of a preferential corrosive deterioration of the coating. The microanalysis by EDX carried out in these zones shows that the damage by corrosion and the consequent loss of thickness of the zinc protective coating of the evaluated components is associated with the presence of atmospheric pollutants. It is concluded that the capacity of protection against corrosion of the galvanized remaining i...
Revista Latinoamericana de Metalurgia y Materiales
The thermal sprayed WC-Co coatings are commonly used in industrial applications in which wear res... more The thermal sprayed WC-Co coatings are commonly used in industrial applications in which wear resistance is needed. Nevertheless, the coatings often present certain problems like not melting or semi-molten particles, poor adhesion to the substrate, low cohesion between particles amongst each other, which could affect the behavior of the coatings. The aim of this work is to investigate the effect of the oxyacetylene flame post heat treatment on the wear resistance of a WCCo- NiCrBSi coating thermally sprayed using a high velocity oxy-fuel (HVOF) process on an AISI 1020 steel substrate. The wear behavior of the coatings with and without post heat treatment was evaluated by erosion test, rubber wheel tests and pin-on-disk tests. It was determined that the abrasion resistance of the post heat treated coatings increased 67% compared with the sample without treatment, which could be attributed to a less porosity, matrix hardening and better cohesion between the hard particles produced by ...
Journal of Applied Biomaterials & Functional Materials, 2015
Background In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most ... more Background In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most widely used alloy in orthopedic implants, so as to improve the biological tissue response at the metallic surface. Methods The Ti6Al4V surface was sandblasted with alumina particles. CH was chemically modified, via carbodiimide chemistry, using lactobionic and 4-azidebenzoic acid to make it soluble at physiological pH and photocrosslinkable, respectively. The reaction was verified by FTIR, NMR and UV/vis spectroscopy. Ti6Al4V surfaces were coated with solutions of the modified CH and exposed to UV light, causing polymer crosslinking and formation of a hydrogel on the surface. The crosslinking reaction was monitored by FTIR at different exposure times. Coating morphology was observed by SEM. The coating's cytocompatibility was determined in vitro through the culture of rat bone marrow mesenchymal stem cells, using an MTT assay, with their morphology assessed by SEM. Results The develo...
ABSTRACT The present study has been carried out to evaluate the corrosion performance of three di... more ABSTRACT The present study has been carried out to evaluate the corrosion performance of three different (Ti1?xAlx)N/TiN multilayers coatings commercially deposited on WC?Co inserts. Two of these coatings were nanostructured, and all of them presented different Ti/Al atomic ratios varying from 2 : 3 up to 7 : 3 and were deposited by employing a commercial physical vapour deposition cathodic arc process. X-ray diffraction analysis indicated that the grain size for both the TiAlN and TiN layers in the coatings architecture, varied between approximately 9 to 14 nm. The corrosion performance was evaluated in a 3 wt-%NaCl solution using both open circuit potential and potentiodynamic polarisation measurements. Scanning electron microscopy and energy dispersive spectroscopy surface characterisation before and after corrosion testing allowed the determination that all the coatings under study show a corrosion current density of approximately one order of magnitude smaller than the uncoated substrate, indicating thus their beneficial effect from the corrosion protection viewpoint.
The present investigation has been conducted in order to study the effect of the deposition of a ... more The present investigation has been conducted in order to study the effect of the deposition of a ZrN coating, of ∼3μm in thickness, on the static mechanical properties and fatigue behavior of a 7075-T6 aluminum alloy substrate. It has been determined that the coating deposition process gives rise to a significant decrease in such properties, which is not fully compensated
... Therm. Spray Technol. 6 (1997), p. 205. Full Text via CrossRef | View Record in Scopus | Cite... more ... Therm. Spray Technol. 6 (1997), p. 205. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (27). [2] AA Abdel-Samad, AMM El-Bahloul, E. Lugscheider and SA Rassoul, J. Mater. Sci. 35 (2000), p. 3127. Full ...
In order to improve the biocompatibility with the osseous tissue of metallic implants for orthope... more In order to improve the biocompatibility with the osseous tissue of metallic implants for orthopedic and maxillofacial surgery, these were coated with calcium phosphate (CaP) bioceramics such as Hydroxyapatite (HAp). Electrochemical deposition (ED) has attracted considerable attention due to the number of advantages like coating method over the generally used plasma spray technique. This research evaluates the influence of processing parameters, current density and substrate superficial treatment on the microstructure, adhesion and corrosion resistance of ED-HAp coatings. The thickness, structure and composition of the coatings were investigated by X-ray diffraction (XRD), and scanning electron microscopy (SEM). Impedance Spectroscopy was used to evaluate the adhesion and corrosion resistance of coatings and their dependence on fabrication parameters. The results showed that the thickness increase with the applied deposition current density. The potential vs time curves showed that the Calcium Phosphate deposition progresses with the initial reduction on the alloy surface oxide layer where reduction of nitrate ions takes place on the active free surface sites. The kinetics of this process is enhanced by sufficiently high current densities. Such current densities have a direct influence on the local pH of the solution and determine the morphology, structure and composition of ED-HAp deposited.
Una protesis total de cadera es un implante utilizado en el reemplazo total de la cadera en caso ... more Una protesis total de cadera es un implante utilizado en el reemplazo total de la cadera en caso de lesiones traumaticas o degenerativas. El presente trabajo tiene como objetivo determinar la causa de la falla de una protesis total de cadera en un paciente que presento dolor e impotencia articular manifiesta. Con tal fin se aplico la metodologia caracteristica de un analisis de falla: analisis quimico, estudio metalografico de cabeza y vastago, evaluacion por microscopia electronica de barrido de la superficie fallada y microanalisis quimico por energia dispersiva (EDAX). En la realizacion del analisis medico del caso se consideraron aspectos tales como: tiempo de permanencia del implante en el paciente antes de la falla, actividades realizadas por el paciente, tipo de lesion que amerito el implante, edad, otros. Adicionalmente se realizo un estudio anatomopatologico en los tejidos circundantes al vastago por evidente presencia de metal. El estudio anatomopatologico revelo una fuert...
En estudios realizados sobre la utilizacion de los implantes metalicos que se utilizan en cirugia... more En estudios realizados sobre la utilizacion de los implantes metalicos que se utilizan en cirugia ortopedica traumatologica en Venezuela, se concluye que un elevado numero de casos fallan antes del tiempo de su vida util. Esto trae como consecuencia molestias para el paciente, porque se necesita una nueva intervencion para extraer el implante y colocar uno nuevo, perdidas de horas/hombre en pacientes en etapa laboral y en los medicos, asi como perdida de recursos materiales. En el presente trabajo se muestran los resultados del analisis de falla de dos casos de implantes utilizados en cirugia ortopedica y traumatologica en Venezuela. La metodologia utilizada contemplo la realizacion de analisis quimicos, estudios metalograficos, analisis fractograficos por microscopia electronica de barrido y microanalisis quimico por energia dispersiva (EDAX) En la realizacion del analisis medico se consideraron tecnicas quirurgicas defectuosas de implantacion, tiempo de permanencia del implante en...
Tungsten carbide WC-based composites are widely used in various wear applications requiring a com... more Tungsten carbide WC-based composites are widely used in various wear applications requiring a combination of high toughness, high hardness, and good strength. Some researchers have demonstrated that WC-Co coatings with WC particles in the nanoscale range offer improved properties over their conventional counterparts. This work examines the performance of such conventional and nanostructured materials in the form of coatings deposited by high velocity oxy-fuel (HVOF) thermal spraying. The optimal deposition parameters of nanocomposite powders of WC-12%Co were previously determined. The performance of the coatings was examined under abrasion and sliding conditions. Improvements in mechanical properties and wear resistance were obtained from the nanocomposite coating and the results were attributed to more retained WC and consequently a lower amount of non-WC phases whose presence is detrimental to wear resistance. Also was found that the hardness and fracture toughness of the coatings...
ABSTRACT WC-Co is widely used as a tribological coating material providing a combination of high ... more ABSTRACT WC-Co is widely used as a tribological coating material providing a combination of high toughness, high hardness, and good strength. Herein, an attempt has been made to further enhance the mechanical and wear properties of tungsten carbide cobalt coatings by reinforcing them with multi wall carbon nanotubes (CNTs) using thermal spraying. In this work, 0.35 wt.% of CNTs were mixed by jar-milling in ethanol solution with WC-12%Co microcrystalline powders for different blending times. The mixture was thermally sprayed using the HVOF process onto a plain steel substrate. Also, coatings deposited with both WC-12%Co microcrystalline and nanostructured powders, using the same thermal spray process, were evaluated and compared with samples reinforced with CNTs. The microstructures of the coatings were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Raman Spectroscopy and X-ray diffraction (XRD). The microhardness was measured by Vickers indentation and the abrasive wear resistance was evaluated using a dry sand rubber wheel technique according to ASTM G-65-00 standard. Effects of blending times of CNTs on the microstructure, abrasion wear and microhardness of the coatings were investigated. Experimental results shown that 36 hours of milling time was suitable to disperse CNTs with WC-Co feed powders since it produces an adequate relationship between CNTs´ dispersion time and particle size which enhances the microhardness and porosity of the coatings. The C-36 coating showed an increase in wear resistance of almost 80% and 70% compared with conventional and nanostructured coatings, respectively. This was attributed to the CNTs acting as bridges, promoting the cohesion between lamellas and reducing the decarburization. All reinforced coatings showed a higher abrasive wear resistance than non-reinforced indicating that CNTs are a good alternative to improve abrasion wear resistance of WC-Co coatings.
IOP Conference Series: Materials Science and Engineering, 2013
The present work shows the analysis of a sandblasting process using alumina abrasive particles on... more The present work shows the analysis of a sandblasting process using alumina abrasive particles on Ti-6Al-4V surfaces. The metallic samples were first characterized by optical microscopy (OM), revealing an α+β microstructure with a Widmanstatten morphology. Topography of the samples was assessed by scanning electron microscopy (SEM), before and after sandblasting. The Al2O3 particles used had a granulometric distribution between 420 and 850 μm, with a median particle size (d50) of 670 μm, which decreased to 420 μm after sandblasting for 10 seconds. This change in the size of the particles generated a loss on particle kinetic energy by a factor of 3.5. Such variation on processing conditions induced a progressive increase on average roughness (Ra) of the Ti-6Al-4V surfaces, until the first 7 seconds were reached. From that point on, a reverse process was observed, exerting a polishing effect on the surface of the Ti-6Al-4V alloy.
This paper proposes to evaluate and characterize the damage produced by electrochemical corrosion... more This paper proposes to evaluate and characterize the damage produced by electrochemical corrosion in AISI/SAE 1045 medium carbon steel surfaces, modified with titanium and titanium+nitrogen ions by three-dimensional ion implantation technique. By means of electrochemical tests such as linear polarization resistance, potentiodynamic polarization, and electrochemical impedance spectroscopy; it was quantified and compared the performance of non-implanted and implanted samples against electrochemical corrosion. From the results, it was found a considerable improvement in the performance of the surface-modified ferrous alloy in comparison with bare specimens. The degradation occurred after exposition in the saline environment was reduced up to 50% in terms of mass-loss or corrosion rates. Likewise, the inspection of the state and composition of AISI/SAE 1045 medium carbon steel microstructure, after the surface modification and chemical attack, by microscopy and spectroscopy characteriza...
The resistance to abrasive wear of two hardfacing alloys containing either high Cr or high W was ... more The resistance to abrasive wear of two hardfacing alloys containing either high Cr or high W was studied. The alloys were deposited onto AISI A36 steel plates by a SMAW procedure. An alloy applied by oxyacetylene welding was used as comparison material. Wear resistance was measured in a dry sand – rubber wheel testing machine according to ASTM G65 standard, procedure A. The worn surfaces and the microstructure of the samples were analyzed in optical and scanning electron microscope, while the hardness of the deposits was measured in a Rockwell hardness tester. The best abrasion resistance was obtained in microstructures composed of primary (Fe,Cr)7C3 carbides and eutectic matrix, while higher mass losses were measured in Fe-Cr-C specimens containing primary austenite. The FeW-C hardfacing also showed good abrasion resistance due to the high hardness and deformability of the structure.
The objective of this work was to characterize the corrosive deterioration of the galvanizedcompo... more The objective of this work was to characterize the corrosive deterioration of the galvanizedcomponents of assembly of the structure of an electrical power transmission tower. For this, a visualinspection accompanied by a metallographic analysis, thickness measurement of the galvanized,morphological analysis by scanning electron microscopy (SEM) with chemical microanalysisby dispersive energy (EDX) was carried out. The results obtained show that the metal components evaluated have two clearly differentiable zones in terms of surface tonality: a clear and a dark zone, which indicates the presence of a preferential corrosive deterioration of the coating. The microanalysis by EDX carried out in these zones shows that the damage by corrosion and the consequent loss of thickness of the zinc protective coating of the evaluated components is associated with the presence of atmospheric pollutants. It is concluded that the capacity of protection against corrosion of the galvanized remaining i...
Revista Latinoamericana de Metalurgia y Materiales
The thermal sprayed WC-Co coatings are commonly used in industrial applications in which wear res... more The thermal sprayed WC-Co coatings are commonly used in industrial applications in which wear resistance is needed. Nevertheless, the coatings often present certain problems like not melting or semi-molten particles, poor adhesion to the substrate, low cohesion between particles amongst each other, which could affect the behavior of the coatings. The aim of this work is to investigate the effect of the oxyacetylene flame post heat treatment on the wear resistance of a WCCo- NiCrBSi coating thermally sprayed using a high velocity oxy-fuel (HVOF) process on an AISI 1020 steel substrate. The wear behavior of the coatings with and without post heat treatment was evaluated by erosion test, rubber wheel tests and pin-on-disk tests. It was determined that the abrasion resistance of the post heat treated coatings increased 67% compared with the sample without treatment, which could be attributed to a less porosity, matrix hardening and better cohesion between the hard particles produced by ...
Journal of Applied Biomaterials & Functional Materials, 2015
Background In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most ... more Background In this work, chitosan (CH) was used to produce a novel coating for Ti6Al4V, the most widely used alloy in orthopedic implants, so as to improve the biological tissue response at the metallic surface. Methods The Ti6Al4V surface was sandblasted with alumina particles. CH was chemically modified, via carbodiimide chemistry, using lactobionic and 4-azidebenzoic acid to make it soluble at physiological pH and photocrosslinkable, respectively. The reaction was verified by FTIR, NMR and UV/vis spectroscopy. Ti6Al4V surfaces were coated with solutions of the modified CH and exposed to UV light, causing polymer crosslinking and formation of a hydrogel on the surface. The crosslinking reaction was monitored by FTIR at different exposure times. Coating morphology was observed by SEM. The coating's cytocompatibility was determined in vitro through the culture of rat bone marrow mesenchymal stem cells, using an MTT assay, with their morphology assessed by SEM. Results The develo...
ABSTRACT The present study has been carried out to evaluate the corrosion performance of three di... more ABSTRACT The present study has been carried out to evaluate the corrosion performance of three different (Ti1?xAlx)N/TiN multilayers coatings commercially deposited on WC?Co inserts. Two of these coatings were nanostructured, and all of them presented different Ti/Al atomic ratios varying from 2 : 3 up to 7 : 3 and were deposited by employing a commercial physical vapour deposition cathodic arc process. X-ray diffraction analysis indicated that the grain size for both the TiAlN and TiN layers in the coatings architecture, varied between approximately 9 to 14 nm. The corrosion performance was evaluated in a 3 wt-%NaCl solution using both open circuit potential and potentiodynamic polarisation measurements. Scanning electron microscopy and energy dispersive spectroscopy surface characterisation before and after corrosion testing allowed the determination that all the coatings under study show a corrosion current density of approximately one order of magnitude smaller than the uncoated substrate, indicating thus their beneficial effect from the corrosion protection viewpoint.
The present investigation has been conducted in order to study the effect of the deposition of a ... more The present investigation has been conducted in order to study the effect of the deposition of a ZrN coating, of ∼3μm in thickness, on the static mechanical properties and fatigue behavior of a 7075-T6 aluminum alloy substrate. It has been determined that the coating deposition process gives rise to a significant decrease in such properties, which is not fully compensated
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