Brendy Rincon Troconis - Academia.edu (original) (raw)
Papers by Brendy Rincon Troconis
Corrosion Reviews
With the goal of preventing concrete deterioration by means of destructive corrosion processes, t... more With the goal of preventing concrete deterioration by means of destructive corrosion processes, the use of single organic compounds or mixtures as organic corrosion inhibitors (OCIs) instead of inorganic chemicals is becoming a very attractive practice. As OCIs are more ecologically friendly in their production and environmental fate, they have several advantages over well-known inorganic additives such as metallic nitrites, chromates, or arsenates. In this article, the application of different single organic compounds (of either natural or synthetic origin) as well as mixtures that have been used to lengthen the lifespan of concrete structures is reviewed. After a small exemplification of the use of single organic compounds bearing amino, hydroxy, formyl, or carboxylic functionalities, the more often used OCIs are reviewed according to their principal functional group. Afterward, the application of compound mixtures of either synthetic or natural origin, the use of natural extracts...
Characterizing the Adhesion Between Thin Films and Rigid Substrates Using Digital Image Correlation-Informed Inverse Finite Elements and the Blister Test
Journal of Applied Mechanics
Characterizing the adhesion between thin films and rigid substrates is crucial in engineering app... more Characterizing the adhesion between thin films and rigid substrates is crucial in engineering applications. Still, existing standard methods suffer from issues such as poor reproducibility, difficulties in quantifying adhesion parameters, or overestimation of adhesion strength and fracture energy. Recent studies have shown that the blister test (BT) is a superior method for characterizing adhesion, as it provides a quantifiable measurement of mix-mode fracture energy, and it is highly reproducible. In this paper, we present a novel method to characterize mechanical mix-mode adhesion between thin films and rigid substrates using the BT. Our method combines the full triaxial displacement field obtained through digital image correlation with inverse finite element method simulations using cohesive zone elements. This approach eliminates the need for making any mechanistic or kinematic assumptions of the blister formation and allows the characterization of the full traction-separation l...
Corrosion-Resistant Stainless-Steel Strands for Prestressed Bridge Piles in Marine Atmospheric Environments
Corrosion
This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits ... more This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits superior corrosion resistance when compared to stranded cold-worked AISI 1080 (ASTM A416) steel and cold-worked modified austenitic stainless steel 201, making it a viable candidate for prestressing applications with extended service life. Laboratory and field testing were performed. The material microstructure was characterized using scanning electron microscopy/energy dispersive x-ray spectroscopy, transmission electron microscopy, and x-ray diffraction. Then, laboratory corrosion testing, including linear sweep voltammetry, pitting resistance exposure, and four-point bend stress corrosion cracking (SCC) testing, was performed under different conditions. These conditions included concrete pore solution saturated with chlorides, direct exposure to artificial seawater, various concentrations of NaCl and MgCl2, representative inland salt deposition conditions, and oxidizing conditions wit...
Artificial neural network model to estimate the long-term carbonation depth of concrete exposed to natural environments
Journal of building engineering, Apr 1, 2023
An Optimized Polarization Model for Anode-Supported Solid Oxide Fuel Cells
AIChE Annual Meeting, 2020
Advances in Coating Adhesion Testing Using the Blister Test, Digital Image Correlation and Finite Element Methods
ECS Meeting Abstracts
Adhesively bonded aluminum joints are widely used in multiple engineering sectors, especially the... more Adhesively bonded aluminum joints are widely used in multiple engineering sectors, especially the automotive industry. In long-term service, environmental conditions and stresses caused by factors such as internal deformation, residual stresses, or corrosion, cause adhesion strength degradation. Quantifying the adhesion strength is a complex task. While many different adhesion tests are available, the Blister Test (BT) is the only one that provides a measure of the normalized energy required to initiate and propagate a crack at the polymer/substrate interface. The adhesion strength of coatings on aluminum substrate for automotive applications was investigated using the Blister Test (BT) along with Digital Image Correlation (DIC), and Finite Element Methods (FEM). The BT was performed by pressurizing a fluid through a hole in the substrate, which causes blistering on the coating, ultimately leading to delamination. This test is performed after exposure of samples to an accelerated co...
Effect of microstructure on the pitting susceptibility of a martensitic-ferritic stainless steel: A corrosion-metallurgical study
Corrosion Science, 2022
(Invited) In-Situ Spectroelectrochemical Evaluation of Stress Corrosion Cracking of Carbon Steel in H2s/CO2 Environment in Presence of H2s Scavenger
ECS Meeting Abstracts, 2020
Injecting H2S scavenger is a common practice to reduce H2S. However, failures in the form of SCC ... more Injecting H2S scavenger is a common practice to reduce H2S. However, failures in the form of SCC of steel pipes have been reported. There is no knowledge about the effects of this chemistry on the corrosion and cracking mechanism of carbon steel. Based on literature related to corrosion in bicarbonate containing environments and the results of this work, it is suggested that SCC is governed by a possible transition from passive to active kinetics. This transition is a complicated function of gas concentration and amine adsorption. In this work, in-situ Raman spectroscopy was used to identify the chemical species present in the test solution prior to and following the scavenging process. In-situ surface enhanced Raman spectroscopy was utilized to measure specific adsorption of amine by-products on the steel, as well as, changes in the surface film composition. Electrochemical techniques (linear polarization resistance, potentiodynamic polarization, and electrochemical impedance spect...
Effects of Triazine-Based H 2 S Scavengers Byproducts on the Film Composition and Cracking of Carbon Steel in Oilfield Applications
Corrosion, 2019
Energies, 2020
This research consists of both theoretical and experimental sections presenting a novel scenario ... more This research consists of both theoretical and experimental sections presenting a novel scenario for the consumption of hydrogen in the polymer electrolyte membrane fuel cell (PEMFC). In the theory section, a new correction factor called parameter δ is used for the calculation of fuel utilization by introducing concepts of “useful water” and “non-useful water”. The term of “useful water” refers to the state that consumed hydrogen leads to the production of liquid water and external electric current. In the experimental section, the effect of the relative humidity of the cathode side on the performance and power density is investigated by calculating the parameter δ and the modified fuel utilization at 50% and 80% relative humidity. Based on the experimental results, the maximum power density obtained at 50% and 80% relative humidity of the cathode side is about 645 mW/cm2 and 700 mW/cm2, respectively. On the other hand, the maximum value of parameter δ for a value of 50% relative hu...
ECS Meeting Abstracts, 2012
![Research paper thumbnail of {"__content__"=>"Time-dependent Enhanced Corrosion of Ti6Al4V in the Presence of HOand Albumin.", "sub"=>[{"__content__"=>"2"}, {"__content__"=>"2"}]}](https://attachments.academia-assets.com/96792433/thumbnails/1.jpg)
](Scientific reports, Jan 16, 2018
There is increasing concern regarding the biological consequences of metal release from implants.... more There is increasing concern regarding the biological consequences of metal release from implants. However, the mechanisms underpinning implant surface degradation, especially in the absence of wear, are often poorly understood. Here the synergistic effect of albumin and HOon corrosion of Ti6Al4V in physiological saline is studied with electrochemical methods. It is found that albumin induces a time-dependent dissolution of Ti6Al4V in the presence of HOin physiology saline. Potentiostatic polarisation measurements show that albumin supresses dissolution in the presence of HOat short times (<24 h) but over longer time periods (120 h) it significantly accelerates corrosion, which is attributed to albumin-catalysed dissolution of the corrosion product layer resulting in formation of a thinner oxide film. Dissolution of Ti6Al4V in the presence of albumin and HOin physiological saline is also found to be dependent on potential: the titanium ion release rate is found to be higher (0.57 ...
Blister Test for Measurements of Adhesion and Adhesion Degradation of Organic Polymers on AA2024-T3
Metallurgical and Materials Transactions A, 2016
The influence of microstructural variation on hydrogen environment-assisted cracking (HEAC) of Mo... more The influence of microstructural variation on hydrogen environment-assisted cracking (HEAC) of Monel K-500 was evaluated using five nominally peak-aged lots of material tested under slow-rising stress intensity loading while immersed in NaCl solution under cathodic polarizations. Minimal variation in HEAC resistance among material lots was observed for an applied potential of À950 mV SCE (E app , vs saturated calomel), whereas lot-to-lot variability in the fracture morphology demonstrates a significant difference in the HEAC resistance at the less negative potential of À850 mV SCE , suggesting that relatively severe H environments produce sufficient crack-tip H to minimize the impact of metallurgical differences. Sensitivity analyses accomplished by varying the inputs used in decohesion-based, micromechanical models imply significant variations in HEAC resistance are possible for realistic changes in grain boundary toughness, hydrogen uptake behavior, and yield strength. Grain size, impurity segregation (including the effects of gettering elements), grain boundary character/connectivity, and crack path tortuosity are also considered in the context of HEAC susceptibility. Yield strength, global hydrogen content, as well as impurity segregation to grain boundaries, especially boron and sulfur, are speculatively considered to be the dominant contributions in determining HEAC resistance. Modifications that would incorporate the effects of grain boundary segregation are proposed for the K TH model; detailed validation of such changes require high-fidelity and quantitative inputs for the degree of grain boundary segregation. Regardless, fracture mechanics-based HEAC results, detailed microstructural characterization, and micromechanical modeling were successfully coupled to gain insights into the influences governing the microstructure-dependent HEAC susceptibility of Monel K-500.
ECS Transactions, 2014
Copper, silver and gold films possess unique electrical and optical properties that render them s... more Copper, silver and gold films possess unique electrical and optical properties that render them suitable for various device structures as employed in integrated circuits and plasmonic devices. Traditional etching of these metal films in halogenated plasmas is difficult due to the low vapor pressure of halogenated metal species. Reasonable etch rates of Cu, Ag, and Au films are obtained with hydrogen-based plasmas. Pattern formation with hydrogen and methane plasmas yields excellent selectivity to barrier materials such as Ta and Ti and generates metal wall slopes of ~80o.
Surface and Coatings Technology, 2013
Corrosion protection through protective coatings depends on the adhesion of the coating system to... more Corrosion protection through protective coatings depends on the adhesion of the coating system to the base metal, which is controlled by surface treatments. Measuring adhesion strength is a challenging task. However, the Blister Test (BT) is a quantitative and reproducible technique not exploited in the corrosion field. In this investigation, the effect of roughness and surface topography is studied using this technique. Samples were abraded using SiC paper up to 120, 180, 600 and 1200 in a randomly or aligned manner to obtain different topographies and roughness levels in the range of 0.026 to 1.324 μm. The surfaces were characterized using Optical Profilometry before polyvinyl butyral (PVB) coating was applied. Then the adhesion strength was determined using the BT. The substrates abraded randomly presented lower average roughness than the ones abraded in an aligned manner due to continual cross abrasion of grooves. The adhesion strength results from the BT were reproducible and could rank different mechanical treatments. Roughness degree and surface topography were found to be very important factors for adhesion strength. Adhesion strength was found to increase with roughness for both abrasion methods; however the random samples exhibited the highest adhesion strength at similar roughness values. The groove peaks were found to be stronger barriers than the groove valleys as a result of a higher peeling angle needed for delamination to take place, increasing the energy used for plastic deformation and therefore decreasing the energy available for blister growth. An adhesion strength indicator (AS) was defined based on peeling rate and found to be effective in sensing adhesion strength.
Progress in Organic Coatings, 2014
The effects of multiwalled carbon nanotube (MWCNT) content on the adhesion strength and wear and ... more The effects of multiwalled carbon nanotube (MWCNT) content on the adhesion strength and wear and corrosion resistance of the epoxy composite coatings prepared on aluminum alloy (AA) 2024-T3 substrates were evaluated using atomic force microscopy (AFM), blister test, ball-on-disk micro-tribological test and electrochemical impedance spectroscopy (EIS). The adhesion strength of the epoxy composite coatings improved with increasing MWCNT content. Increased MWCNT content also decreased the friction coefficient and increased the wear resistance of the epoxy composite coatings due to improved solid lubricating and rolling effects of the MWCNTs and the improved load bearing capacity of the composite coatings. Finally, EIS indicated that increased MWCNT content increased the coating pore resistance due to a decreased porosity density, which resulted in an increase in the total impedance of the coated samples.
Effects of Pretreatments on the Adhesion of Acetoacetate to AA2024-T3 Using the Blister Test
CORROSION, 2014
ABSTRACT
Corrosion, 2013
A test sample incorporating a coated and scribed Al alloy panel and uncoated through-hole fastene... more A test sample incorporating a coated and scribed Al alloy panel and uncoated through-hole fasteners was designed to provide accelerated response during atmospheric corrosion testing in the field or in laboratory chambers. Protective coatings that would take many months to show signs of degradation on normal scribed samples with no galvanic connection exhibited corrosion in much shorter times when uncoated Ti alloy or stainless steel fasteners were used, particularly in conjunction with scribes through the coating. The results after three weeks of exposure to ASTM B117 correlated well with long-term beach exposure, allowing rapid ranking of different coating systems. Of the fastener materials studied, visual observation indicated that the worst attack occurred near Type 316 (UNS S31600) stainless steel (SS316) fasteners even though Ti-6Al-4V fasteners are more noble. The volume of AA2024-T3 (UNS A92024) lost during the exposure, as determined by an optical profilometer, was also larg...
Corrosion
The effectiveness of 1-benzyl-4-phenyl-1H-1,2,3-triazole (BPT) was evaluated as a potential green... more The effectiveness of 1-benzyl-4-phenyl-1H-1,2,3-triazole (BPT) was evaluated as a potential green organic corrosion inhibitor to reduce the effects of corrosion on the reinforcing steel in concrete. The BPT inhibitor was assessed in synthetic pore solution (SPS, 8.33 g/L of NaOH + 23.3 g/L of KOH + 2.0 g/L of Ca(OH)<sub>2</sub>, pH = 13.6) in presence of 2 M NaCl and following a carbonation free and rebar passivation stabilization protocol prior Cl<sup>-</sup> addition, similar to ASTM G180. A base solution (2.35 mg/mL) of BPT in N-methyl-2-pyrrolidone (NMP) was prepared due to the limited solubility of BPT in water. Electrochemical techniques including open circuit potential, linear polarization resistance, Electrochemical Impedance Spectroscopy (EIS) and cyclic polarization curves were conducted to assess the performance of the inhibitor. The results showed that the inhibitor effectively reduces the corrosion rate of the steel rebar. The BPT optimal concent...
Corrosion Reviews
With the goal of preventing concrete deterioration by means of destructive corrosion processes, t... more With the goal of preventing concrete deterioration by means of destructive corrosion processes, the use of single organic compounds or mixtures as organic corrosion inhibitors (OCIs) instead of inorganic chemicals is becoming a very attractive practice. As OCIs are more ecologically friendly in their production and environmental fate, they have several advantages over well-known inorganic additives such as metallic nitrites, chromates, or arsenates. In this article, the application of different single organic compounds (of either natural or synthetic origin) as well as mixtures that have been used to lengthen the lifespan of concrete structures is reviewed. After a small exemplification of the use of single organic compounds bearing amino, hydroxy, formyl, or carboxylic functionalities, the more often used OCIs are reviewed according to their principal functional group. Afterward, the application of compound mixtures of either synthetic or natural origin, the use of natural extracts...
Characterizing the Adhesion Between Thin Films and Rigid Substrates Using Digital Image Correlation-Informed Inverse Finite Elements and the Blister Test
Journal of Applied Mechanics
Characterizing the adhesion between thin films and rigid substrates is crucial in engineering app... more Characterizing the adhesion between thin films and rigid substrates is crucial in engineering applications. Still, existing standard methods suffer from issues such as poor reproducibility, difficulties in quantifying adhesion parameters, or overestimation of adhesion strength and fracture energy. Recent studies have shown that the blister test (BT) is a superior method for characterizing adhesion, as it provides a quantifiable measurement of mix-mode fracture energy, and it is highly reproducible. In this paper, we present a novel method to characterize mechanical mix-mode adhesion between thin films and rigid substrates using the BT. Our method combines the full triaxial displacement field obtained through digital image correlation with inverse finite element method simulations using cohesive zone elements. This approach eliminates the need for making any mechanistic or kinematic assumptions of the blister formation and allows the characterization of the full traction-separation l...
Corrosion-Resistant Stainless-Steel Strands for Prestressed Bridge Piles in Marine Atmospheric Environments
Corrosion
This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits ... more This study demonstrated that stranded highly cold-worked 2205 stainless steel (SCW2205) exhibits superior corrosion resistance when compared to stranded cold-worked AISI 1080 (ASTM A416) steel and cold-worked modified austenitic stainless steel 201, making it a viable candidate for prestressing applications with extended service life. Laboratory and field testing were performed. The material microstructure was characterized using scanning electron microscopy/energy dispersive x-ray spectroscopy, transmission electron microscopy, and x-ray diffraction. Then, laboratory corrosion testing, including linear sweep voltammetry, pitting resistance exposure, and four-point bend stress corrosion cracking (SCC) testing, was performed under different conditions. These conditions included concrete pore solution saturated with chlorides, direct exposure to artificial seawater, various concentrations of NaCl and MgCl2, representative inland salt deposition conditions, and oxidizing conditions wit...
Artificial neural network model to estimate the long-term carbonation depth of concrete exposed to natural environments
Journal of building engineering, Apr 1, 2023
An Optimized Polarization Model for Anode-Supported Solid Oxide Fuel Cells
AIChE Annual Meeting, 2020
Advances in Coating Adhesion Testing Using the Blister Test, Digital Image Correlation and Finite Element Methods
ECS Meeting Abstracts
Adhesively bonded aluminum joints are widely used in multiple engineering sectors, especially the... more Adhesively bonded aluminum joints are widely used in multiple engineering sectors, especially the automotive industry. In long-term service, environmental conditions and stresses caused by factors such as internal deformation, residual stresses, or corrosion, cause adhesion strength degradation. Quantifying the adhesion strength is a complex task. While many different adhesion tests are available, the Blister Test (BT) is the only one that provides a measure of the normalized energy required to initiate and propagate a crack at the polymer/substrate interface. The adhesion strength of coatings on aluminum substrate for automotive applications was investigated using the Blister Test (BT) along with Digital Image Correlation (DIC), and Finite Element Methods (FEM). The BT was performed by pressurizing a fluid through a hole in the substrate, which causes blistering on the coating, ultimately leading to delamination. This test is performed after exposure of samples to an accelerated co...
Effect of microstructure on the pitting susceptibility of a martensitic-ferritic stainless steel: A corrosion-metallurgical study
Corrosion Science, 2022
(Invited) In-Situ Spectroelectrochemical Evaluation of Stress Corrosion Cracking of Carbon Steel in H2s/CO2 Environment in Presence of H2s Scavenger
ECS Meeting Abstracts, 2020
Injecting H2S scavenger is a common practice to reduce H2S. However, failures in the form of SCC ... more Injecting H2S scavenger is a common practice to reduce H2S. However, failures in the form of SCC of steel pipes have been reported. There is no knowledge about the effects of this chemistry on the corrosion and cracking mechanism of carbon steel. Based on literature related to corrosion in bicarbonate containing environments and the results of this work, it is suggested that SCC is governed by a possible transition from passive to active kinetics. This transition is a complicated function of gas concentration and amine adsorption. In this work, in-situ Raman spectroscopy was used to identify the chemical species present in the test solution prior to and following the scavenging process. In-situ surface enhanced Raman spectroscopy was utilized to measure specific adsorption of amine by-products on the steel, as well as, changes in the surface film composition. Electrochemical techniques (linear polarization resistance, potentiodynamic polarization, and electrochemical impedance spect...
Effects of Triazine-Based H 2 S Scavengers Byproducts on the Film Composition and Cracking of Carbon Steel in Oilfield Applications
Corrosion, 2019
Energies, 2020
This research consists of both theoretical and experimental sections presenting a novel scenario ... more This research consists of both theoretical and experimental sections presenting a novel scenario for the consumption of hydrogen in the polymer electrolyte membrane fuel cell (PEMFC). In the theory section, a new correction factor called parameter δ is used for the calculation of fuel utilization by introducing concepts of “useful water” and “non-useful water”. The term of “useful water” refers to the state that consumed hydrogen leads to the production of liquid water and external electric current. In the experimental section, the effect of the relative humidity of the cathode side on the performance and power density is investigated by calculating the parameter δ and the modified fuel utilization at 50% and 80% relative humidity. Based on the experimental results, the maximum power density obtained at 50% and 80% relative humidity of the cathode side is about 645 mW/cm2 and 700 mW/cm2, respectively. On the other hand, the maximum value of parameter δ for a value of 50% relative hu...
ECS Meeting Abstracts, 2012
Scientific reports, Jan 16, 2018
There is increasing concern regarding the biological consequences of metal release from implants.... more There is increasing concern regarding the biological consequences of metal release from implants. However, the mechanisms underpinning implant surface degradation, especially in the absence of wear, are often poorly understood. Here the synergistic effect of albumin and HOon corrosion of Ti6Al4V in physiological saline is studied with electrochemical methods. It is found that albumin induces a time-dependent dissolution of Ti6Al4V in the presence of HOin physiology saline. Potentiostatic polarisation measurements show that albumin supresses dissolution in the presence of HOat short times (<24 h) but over longer time periods (120 h) it significantly accelerates corrosion, which is attributed to albumin-catalysed dissolution of the corrosion product layer resulting in formation of a thinner oxide film. Dissolution of Ti6Al4V in the presence of albumin and HOin physiological saline is also found to be dependent on potential: the titanium ion release rate is found to be higher (0.57 ...
Blister Test for Measurements of Adhesion and Adhesion Degradation of Organic Polymers on AA2024-T3
Metallurgical and Materials Transactions A, 2016
The influence of microstructural variation on hydrogen environment-assisted cracking (HEAC) of Mo... more The influence of microstructural variation on hydrogen environment-assisted cracking (HEAC) of Monel K-500 was evaluated using five nominally peak-aged lots of material tested under slow-rising stress intensity loading while immersed in NaCl solution under cathodic polarizations. Minimal variation in HEAC resistance among material lots was observed for an applied potential of À950 mV SCE (E app , vs saturated calomel), whereas lot-to-lot variability in the fracture morphology demonstrates a significant difference in the HEAC resistance at the less negative potential of À850 mV SCE , suggesting that relatively severe H environments produce sufficient crack-tip H to minimize the impact of metallurgical differences. Sensitivity analyses accomplished by varying the inputs used in decohesion-based, micromechanical models imply significant variations in HEAC resistance are possible for realistic changes in grain boundary toughness, hydrogen uptake behavior, and yield strength. Grain size, impurity segregation (including the effects of gettering elements), grain boundary character/connectivity, and crack path tortuosity are also considered in the context of HEAC susceptibility. Yield strength, global hydrogen content, as well as impurity segregation to grain boundaries, especially boron and sulfur, are speculatively considered to be the dominant contributions in determining HEAC resistance. Modifications that would incorporate the effects of grain boundary segregation are proposed for the K TH model; detailed validation of such changes require high-fidelity and quantitative inputs for the degree of grain boundary segregation. Regardless, fracture mechanics-based HEAC results, detailed microstructural characterization, and micromechanical modeling were successfully coupled to gain insights into the influences governing the microstructure-dependent HEAC susceptibility of Monel K-500.
ECS Transactions, 2014
Copper, silver and gold films possess unique electrical and optical properties that render them s... more Copper, silver and gold films possess unique electrical and optical properties that render them suitable for various device structures as employed in integrated circuits and plasmonic devices. Traditional etching of these metal films in halogenated plasmas is difficult due to the low vapor pressure of halogenated metal species. Reasonable etch rates of Cu, Ag, and Au films are obtained with hydrogen-based plasmas. Pattern formation with hydrogen and methane plasmas yields excellent selectivity to barrier materials such as Ta and Ti and generates metal wall slopes of ~80o.
Surface and Coatings Technology, 2013
Corrosion protection through protective coatings depends on the adhesion of the coating system to... more Corrosion protection through protective coatings depends on the adhesion of the coating system to the base metal, which is controlled by surface treatments. Measuring adhesion strength is a challenging task. However, the Blister Test (BT) is a quantitative and reproducible technique not exploited in the corrosion field. In this investigation, the effect of roughness and surface topography is studied using this technique. Samples were abraded using SiC paper up to 120, 180, 600 and 1200 in a randomly or aligned manner to obtain different topographies and roughness levels in the range of 0.026 to 1.324 μm. The surfaces were characterized using Optical Profilometry before polyvinyl butyral (PVB) coating was applied. Then the adhesion strength was determined using the BT. The substrates abraded randomly presented lower average roughness than the ones abraded in an aligned manner due to continual cross abrasion of grooves. The adhesion strength results from the BT were reproducible and could rank different mechanical treatments. Roughness degree and surface topography were found to be very important factors for adhesion strength. Adhesion strength was found to increase with roughness for both abrasion methods; however the random samples exhibited the highest adhesion strength at similar roughness values. The groove peaks were found to be stronger barriers than the groove valleys as a result of a higher peeling angle needed for delamination to take place, increasing the energy used for plastic deformation and therefore decreasing the energy available for blister growth. An adhesion strength indicator (AS) was defined based on peeling rate and found to be effective in sensing adhesion strength.
Progress in Organic Coatings, 2014
The effects of multiwalled carbon nanotube (MWCNT) content on the adhesion strength and wear and ... more The effects of multiwalled carbon nanotube (MWCNT) content on the adhesion strength and wear and corrosion resistance of the epoxy composite coatings prepared on aluminum alloy (AA) 2024-T3 substrates were evaluated using atomic force microscopy (AFM), blister test, ball-on-disk micro-tribological test and electrochemical impedance spectroscopy (EIS). The adhesion strength of the epoxy composite coatings improved with increasing MWCNT content. Increased MWCNT content also decreased the friction coefficient and increased the wear resistance of the epoxy composite coatings due to improved solid lubricating and rolling effects of the MWCNTs and the improved load bearing capacity of the composite coatings. Finally, EIS indicated that increased MWCNT content increased the coating pore resistance due to a decreased porosity density, which resulted in an increase in the total impedance of the coated samples.
Effects of Pretreatments on the Adhesion of Acetoacetate to AA2024-T3 Using the Blister Test
CORROSION, 2014
ABSTRACT
Corrosion, 2013
A test sample incorporating a coated and scribed Al alloy panel and uncoated through-hole fastene... more A test sample incorporating a coated and scribed Al alloy panel and uncoated through-hole fasteners was designed to provide accelerated response during atmospheric corrosion testing in the field or in laboratory chambers. Protective coatings that would take many months to show signs of degradation on normal scribed samples with no galvanic connection exhibited corrosion in much shorter times when uncoated Ti alloy or stainless steel fasteners were used, particularly in conjunction with scribes through the coating. The results after three weeks of exposure to ASTM B117 correlated well with long-term beach exposure, allowing rapid ranking of different coating systems. Of the fastener materials studied, visual observation indicated that the worst attack occurred near Type 316 (UNS S31600) stainless steel (SS316) fasteners even though Ti-6Al-4V fasteners are more noble. The volume of AA2024-T3 (UNS A92024) lost during the exposure, as determined by an optical profilometer, was also larg...
Corrosion
The effectiveness of 1-benzyl-4-phenyl-1H-1,2,3-triazole (BPT) was evaluated as a potential green... more The effectiveness of 1-benzyl-4-phenyl-1H-1,2,3-triazole (BPT) was evaluated as a potential green organic corrosion inhibitor to reduce the effects of corrosion on the reinforcing steel in concrete. The BPT inhibitor was assessed in synthetic pore solution (SPS, 8.33 g/L of NaOH + 23.3 g/L of KOH + 2.0 g/L of Ca(OH)<sub>2</sub>, pH = 13.6) in presence of 2 M NaCl and following a carbonation free and rebar passivation stabilization protocol prior Cl<sup>-</sup> addition, similar to ASTM G180. A base solution (2.35 mg/mL) of BPT in N-methyl-2-pyrrolidone (NMP) was prepared due to the limited solubility of BPT in water. Electrochemical techniques including open circuit potential, linear polarization resistance, Electrochemical Impedance Spectroscopy (EIS) and cyclic polarization curves were conducted to assess the performance of the inhibitor. The results showed that the inhibitor effectively reduces the corrosion rate of the steel rebar. The BPT optimal concent...