M. Schorr, B. Valdez, R. Salinas, Rogelio Ramos, N. Nedey, M. Curiel
The combat fields of modern wars, including the struggle against global terrorism, are localized in diverse, harsh regions: tropical, desert, artic, marine, with varied weather conditions, which adversely affect the corrosion performance of the equipment and facilities involved. For the sake of brevity, three groups of military mobile and fixed equipment and structures are dealt with: armored ground wheeled vehicles; naval aluminum vessels, and buildings and facilities for providing dwellings, weapons storage and services to the armed forces. They are usually made from carbon steel, aluminum alloys and reinforced concrete, because of their useful properties: high strength, easy availability and low cost. However, due to their limited corrosion resistance they should be protected by coatings (including military coatings), but primarily paint; cathodic protection and corrosion inhibitors. All these systems suffer from several types of localized corrosion and degradation: galvanic, pitting, intergranular, dealloying, cavitation, erosion, stress cracking, UV effects in plastics and organic coatings. The military assets require the implementation of corrosion control methods and techniques through all their stages: design, construction, installation and operation. Typical cases of corrosion will be presented based on the authors experience and knowledge.
{"title":"Corrosion Control in Military Assets","authors":"M. Schorr, B. Valdez, R. Salinas, Rogelio Ramos, N. Nedey, M. Curiel","doi":"10.1557/OPL.2016.88","DOIUrl":"https://doi.org/10.1557/OPL.2016.88","url":null,"abstract":"The combat fields of modern wars, including the struggle against global terrorism, are localized in diverse, harsh regions: tropical, desert, artic, marine, with varied weather conditions, which adversely affect the corrosion performance of the equipment and facilities involved. For the sake of brevity, three groups of military mobile and fixed equipment and structures are dealt with: armored ground wheeled vehicles; naval aluminum vessels, and buildings and facilities for providing dwellings, weapons storage and services to the armed forces. They are usually made from carbon steel, aluminum alloys and reinforced concrete, because of their useful properties: high strength, easy availability and low cost. However, due to their limited corrosion resistance they should be protected by coatings (including military coatings), but primarily paint; cathodic protection and corrosion inhibitors. All these systems suffer from several types of localized corrosion and degradation: galvanic, pitting, intergranular, dealloying, cavitation, erosion, stress cracking, UV effects in plastics and organic coatings. The military assets require the implementation of corrosion control methods and techniques through all their stages: design, construction, installation and operation. Typical cases of corrosion will be presented based on the authors experience and knowledge.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"5 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87817724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karen Blanco, Víctor Manuel Moo Yam, T. P. López, J. R. L. Jiménez
As is well known, the corrosion of embedded steel reinforced depends strongly of the concrete resistivity, which is related directly with the water contained into its porous network. Environment plays an important role on resistivity, due to have a direct correspondence with the relative humidity and temperature. In these terms, ingress or output of water is favored or hampered by the environmental parameters, as well as its fluctuations. This work presents a proposal of instrumented system to generate a map of electrical resistivity at concrete samples by using superficial and embedded electrodes. Mathematical analysis of equivalent circuit revealed the importance of the impedance of electrodes utilized, to simplify measures. Concrete samples were exposed to different relative humidity focused to try to obtain the relation between relative humidity and resistivity. An array of two electrodes distributed in a matrix was manufactured to apply a signal of direct current at first electrode and measure the resultant current at second electrode. The system applies a programmed sequence of switch to turn on and turn off to realize measurements over established zone and, in this form, allows identify zones with potentials gradients. Also, do easy the monitoring of concrete resistivity evolution in function of time and humidity conditions.
{"title":"Instrumented System for Analysis of Concrete Resistivity","authors":"Karen Blanco, Víctor Manuel Moo Yam, T. P. López, J. R. L. Jiménez","doi":"10.1557/OPL.2016.93","DOIUrl":"https://doi.org/10.1557/OPL.2016.93","url":null,"abstract":"As is well known, the corrosion of embedded steel reinforced depends strongly of the concrete resistivity, which is related directly with the water contained into its porous network. Environment plays an important role on resistivity, due to have a direct correspondence with the relative humidity and temperature. In these terms, ingress or output of water is favored or hampered by the environmental parameters, as well as its fluctuations. This work presents a proposal of instrumented system to generate a map of electrical resistivity at concrete samples by using superficial and embedded electrodes. Mathematical analysis of equivalent circuit revealed the importance of the impedance of electrodes utilized, to simplify measures. Concrete samples were exposed to different relative humidity focused to try to obtain the relation between relative humidity and resistivity. An array of two electrodes distributed in a matrix was manufactured to apply a signal of direct current at first electrode and measure the resultant current at second electrode. The system applies a programmed sequence of switch to turn on and turn off to realize measurements over established zone and, in this form, allows identify zones with potentials gradients. Also, do easy the monitoring of concrete resistivity evolution in function of time and humidity conditions.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"58 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86119377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current work reports the effect of particle size on the rheological behavior of polymer modified asphalt PMA. The modified asphalt was generated with AC-20 asphalt precursor provided by Pemex Salamanca and Solprene® 416 provided by Dynasol Mexico. Solprene® 416 is a SBS star-type copolymer with 4 poly(b-styrene-b-butadiene) arms and Mw = 2.36X105 g/gmole. Modified asphalt samples were prepared with 3 wt % of SBS via hot mix process. Mixing time and temperature were kept constant at 4h and 180 °C. This study also varied the agitation in the mixing process: 500, 1000 and 1500 rpm. All PMAs shown sphere-shaped polymer particles as observed via fluorescent microscopy using a Carl Zeiss KS-300 system. Base asphalt and PMAs were also characterized through rheological measurements using a TA Instruments AR-G2 rheometer. Shear viscosity (η) and tan δ data shown that the flow resistance of the PMA increases as the size its polymer particles decreases. Since the size of the polymer particles decreases with the increase of the stirring speed, it is concluded that the stirring speed of the process determines the size of the polymer particles and so the mechanical resistance of the PMA.
{"title":"Effect of Stirring Speed in Hot Mixing Process of Modified Asphalt with SBS Copolymer on Polymeric Distribution and its Rheological Properties","authors":"E. García, R. H. Nájera","doi":"10.1557/OPL.2016.5","DOIUrl":"https://doi.org/10.1557/OPL.2016.5","url":null,"abstract":"The current work reports the effect of particle size on the rheological behavior of polymer modified asphalt PMA. The modified asphalt was generated with AC-20 asphalt precursor provided by Pemex Salamanca and Solprene® 416 provided by Dynasol Mexico. Solprene® 416 is a SBS star-type copolymer with 4 poly(b-styrene-b-butadiene) arms and Mw = 2.36X105 g/gmole. Modified asphalt samples were prepared with 3 wt % of SBS via hot mix process. Mixing time and temperature were kept constant at 4h and 180 °C. This study also varied the agitation in the mixing process: 500, 1000 and 1500 rpm. All PMAs shown sphere-shaped polymer particles as observed via fluorescent microscopy using a Carl Zeiss KS-300 system. Base asphalt and PMAs were also characterized through rheological measurements using a TA Instruments AR-G2 rheometer. Shear viscosity (η) and tan δ data shown that the flow resistance of the PMA increases as the size its polymer particles decreases. Since the size of the polymer particles decreases with the increase of the stirring speed, it is concluded that the stirring speed of the process determines the size of the polymer particles and so the mechanical resistance of the PMA.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"32 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86720242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-pressure torsion (HPT) is a processing technique in which samples are subjected to a high pressure and torsional straining. Anvil alignment and anvil roughness are two important factors related to the successful application of the HPT processing technique. Using a two-phase duplex stainless steel as a model material, experiments were conducted by placing the anvils in different amounts of initial misalignment. Experiments show that the flow patterns (the development of double-swirl patterns) in HPT are dependent upon the alignment of the anvils within the HPT facility. Through carefully designed experiments, it is shown that the presence of a double-swirl is a feature of HPT processing when the initial positions of the anvils have a small lateral misalignment. The effect of the double-swirl patterns on the hardness evolution was also evaluated quantitatively. By comparing the flow patterns developed on the disc upper surface using both rough and smooth anvils with a fixed anvil misalignment, it was demonstrated that there are some differences in the flow patterns which are dependent upon the anvil surface roughness.
{"title":"Investigating Anvil Alignment and Anvil Roughness on Flow Pattern Development in High-Pressure Torsion","authors":"Yi Huang, M. Kawasaki, T. Langdon","doi":"10.1557/OPL.2016.79","DOIUrl":"https://doi.org/10.1557/OPL.2016.79","url":null,"abstract":"High-pressure torsion (HPT) is a processing technique in which samples are subjected to a high pressure and torsional straining. Anvil alignment and anvil roughness are two important factors related to the successful application of the HPT processing technique. Using a two-phase duplex stainless steel as a model material, experiments were conducted by placing the anvils in different amounts of initial misalignment. Experiments show that the flow patterns (the development of double-swirl patterns) in HPT are dependent upon the alignment of the anvils within the HPT facility. Through carefully designed experiments, it is shown that the presence of a double-swirl is a feature of HPT processing when the initial positions of the anvils have a small lateral misalignment. The effect of the double-swirl patterns on the hardness evolution was also evaluated quantitatively. By comparing the flow patterns developed on the disc upper surface using both rough and smooth anvils with a fixed anvil misalignment, it was demonstrated that there are some differences in the flow patterns which are dependent upon the anvil surface roughness.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"109 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80703534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Single Layer Hafnium Nitride Coated Tool for Metal Cutting","authors":"J. Devia, W. A. Chaparro, J. Lizarazo","doi":"10.1557/OPL.2016.91","DOIUrl":"https://doi.org/10.1557/OPL.2016.91","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81917847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthesis of SBA-15/MCM-41 bimodal mesoporous silica","authors":"L. Jaramillo, W. Henao, E. Pabón-Gelves","doi":"10.1557/OPL.2016.47","DOIUrl":"https://doi.org/10.1557/OPL.2016.47","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80924539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Radámes, J. Mendoza, Z. A. Valderrama, L. Lartundo-Rojas, J. A. Góngora
{"title":"Structural and Optical Properties of Co-doped HfO2 Multi-layer Deposited by Spray Pyrolysis Technique","authors":"R. Radámes, J. Mendoza, Z. A. Valderrama, L. Lartundo-Rojas, J. A. Góngora","doi":"10.1557/OPL.2016.50","DOIUrl":"https://doi.org/10.1557/OPL.2016.50","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90241923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Olarte-Paredes, R. Salgado-Delgado, A. Salgado-Delgado, E. Rubio-Rosas, E. García-Hernández, Z. Vargas-Galarza
{"title":"Superficial and electrical characterization of thin films based on Chitosan/polypyrrole/MWCNT","authors":"A. Olarte-Paredes, R. Salgado-Delgado, A. Salgado-Delgado, E. Rubio-Rosas, E. García-Hernández, Z. Vargas-Galarza","doi":"10.1557/OPL.2016.76","DOIUrl":"https://doi.org/10.1557/OPL.2016.76","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"288 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76902073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Jaramillo, J. Posada-Correa, E. Pabón-Gelves, E. Ramos-Ramírez, N. Gutiérrez-Ortega
{"title":"Thermal and mechanical properties of nanocomposites based on polyethylene and Mg/Al hydrotalcite","authors":"L. Jaramillo, J. Posada-Correa, E. Pabón-Gelves, E. Ramos-Ramírez, N. Gutiérrez-Ortega","doi":"10.1557/OPL.2016.48","DOIUrl":"https://doi.org/10.1557/OPL.2016.48","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"98 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72588054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amorphous silicon (α-Si) was deposited on glass substrates by PECVD at different deposition conditions in order to characterize the residual stress on the film. Subsequently, a thermal-annealing was applied for different times at 400 °C in a N 2 atmosphere, aiming to reduce the stress in the films. The deposition power was between 15 and 30 W at 13.56 MHz, the pressure in the chamber was adjusted in a range from 600 to 900 mTorr, and the temperature was varied from 140 to 200 °C. The stress was determined by using the Stoney equation, measuring the curvature and thickness of the α-Si films with a stylus profilometer. A deposition rate between 7-24 nm/min was obtained, and the time for thermal-annealing needed to reduce the stress was reduced from 10 to 2-4 h, obtaining a minimum compressive stress of 17 MPa. With this value of stress, it was possible to use the α-Si as masking material for wet etching of glass during the manufacturing of microfluidic devices, in order to obtain microstructures in the glass with 150 μm in depth.
{"title":"Stress Reduction of Amorphous Silicon Deposited by PECVD","authors":"César Pérez, C. Reyes-Betanzo","doi":"10.1557/OPL.2016.26","DOIUrl":"https://doi.org/10.1557/OPL.2016.26","url":null,"abstract":"Amorphous silicon (α-Si) was deposited on glass substrates by PECVD at different deposition conditions in order to characterize the residual stress on the film. Subsequently, a thermal-annealing was applied for different times at 400 °C in a N 2 atmosphere, aiming to reduce the stress in the films. The deposition power was between 15 and 30 W at 13.56 MHz, the pressure in the chamber was adjusted in a range from 600 to 900 mTorr, and the temperature was varied from 140 to 200 °C. The stress was determined by using the Stoney equation, measuring the curvature and thickness of the α-Si films with a stylus profilometer. A deposition rate between 7-24 nm/min was obtained, and the time for thermal-annealing needed to reduce the stress was reduced from 10 to 2-4 h, obtaining a minimum compressive stress of 17 MPa. With this value of stress, it was possible to use the α-Si as masking material for wet etching of glass during the manufacturing of microfluidic devices, in order to obtain microstructures in the glass with 150 μm in depth.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"15 1","pages":"109-116"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74108069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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