Highly refractory composites with predominant volume fraction of TiB 2 , were “in situ” synthesized and consolidated. The production process was carried out using elemental powders by means of self-propagating high-temperature synthesis under pseudo-hot isostatic pressure (SHS-pseudo-HIP). The Ti:B atomic ratio corresponded to TiB 2 formation, and Cr:C atomic ratio has been established in (3:2) molar ratio. Based on scanning electron images (SEI), very high relative density was obtained with nearly full densification in composite with intended 85vol.% of TiB 2 , which is sufficiently high concentration of boron from the perspective of neutron shielding. However XRD results indicated formation of CrB and TiC, next to TiB 2 . This clearly indicates no equilibrium in pseudo-binary TiB 2 -Cr 3 C 2 system. Besides, broadened peaks in XRD patterns as well as gradient of composition in EDS maps may indicate solid solutions, especially (Ti,Cr)C. The existence of (Ti,Cr) solid solutions and ternary compounds is possible, considering Hume-Rothery rules for hypothetical mutual solubility.
{"title":"In situ SHS-pseudo-HIP as an effective method to develop neutron shielding ceramic matrix composites from quaternary Ti-B-Cr-C system","authors":"Marta Ziemnicka-Sylwester, P. Litwa, T. Czujko","doi":"10.1557/OPL.2016.66","DOIUrl":"https://doi.org/10.1557/OPL.2016.66","url":null,"abstract":"Highly refractory composites with predominant volume fraction of TiB 2 , were “in situ” synthesized and consolidated. The production process was carried out using elemental powders by means of self-propagating high-temperature synthesis under pseudo-hot isostatic pressure (SHS-pseudo-HIP). The Ti:B atomic ratio corresponded to TiB 2 formation, and Cr:C atomic ratio has been established in (3:2) molar ratio. Based on scanning electron images (SEI), very high relative density was obtained with nearly full densification in composite with intended 85vol.% of TiB 2 , which is sufficiently high concentration of boron from the perspective of neutron shielding. However XRD results indicated formation of CrB and TiC, next to TiB 2 . This clearly indicates no equilibrium in pseudo-binary TiB 2 -Cr 3 C 2 system. Besides, broadened peaks in XRD patterns as well as gradient of composition in EDS maps may indicate solid solutions, especially (Ti,Cr)C. The existence of (Ti,Cr) solid solutions and ternary compounds is possible, considering Hume-Rothery rules for hypothetical mutual solubility.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76292557","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":"Optimization of the Atmospheric Plasma Spray Parameters using Design of Experiments for Coatings on AISI 410 Stainless Steel","authors":"E. Perez, C. E. Cruz, J. López, J. Toscano","doi":"10.1557/OPL.2016.18","DOIUrl":"https://doi.org/10.1557/OPL.2016.18","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"33 1","pages":"53-64"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73498476","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}
C. Rodríguez-Rivera, J. García-Hinojosa, F. Rodríguez-Gómez
{"title":"Effect of the Fe/Cu Relationship Corrosion and low Alloying Elements on Corrosion Behavior of Cast Aluminum Parts","authors":"C. Rodríguez-Rivera, J. García-Hinojosa, F. Rodríguez-Gómez","doi":"10.1557/OPL.2016.89","DOIUrl":"https://doi.org/10.1557/OPL.2016.89","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85977591","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. Bahrami, M. Pech-Canul, C. A. Gutiérrez, N. Soltani
The quantitative effect of the following parameters on the one single step pressureless infiltration characteristics of bilayer B 4 C p /rice-husk ash (RHA) porous preforms by aluminum alloys was investigated using the Taguchi method and analysis of variance (ANOVA): infiltration temperature and time, B 4 C particle size, RHA percentage, percentage porosity in the preforms, and magnesium content in the alloy. The contributions of each of the parameters to the retained porosity, hardness and modulus of elasticity of the resulting bilayer composites were determined. The parameters that most significantly impact the modulus of elasticity ( E ) of the resulting composites are chemical composition of Al alloy followed by porosity of preforms and B 4 C particle size. Their relative contributions to the variance in the values of modulus of elasticity are 25.7, 22.48 and 18.44 %, respectively. Verification tests conducted using the established optimum parameters show a good agreement with those of projected values.
采用田口法(Taguchi)和方差分析(ANOVA)研究了以下参数对双层b4c p /稻壳灰(RHA)多孔预制件铝合金单步无压入渗特性的定量影响:入渗温度和时间、b4c粒径、RHA百分比、预制件孔隙率和合金镁含量。测定了各参数对双层复合材料的孔隙率、硬度和弹性模量的影响。对复合材料弹性模量(E)影响最大的参数是铝合金的化学成分，其次是预成形件的孔隙率和b4c的粒度。它们对弹性模量值方差的相对贡献分别为25.7%、22.48%和18.44%。利用所建立的最优参数进行的验证试验表明，该参数与预测值吻合良好。
{"title":"Microstructure and properties of bilayer-graded Al-matrix composites by one-step pressureless infiltration of B 4 C/rice-husk ash preforms","authors":"A. Bahrami, M. Pech-Canul, C. A. Gutiérrez, N. Soltani","doi":"10.1557/OPL.2016.68","DOIUrl":"https://doi.org/10.1557/OPL.2016.68","url":null,"abstract":"The quantitative effect of the following parameters on the one single step pressureless infiltration characteristics of bilayer B 4 C p /rice-husk ash (RHA) porous preforms by aluminum alloys was investigated using the Taguchi method and analysis of variance (ANOVA): infiltration temperature and time, B 4 C particle size, RHA percentage, percentage porosity in the preforms, and magnesium content in the alloy. The contributions of each of the parameters to the retained porosity, hardness and modulus of elasticity of the resulting bilayer composites were determined. The parameters that most significantly impact the modulus of elasticity ( E ) of the resulting composites are chemical composition of Al alloy followed by porosity of preforms and B 4 C particle size. Their relative contributions to the variance in the values of modulus of elasticity are 25.7, 22.48 and 18.44 %, respectively. Verification tests conducted using the established optimum parameters show a good agreement with those of projected values.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88472137","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}
O. F. Cortés-Salmerón, M. L. García-Chávez, T. García-Mejía
{"title":"Effect of Sodium Silicate Properties in Alkali-Activation of Mexican Blast Furnace Slag","authors":"O. F. Cortés-Salmerón, M. L. García-Chávez, T. García-Mejía","doi":"10.1557/OPL.2016.4","DOIUrl":"https://doi.org/10.1557/OPL.2016.4","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88698641","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}
O. Pluchery, L. Caillard, A. Rynder, F. Rochet, Yingjie Zhang, M. Salmeron, Y. Chabal
Gold nanoparticles can be used as ultimate electrical materials for storing electrons or controlling their flow for the next generation nano-electronic devices. These particles are the core element of assemblies where the electrical current is reduced to the smallest possible since electrons are controlled one by one by using the Coulomb blockade phenomenon. We prepared colloidal gold nanoparticles beteween 4 and 15 nm and grafted them on a grafted organic monolayer (GOM) on silicon. GOM are highly ordered monolayers prepared by hydrosilylation of alkene molecules and subsequently modified with an amine group so that gold nanoparticles can be firmly immobilized on top of the layer. We discuss several electrical properties at a single electron level. Using the conductive tip of KPFM, we were also able to reveal the spontaneous charging behavior of the gold nanoparticles so that the local work function of a 10 nm gold nanoparticle is only 3.7 eV. By placing an STM tip above a nanoparticle, Coulomb blockade allows controlling the number of electrons simultaneously injected in the nanoparticle. This opens the way for new kinds of single electron memories or single electron transistors.
{"title":"Single charge electronics with gold nanoparticles and organic monolayers","authors":"O. Pluchery, L. Caillard, A. Rynder, F. Rochet, Yingjie Zhang, M. Salmeron, Y. Chabal","doi":"10.1557/OPL.2016.40","DOIUrl":"https://doi.org/10.1557/OPL.2016.40","url":null,"abstract":"Gold nanoparticles can be used as ultimate electrical materials for storing electrons or controlling their flow for the next generation nano-electronic devices. These particles are the core element of assemblies where the electrical current is reduced to the smallest possible since electrons are controlled one by one by using the Coulomb blockade phenomenon. We prepared colloidal gold nanoparticles beteween 4 and 15 nm and grafted them on a grafted organic monolayer (GOM) on silicon. GOM are highly ordered monolayers prepared by hydrosilylation of alkene molecules and subsequently modified with an amine group so that gold nanoparticles can be firmly immobilized on top of the layer. We discuss several electrical properties at a single electron level. Using the conductive tip of KPFM, we were also able to reveal the spontaneous charging behavior of the gold nanoparticles so that the local work function of a 10 nm gold nanoparticle is only 3.7 eV. By placing an STM tip above a nanoparticle, Coulomb blockade allows controlling the number of electrons simultaneously injected in the nanoparticle. This opens the way for new kinds of single electron memories or single electron transistors.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"76 1","pages":"60-72"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90999554","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}
G. Altamirano-Guerrero, E. Gutiérrez-Castañeda, O. García-Rincón, A. Salinas-Rodríguez
This article outlines the use of quenching dilatometry in phase transformation kinetics research in steels under continuous cooling conditions. For this purpose, the phase transformation behavior of a hot-rolled heat treatable steel was investigated over the cooling rate range of 0.1 to 200 °C/s. The start and finish points of the austenite transformation were identified from the dilatometric curves and then the continuous cooling transformation (CCT) diagrams were constructed. The experimental CCT diagrams were verified by microstructural characterization using scanning electron microscopy (SEM) and Vickers micro-hardness. In general, results revealed that the quenching dilatometry technique is a powerful tool for the characterization and study of solid-solid phase transformations in steels. For cooling rates between 200 and 25 °C/s the final microstructure consists on plate-like martensite with the highest hardness values. By contrast, a mixture of phases of ferrite, bainite and pearlite predominated for slower cooling rates (10-0.1 °C/s).
{"title":"Experimental Determination of Continuous Cooling Transformation Diagrams of Hot-Rolled Heat Treatable Steel Plates Using Quenching Dilatometry","authors":"G. Altamirano-Guerrero, E. Gutiérrez-Castañeda, O. García-Rincón, A. Salinas-Rodríguez","doi":"10.1557/OPL.2016.29","DOIUrl":"https://doi.org/10.1557/OPL.2016.29","url":null,"abstract":"This article outlines the use of quenching dilatometry in phase transformation kinetics research in steels under continuous cooling conditions. For this purpose, the phase transformation behavior of a hot-rolled heat treatable steel was investigated over the cooling rate range of 0.1 to 200 °C/s. The start and finish points of the austenite transformation were identified from the dilatometric curves and then the continuous cooling transformation (CCT) diagrams were constructed. The experimental CCT diagrams were verified by microstructural characterization using scanning electron microscopy (SEM) and Vickers micro-hardness. In general, results revealed that the quenching dilatometry technique is a powerful tool for the characterization and study of solid-solid phase transformations in steels. For cooling rates between 200 and 25 °C/s the final microstructure consists on plate-like martensite with the highest hardness values. By contrast, a mixture of phases of ferrite, bainite and pearlite predominated for slower cooling rates (10-0.1 °C/s).","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"25 1","pages":"129-134"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88356415","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}
J. López-Cuevas, M. Pech-Canul, J. C. Rendón-Angeles, J. L. Rodríguez-Galicia, C. A. Gutiérrez-Chavarría
{"title":"Wollastonite - Tricalcium Phosphate Glass-Ceramics of Eutectic Composition Synthesized by the Glass-Crystallization Method","authors":"J. López-Cuevas, M. Pech-Canul, J. C. Rendón-Angeles, J. L. Rodríguez-Galicia, C. A. Gutiérrez-Chavarría","doi":"10.1557/OPL.2016.22","DOIUrl":"https://doi.org/10.1557/OPL.2016.22","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"23 1","pages":"83-88"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89466574","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}
M. Garza-Castañón, C. Vela, K. Serrano, J. Tudón-Martínez
Several experimental efforts related to the concrete improvement are focused to increase its flexural strength to complement the high compressive strength, which is usually developed by materials of this nature. The flexural strength or modulus of rupture of the concrete is important in civil engineering applications such as infrastructure projects, pavements and buildings. This work proposes an alternative to optimize concrete flexural strength through the functionalization of the 9 Angstrom (A) Tobermorite using Carbon Nanotubes (CNT). A complete ab-initio, 3D Atomistic Model of the 9A Tobermorite is presented as the basis of the silicate cementitious hydrated products. In order to validate the model, some mechanical properties were computed using a Density Functional Theory (DFT) based program. Afterwards, a functionalization based on CNTs with different diameters was carried out to improve the flexural strength of the concrete.
{"title":"CNT-based functionalization of 9A tobermorite to optimize concrete flexural strength","authors":"M. Garza-Castañón, C. Vela, K. Serrano, J. Tudón-Martínez","doi":"10.1557/OPL.2016.6","DOIUrl":"https://doi.org/10.1557/OPL.2016.6","url":null,"abstract":"Several experimental efforts related to the concrete improvement are focused to increase its flexural strength to complement the high compressive strength, which is usually developed by materials of this nature. The flexural strength or modulus of rupture of the concrete is important in civil engineering applications such as infrastructure projects, pavements and buildings. This work proposes an alternative to optimize concrete flexural strength through the functionalization of the 9 Angstrom (A) Tobermorite using Carbon Nanotubes (CNT). A complete ab-initio, 3D Atomistic Model of the 9A Tobermorite is presented as the basis of the silicate cementitious hydrated products. In order to validate the model, some mechanical properties were computed using a Density Functional Theory (DFT) based program. Afterwards, a functionalization based on CNTs with different diameters was carried out to improve the flexural strength of the concrete.","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78653769","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. A. P. Macedo, C. E. Velasquez, C. A. Silva, C. Pereira
{"title":"NEUTRONIC PERFORMANCE OF (U, Pu)C FUEL IN A LATTICE OF GFR USING SCALE 6.0","authors":"A. A. P. Macedo, C. E. Velasquez, C. A. Silva, C. Pereira","doi":"10.1557/OPL.2016.32","DOIUrl":"https://doi.org/10.1557/OPL.2016.32","url":null,"abstract":"","PeriodicalId":18884,"journal":{"name":"MRS Proceedings","volume":"91 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81989035","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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