Pub Date : 2018-02-05DOI: 10.4172/2169-0022.1000423
D. Khlaifia, T. Mestiri, L. Mabrouk, K. Alimi
Benzo[1,2-b:5-B’]dithiophene (BDT)–based small molecules with acceptor-donor-acceptor (A-D-A) structure were designed based on the experimental system BDTT-S-TR (1) for use as potential donor materials for organic photovoltaic (OPV) devices. Their geometry structures, electronic properties and other key parameters related to OPVs such as absorption spectra, energetic driving forces ΔE L-L, power conversion efficiencies (PCEs) and intramolecular charge transfer properties have been investigated by means of density functional theory (DFT) and time dependent density functional theory (TDDFT) methods. These have been exploited as donor materials for a heterojunction with [6,6] phenyl-C71-butyric acid methyl ester (PC70BM) as acceptor material. Based on Marks model, an excellent agreement between the experimental and predicted PCE was obtained for the reported system 1/PC70BM and a significant improvement in PCEs of BHJ devices based on 2-4/PC70BM was manifested. The charge transfer rates of the interfacial charge transfer Kint er−CT and recombination Kint er −CR in 1-4/PC70BM heterojunctions have been calculated using Marcus-Levich-Jortner rate equation. The calculations show that the ratios Kint er-CT / kint er-CR for the 2-4/PC70BM heterojunctions are ~104 times higher than that of the 1/PC70BM. From these predictions, we reached our purpose to provide rational design of three novel molecules that will be more promising candidates for high-efficiency SMs OPVs materials.
{"title":"Theoretical Approach Towards Rational Design and Characterization of Benzo[1,2-b:5-B’]dithiophene (BDT)-Based (A-D-A) Small Molecules of Relevance for High Performance Solar Cells","authors":"D. Khlaifia, T. Mestiri, L. Mabrouk, K. Alimi","doi":"10.4172/2169-0022.1000423","DOIUrl":"https://doi.org/10.4172/2169-0022.1000423","url":null,"abstract":"Benzo[1,2-b:5-B’]dithiophene (BDT)–based small molecules with acceptor-donor-acceptor (A-D-A) structure were designed based on the experimental system BDTT-S-TR (1) for use as potential donor materials for organic photovoltaic (OPV) devices. Their geometry structures, electronic properties and other key parameters related to OPVs such as absorption spectra, energetic driving forces ΔE L-L, power conversion efficiencies (PCEs) and intramolecular charge transfer properties have been investigated by means of density functional theory (DFT) and time dependent density functional theory (TDDFT) methods. These have been exploited as donor materials for a heterojunction with [6,6] phenyl-C71-butyric acid methyl ester (PC70BM) as acceptor material. Based on Marks model, an excellent agreement between the experimental and predicted PCE was obtained for the reported system 1/PC70BM and a significant improvement in PCEs of BHJ devices based on 2-4/PC70BM was manifested. The charge transfer rates of the interfacial charge transfer Kint er−CT and recombination Kint er −CR in 1-4/PC70BM heterojunctions have been calculated using Marcus-Levich-Jortner rate equation. The calculations show that the ratios Kint er-CT / kint er-CR for the 2-4/PC70BM heterojunctions are ~104 times higher than that of the 1/PC70BM. From these predictions, we reached our purpose to provide rational design of three novel molecules that will be more promising candidates for high-efficiency SMs OPVs materials.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"22 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2018-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85717994","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}
Pub Date : 2018-02-05DOI: 10.4172/2169-0022.1000418
Ali Radhi, Iacobellis, K. Beahdinan
Crystalline characterization poses a challenge when atomic deformation and phase transformation are occurring in an atomic simulation. Surface features are also of great importance to discern bulk features from surface properties and surface science. Embedded atomic features are conventionally characterized by high value parameters to distinguish them from perfect crystalline phase to extract crack tips, dislocations, surfaces and other crystalline features. Common neighborhood analysis has been presented as an adjusted method to characterize those features with enhanced formulation to the current framework to characterize non-monoatomic interactions. The present work introduces a novel approach to characterize crystalline structures by means of cumulative common neighborhood parameterization (CCNP) for arbitrary structures. The method is compared with centrosymmetry parameter CSP and common neighborhood parameter CNA. The results showed a better performance in discerning surface and bulk features with a high visible range between bulk, surface and other atoms. The method was also extended to characterize a complex P42/mnm space group, non-monoatomic crystal with no common first nearest neighbors.
{"title":"A Cumulative Approach to Common Neighborhood Analysis for Crystalline Structure Characterization in Atomistic Simulations","authors":"Ali Radhi, Iacobellis, K. Beahdinan","doi":"10.4172/2169-0022.1000418","DOIUrl":"https://doi.org/10.4172/2169-0022.1000418","url":null,"abstract":"Crystalline characterization poses a challenge when atomic deformation and phase transformation are occurring in an atomic simulation. Surface features are also of great importance to discern bulk features from surface properties and surface science. Embedded atomic features are conventionally characterized by high value parameters to distinguish them from perfect crystalline phase to extract crack tips, dislocations, surfaces and other crystalline features. Common neighborhood analysis has been presented as an adjusted method to characterize those features with enhanced formulation to the current framework to characterize non-monoatomic interactions. The present work introduces a novel approach to characterize crystalline structures by means of cumulative common neighborhood parameterization (CCNP) for arbitrary structures. The method is compared with centrosymmetry parameter CSP and common neighborhood parameter CNA. The results showed a better performance in discerning surface and bulk features with a high visible range between bulk, surface and other atoms. The method was also extended to characterize a complex P42/mnm space group, non-monoatomic crystal with no common first nearest neighbors.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"37 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2018-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88603446","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}
Pub Date : 2018-01-28DOI: 10.4172/2169-0022.1000416
E. Elbadry, G. Abdalla, M. Aboraia, E. Oraby
The objective of this work is to compare the mechanical properties including tensile, bending and impact properties between different glass fiber architecture reinforced polyester composites which are fabricated by a hand lay-up technique. The effects of stacking sequences of glass fibers consists of five layers which mainly are plain woven, short fiber, and sandwich layer glass composites on the mechanical properties of composites have been studied. The results showed that the tensile and bending properties of all different composite laminates are significantly higher compared to the neat resin. The plain woven glass reinforced polyester composites showed the highest values compared with other composite laminates. As the glass fiber mats a core are tightly packed and absorbs the impact stresses and distributes them evenly in the composites sandwich layer, the glass composites showed the highest value of impact strength compared with other composite laminates. Moreover, from SEM investigations, in these composites, there is an inverse relationship between the amount of delamination and the amount of hackles, and as the hackles increase the mechanical properties including tensile and bending of these composites are enhanced.
{"title":"Effect of Glass Fibers Stacking Sequence on the Mechanical Properties of Glass Fiber/Polyester Composites","authors":"E. Elbadry, G. Abdalla, M. Aboraia, E. Oraby","doi":"10.4172/2169-0022.1000416","DOIUrl":"https://doi.org/10.4172/2169-0022.1000416","url":null,"abstract":"The objective of this work is to compare the mechanical properties including tensile, bending and impact properties between different glass fiber architecture reinforced polyester composites which are fabricated by a hand lay-up technique. The effects of stacking sequences of glass fibers consists of five layers which mainly are plain woven, short fiber, and sandwich layer glass composites on the mechanical properties of composites have been studied. The results showed that the tensile and bending properties of all different composite laminates are significantly higher compared to the neat resin. The plain woven glass reinforced polyester composites showed the highest values compared with other composite laminates. As the glass fiber mats a core are tightly packed and absorbs the impact stresses and distributes them evenly in the composites sandwich layer, the glass composites showed the highest value of impact strength compared with other composite laminates. Moreover, from SEM investigations, in these composites, there is an inverse relationship between the amount of delamination and the amount of hackles, and as the hackles increase the mechanical properties including tensile and bending of these composites are enhanced.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"214 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75576269","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}
Pub Date : 2018-01-03DOI: 10.4172/2169-0022.1000414
R. Dhivya, J. Ranjani, J. Rajendhran, J. Mayandi, J. Annaraj
The curcumin loaded PMMA-AA/ZnO nanocomposite potentially inhibited the growth of AGS cancer tumour in male Swiss albino mouse, which showed a promising targeted cancer therapy. Interestingly the given bio-nanocomposite was rapidly cleared from the organs with negligible exhibition of toxicity. From the obtained results it is understood that the apoptosis has been occurred through mitochondrial disruption-mediated pathway. Also these nanomaterials could efficiently hinder the Go/G1 transition along with cycle progression at S-phase transition due to the radiation-induced DNA damage. These findings declared that the auspicious candidate, curcumin could be successfully delivered into the target by the polymer encapsulated ZnO NPs and exhibited a potent activity against gastric cancer cells at molecular and cellular levels as well as cell proliferation in a panel of tumour cells
{"title":"pH Triggered Curcumin Release from PMMA-AA Coated ZnO Nanoparticles for Excellent Anti-Gastric Cancer Therapy","authors":"R. Dhivya, J. Ranjani, J. Rajendhran, J. Mayandi, J. Annaraj","doi":"10.4172/2169-0022.1000414","DOIUrl":"https://doi.org/10.4172/2169-0022.1000414","url":null,"abstract":"The curcumin loaded PMMA-AA/ZnO nanocomposite potentially inhibited the growth of AGS cancer tumour in male Swiss albino mouse, which showed a promising targeted cancer therapy. Interestingly the given bio-nanocomposite was rapidly cleared from the organs with negligible exhibition of toxicity. From the obtained results it is understood that the apoptosis has been occurred through mitochondrial disruption-mediated pathway. Also these nanomaterials could efficiently hinder the Go/G1 transition along with cycle progression at S-phase transition due to the radiation-induced DNA damage. These findings declared that the auspicious candidate, curcumin could be successfully delivered into the target by the polymer encapsulated ZnO NPs and exhibited a potent activity against gastric cancer cells at molecular and cellular levels as well as cell proliferation in a panel of tumour cells","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"27 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80095620","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}
Pub Date : 2018-01-03DOI: 10.4172/2169-0022.1000413
S. Saranya, S. Muthuselvi, M. PremaRani
Hydroxyapatite (HAp) having chemical formula Ca10 (PO4)6(OH)2 is the main chemical component of human bone tissue (70%), to cope up with the bone response as a bio active material. In this study Ni doped HAp powder with triclinic phase was synthesized by sol-gel method, by doping Ni of different concentrations (0.02, 0.04, 0.06, and 0.08). The various properties due to different concentration of Ni in HAp were characterized by X-ray diffraction analysis (XRD), Energy dispersive x-ray spectroscopy (EDX) and Fourier transform spectroscopy (FT-IR). The thermal gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HAP powder. Antibacterial activity of compounds against microbial pathogens was done using well diffusion method. High antibacterial activity was observed for Ca0.98 Ni0.02 (PO4)(OH)2. The transmission electron microscopic analysis confirms the presence of the spherical shape morphology of the prepared hydroxyapatite nanoparticle with the particle size of around 20 to 100 nm.
{"title":"Structural, Optical and Antimicrobial Analysis of Nickel Doped HAp Synthesized by Solgel Method for Biomedical Applications","authors":"S. Saranya, S. Muthuselvi, M. PremaRani","doi":"10.4172/2169-0022.1000413","DOIUrl":"https://doi.org/10.4172/2169-0022.1000413","url":null,"abstract":"Hydroxyapatite (HAp) having chemical formula Ca10 (PO4)6(OH)2 is the main chemical component of human bone tissue (70%), to cope up with the bone response as a bio active material. In this study Ni doped HAp powder with triclinic phase was synthesized by sol-gel method, by doping Ni of different concentrations (0.02, 0.04, 0.06, and 0.08). The various properties due to different concentration of Ni in HAp were characterized by X-ray diffraction analysis (XRD), Energy dispersive x-ray spectroscopy (EDX) and Fourier transform spectroscopy (FT-IR). The thermal gravimetric analysis (TGA-DTA) was also carried out to evaluate the stability of the synthesized HAP powder. Antibacterial activity of compounds against microbial pathogens was done using well diffusion method. High antibacterial activity was observed for Ca0.98 Ni0.02 (PO4)(OH)2. The transmission electron microscopic analysis confirms the presence of the spherical shape morphology of the prepared hydroxyapatite nanoparticle with the particle size of around 20 to 100 nm.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"73 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86967040","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}
Pub Date : 2018-01-03DOI: 10.4172/2169-0022.1000411
Growene W Queirós, L. GarcíaSánchez, G. D. S. Jm, Criado Portal Aj
Boron steels are very interesting as wear resistant materials. In this research we propose a boron steel without alloys, 30MnB5, with a new thermal treatment that exceeds the mechanical characteristics of conventional treatment. The 30MnB5 steel, with the new sub-critical annealing and water quenching heat treatment, also exceeds the RAEX450. The new treatment has important advantages, such as: energy savings and reduction of costs and manufacturing times. It also has a more favourable ACV than 30MnB5 with conventional heat treatment and RAEX450. Its wear resistance is significantly improved compared to the classic heat-treated 30MnB5 and the RAEX450.
{"title":"Improved Wear Resistance of Boron Steels by Subcritical Annealing and Hardening with Production Cost Savings and Lower Environmental Impact","authors":"Growene W Queirós, L. GarcíaSánchez, G. D. S. Jm, Criado Portal Aj","doi":"10.4172/2169-0022.1000411","DOIUrl":"https://doi.org/10.4172/2169-0022.1000411","url":null,"abstract":"Boron steels are very interesting as wear resistant materials. In this research we propose a boron steel without alloys, 30MnB5, with a new thermal treatment that exceeds the mechanical characteristics of conventional treatment. The 30MnB5 steel, with the new sub-critical annealing and water quenching heat treatment, also exceeds the RAEX450. The new treatment has important advantages, such as: energy savings and reduction of costs and manufacturing times. It also has a more favourable ACV than 30MnB5 with conventional heat treatment and RAEX450. Its wear resistance is significantly improved compared to the classic heat-treated 30MnB5 and the RAEX450.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"8 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75692663","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}
Pub Date : 2018-01-01DOI: 10.4172/2169-0022.1000424
S. Uran
Relatively new optical techniques are utilized to study the oxidation of low-index crystal faces of a zirconium doped single crystal β-NiAl. With these non-destructive techniques residual stress, phase composition and thickness of the scales were determined at various temperatures. The results are compared with the results obtained from an undoped counterpart. Interesting differences in scale stress, thickness and phase composition have been observed. The residual stress evolves rather differently than that on the undoped counterpart. Initial lower stress levels in the doped crystal convert to higher stresses at higher oxidation temperatures. The orientation dependence and a stress anomaly observed with the undoped single crystal β-NiAl are still present on the doped sample. Fluorescence and Raman results indicate a higher concentration of θ-Al2O3 on all crystallographic phases with Zr doping. The oxide scales are also thinner on the Zr doped specimen.
{"title":"Effect of Zirconium Doping on Oxidation of Single Crystal β-NiAl","authors":"S. Uran","doi":"10.4172/2169-0022.1000424","DOIUrl":"https://doi.org/10.4172/2169-0022.1000424","url":null,"abstract":"Relatively new optical techniques are utilized to study the oxidation of low-index crystal faces of a zirconium doped single crystal β-NiAl. With these non-destructive techniques residual stress, phase composition and thickness of the scales were determined at various temperatures. The results are compared with the results obtained from an undoped counterpart. Interesting differences in scale stress, thickness and phase composition have been observed. The residual stress evolves rather differently than that on the undoped counterpart. Initial lower stress levels in the doped crystal convert to higher stresses at higher oxidation temperatures. The orientation dependence and a stress anomaly observed with the undoped single crystal β-NiAl are still present on the doped sample. Fluorescence and Raman results indicate a higher concentration of θ-Al2O3 on all crystallographic phases with Zr doping. The oxide scales are also thinner on the Zr doped specimen.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"43 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75513203","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}
Pub Date : 2018-01-01DOI: 10.4172/2169-0022.1000502
V. Simonov, K. Bakhrunov
The paper shows that the presence of aluminium oxide is conditioned by the residual air content in the chamber, which deteriorates the coating quality. In this connection, the residual pressure and content of aluminium oxide were calculated in the chamber of the circulation setup.
{"title":"Thermodynamical Calculation of Residual Air Pressure in the Working Chamber of a Circulation Setup","authors":"V. Simonov, K. Bakhrunov","doi":"10.4172/2169-0022.1000502","DOIUrl":"https://doi.org/10.4172/2169-0022.1000502","url":null,"abstract":"The paper shows that the presence of aluminium oxide is conditioned by the residual air content in the chamber, which deteriorates the coating quality. In this connection, the residual pressure and content of aluminium oxide were calculated in the chamber of the circulation setup.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"26 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78247021","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}
Pub Date : 2018-01-01DOI: 10.4172/2169-0022.1000456
D. Balakrishnan, M. Gérard, D. D. Frari, S. Girod, W. Olthuis, César Pascual-García
The electrochemical control of molecular concentrations in liquids is quite challenging because of the small ratio of interacting sites between the electrode surface and the number of molecules in the volume. Here we review our recent works aiming the control of proton concentration combining redox self-assembled monolayers with a modified platform. We used Aminothiolphenol, to obtain coatings with quasi-reversible redox states able to exchange protons with the electrolyte at low voltages using different polymerization methods. We studied their charge exchange during different cycles, which would provide us the possibility to use different cycles of reactions controlled by acidity. We achieved the control of proton concentration over the liquid with an efficient design of the microfluidic device to control the diffusion of protons avoiding the reduction of hydrogen at the counter electrode and providing long lasting stability to carry control of chemical reactions during several tenths of minutes. The experiments were carried out in aqueous environment using a pH fluorescence marker to track the pH that allowed us to monitor the proton concentration down to pH 5, where the fluorescence molecule lost its sensitivity, while calculations indicate that the pH can be below 1.
{"title":"Redox Active Polymer as a pH Actuator on a Re-Sealable Microfluidic Platform","authors":"D. Balakrishnan, M. Gérard, D. D. Frari, S. Girod, W. Olthuis, César Pascual-García","doi":"10.4172/2169-0022.1000456","DOIUrl":"https://doi.org/10.4172/2169-0022.1000456","url":null,"abstract":"The electrochemical control of molecular concentrations in liquids is quite challenging because of the small ratio of interacting sites between the electrode surface and the number of molecules in the volume. Here we review our recent works aiming the control of proton concentration combining redox self-assembled monolayers with a modified platform. We used Aminothiolphenol, to obtain coatings with quasi-reversible redox states able to exchange protons with the electrolyte at low voltages using different polymerization methods. We studied their charge exchange during different cycles, which would provide us the possibility to use different cycles of reactions controlled by acidity. We achieved the control of proton concentration over the liquid with an efficient design of the microfluidic device to control the diffusion of protons avoiding the reduction of hydrogen at the counter electrode and providing long lasting stability to carry control of chemical reactions during several tenths of minutes. The experiments were carried out in aqueous environment using a pH fluorescence marker to track the pH that allowed us to monitor the proton concentration down to pH 5, where the fluorescence molecule lost its sensitivity, while calculations indicate that the pH can be below 1.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"321 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76104645","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}
Pub Date : 2018-01-01DOI: 10.4172/2169-0022.1000473
G. Kaupp
A sodium chloride single crystal is depth-sensing indented with a Vickers indenter at a Zwick/Roell ZHV Zwicky Z2.5 macro region instrument, together with Stephanie Rosner from Zwick GmbH & Co KG, Ulm, Germany. Normal forces up to 50 N load and 120 μm depth are applied, to experimentally secure the onsets of known and to locate new phase-changes with direct linear regression analyses, avoiding iterations. The author's physically deduced universal eqns. (1-7) are used for the data analyses. Four sharp phase-change onsets could thus be experimentally located, revealing four new polymorphs of NaCl in addition to the long known fcc and bcc polymorphs. Their relation to the three theoretically predicted higher pressure crystal structures in Reference is thus not clear. The predicted metallic character is unclear: no color formation or metallic reflection was observed by the author up to 50 N loads. No cracking of any type occurs at the indenter tip, but a new type of long-range cracking at the 30 N ranges occurred, and its highly resolved microscopy reveal two-step nucleation from a polymorphs’ interface exit. Inverted 3D microscopy of the residual impressions of the author with his Keyence VHX 100 microscope reveals crystallization of halite cubes upon unloading. The physical hardness increases (factor 5.9), the physical indentation modulus decreases (factor 2.3) upon load. The indentation phase-transformation energies cover 7 powers of 10. These data question the reliability of non-depth-sensing ISO/ASTM Standards of industrial Vickers, Brinell, and Rockwell, etc hardness parameters, as they cannot consider inevitable multiple phase-changes at very high loads, do not characterize the pristine rather than phase-transformed industrial material (including super-alloys), and miss the permissible pressure stress for avoiding phase changes. The risk of failure by nucleation of cracks at polymorph interfaces requires depth-sensing. Deviations from the mathematically required 5/4 ratio of applied-work over indentation-work are a rapid means to reveal phasechanges from old published loading curves by their graphical integration.
{"title":"Six Polymorphs of Sodium Chloride upon Depth-Sensing Macroindentation with Unusual Long-Range Cracks Requiring 30 N Load","authors":"G. Kaupp","doi":"10.4172/2169-0022.1000473","DOIUrl":"https://doi.org/10.4172/2169-0022.1000473","url":null,"abstract":"A sodium chloride single crystal is depth-sensing indented with a Vickers indenter at a Zwick/Roell ZHV Zwicky Z2.5 macro region instrument, together with Stephanie Rosner from Zwick GmbH & Co KG, Ulm, Germany. Normal forces up to 50 N load and 120 μm depth are applied, to experimentally secure the onsets of known and to locate new phase-changes with direct linear regression analyses, avoiding iterations. The author's physically deduced universal eqns. (1-7) are used for the data analyses. Four sharp phase-change onsets could thus be experimentally located, revealing four new polymorphs of NaCl in addition to the long known fcc and bcc polymorphs. Their relation to the three theoretically predicted higher pressure crystal structures in Reference is thus not clear. The predicted metallic character is unclear: no color formation or metallic reflection was observed by the author up to 50 N loads. No cracking of any type occurs at the indenter tip, but a new type of long-range cracking at the 30 N ranges occurred, and its highly resolved microscopy reveal two-step nucleation from a polymorphs’ interface exit. Inverted 3D microscopy of the residual impressions of the author with his Keyence VHX 100 microscope reveals crystallization of halite cubes upon unloading. The physical hardness increases (factor 5.9), the physical indentation modulus decreases (factor 2.3) upon load. The indentation phase-transformation energies cover 7 powers of 10. These data question the reliability of non-depth-sensing ISO/ASTM Standards of industrial Vickers, Brinell, and Rockwell, etc hardness parameters, as they cannot consider inevitable multiple phase-changes at very high loads, do not characterize the pristine rather than phase-transformed industrial material (including super-alloys), and miss the permissible pressure stress for avoiding phase changes. The risk of failure by nucleation of cracks at polymorph interfaces requires depth-sensing. Deviations from the mathematically required 5/4 ratio of applied-work over indentation-work are a rapid means to reveal phasechanges from old published loading curves by their graphical integration.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"281 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75205729","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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