材料物理与化学进展(英文)最新文献

{"title":"Bi-Modal Failure Mechanism of Rolling Contact Bearings","authors":"Y. Meged","doi":"10.4236/ampc.2020.1010017","DOIUrl":"https://doi.org/10.4236/ampc.2020.1010017","url":null,"abstract":"The theory of failure of rolling contact bearings is based on fluctuating high level loading and material fatigue. This theory is unimodal, considering only the solid components of the bearing, and ignoring the liquid phase, which is the lubricant. Bearing life is rather dispersed, reaching a ratio of 20 between the extreme values. Since this theory was established, several exceptional phenomena were detected that could not be explained by it, such as: 1) Pitting damage beyond the contact path; 2) Detrimental effect of a minute quantity of water in the lubricant on bearing life. 25 ppm of water in the lubricant brought about shorter bearing life by over than 30%. The bimodal failure theory considers both solid and liquid bearing components. The damaging process of the lubricant evolves from its cavitation. During this process vapor filled cavities are formed in low pressure zones. When these cavities reach high pressure zones they implode exothermally. These implosions cause local high pressure pulses reaching 30,000 at accompanied by a temperature rise of about 2000 degrees K [1]. This paper includes cavitation erosion test results on stainless steel samples by vibratory and water tunnel test rigs. Various methods of lubricant dehydration are presented and evaluated. The main conclusion from this analysis is the use of water-free lubricants, for long life of RC bearings and more uniform service life thereof.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48016890","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":"Real and Fitted Spherical Indentations","authors":"G. Kaupp","doi":"10.4236/ampc.2020.1010016","DOIUrl":"https://doi.org/10.4236/ampc.2020.1010016","url":null,"abstract":"Spherical indentations that rely on original date are analyzed with the physically correct mathematical formula and its integration that take into account the radius over depth changes upon penetration. Linear plots, phase-transition onsets, energies, and pressures are algebraically obtained for germanium, zinc-oxide and gallium-nitride. There are low pressure phase-transitions that correspond to, or are not resolved by hydrostatic anvil onset pressures. This enables the attribution of polymorph structures, by comparing with known structures from pulsed laser deposition or molecular beam epitaxy and twinning. The spherical indentation is the easiest way for the synthesis and further characterization of polymorphs, now available in pure form under diamond calotte and in contact with their corresponding less dense polymorph. The unprecedented results and new possibilities require loading curves from experimental data. These are now easily distinguished from data that are “fitted” to make them concur with widely used unphysical Johnson’s formula for spheres (“P = (4/3)h3/2R1/2E∗”) not taking care of the R/h variation. Its challenge is indispensable, because its use involves “fitting equations” for making the data concur. These faked reports (no “experimental” data) provide dangerous false moduli and theories. The fitted spherical indentation reports with radii ranging from 4 to 250 μm are identified for PDMS, GaAs, Al, Si, SiC, MgO, and Steel. The detailed analysis reveals characteristic features.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46715032","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":"Structural Characterization of Thin Epitaxial GaN Films on Polymer Polyimides Substrates by Ion Beam Assisted Deposition","authors":"S. Vidawati, J. Gerlach, Benjamin Herold, B. Rauschenbach","doi":"10.4236/AMPC.2020.109015","DOIUrl":"https://doi.org/10.4236/AMPC.2020.109015","url":null,"abstract":"The Epitaxial GaN thin films have been fabricated by Ion Beam Assisted Deposition (IBAD) process using nitrogen ions with hyperthermal energies on the polyimides polymer substrates. By applying with the Reflection of High-Energy Electron Diffraction (RHEED), Scanning Electron Microscopy (SEM) and Quantum Design Physical Properties Measurement System, the behaviour of hexagonal GaN thin films is investigated. The result showed that the high quality of the deposited GaN layers kept appearing for many parameters depending on the temperature greatly. The behaviour of high quality of epitaxial GaN coating on the polyimide polymer substrates is a promising material for optoelectronic devices and semiconductor devices application.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44744817","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":"Characteristics of a Type of NTC Thermistors for Cryogenic Applications","authors":"Yuqi Lan, Shenyin Yang, G. B. Chen, Sifeng Yang","doi":"10.4236/ampc.2020.108012","DOIUrl":"https://doi.org/10.4236/ampc.2020.108012","url":null,"abstract":"A new type of miniature negative temperature coefficient (NTC) thermistors has been developed and manufactured with Mn-Ni-Cu-Fe oxides. The prepared NTC thermistors were calibrated in the temperature range from 77 K to 300 K with 1 μA exciting currents. The automatic calibration apparatus as well as thermometric characteristics, stability, calibration equations and interchangeability of the manufactured thermistors were investigated. A mean fit equation was obtained: 1/T = 8.60 × 10−4 + 6.54 × 10−4 ln(R/Rref) + 2.46 × 10−5 ln(R/Rref)2 + 9.48 × 10−7 ln(R/Rref)3 − 2.16 × 10−8 ln(R/Rref)4. All the prepared NTC thermistors agreed with this fit with an error of 1.5 K. If the greater accuracy is required, a calibration is necessary, and the calibration accuracy is estimated to be ±10 mK.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45526178","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":"Influence of the Annealing Temperature on the Thickness and Roughness of La2Ti2O7 Thin Films","authors":"M. Baba, Ala Gasim, A. Awadelgied, N. Almuslet, A. Salih","doi":"10.4236/ampc.2020.108014","DOIUrl":"https://doi.org/10.4236/ampc.2020.108014","url":null,"abstract":"In this work, the impact of the substrate annealing temperature on the thickness and roughness of La2Ti2O7 thin films was verified. A group of LTO Thin films was grown on Si (100) substrates successfully via pulsed laser deposition technique (PLD) at various annealing temperatures with a constant numbers of pulses and energy per pulse. Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) were used to investigate the thickness and roughness of the deposited La2Ti2O7 thin films. The average thickness of the thin films was decreased due to the increasing in the annealing temperature linearly; the maximum thickness was found (231 nm) when LTO thin film deposited at 500°C. The root mean square roughness was increased linearly with increasing the substrate Temperatures. The minimum roughness was found (0.254 nm) when LTO deposited at (500°C). From the obtained results, its clear evidence that the annealing temperature has an influence on the thickness and roughness of the LTO thin films.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42899788","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":"The Formula of Dependence of Mechanical Characteristics of Materials on Crystalline Phase Composition in the Matrix","authors":"Z. Kovziridze","doi":"10.4236/ampc.2020.108013","DOIUrl":"https://doi.org/10.4236/ampc.2020.108013","url":null,"abstract":"Objective: For materials science and generally, for long-term operation of work-pieces in industry the significant role is attributed to dependence of macro-mechanical properties of consolidated body on crystalline phase composition, its dimensions, form, distribution in matrix and the form factor. While working in responsible fields of technology of ceramics and ceramic composites the above referred properties are attributed extremely great role with the view of durability and endurance at the terms of heavy mechanical loads. For description of the resistance of any concrete type work-piece, the crystalline phase plays the greatest role in mechanical strength or deformation of any material. It plays the important role in correlative explanation of materials mechanics and matrix properties. In our case, in the process of destruction of ceramic materials and composites, which will give us exhaustive response to the role of macro- and micro-mechanical properties of materials, the role of a macro- and micro-structural component, that is, of crystalline phase in the process of transition of stable state of materials into meta-stable state is extremely big. Our study aims to develop a formula of dependence of macro-mechanical properties of ceramic and ceramic composites on crystalline phase, the most powerful component of their structure, which will enable theorists and practitioners to select and develop technologies and technological processes correctly. Method: On the basis of the study of micro- and macro-mechanical properties of ceramics and ceramic composites and the morphology of crystalline phase and the analysis of the study we determined and created parameters of the formula. Results: The formula covers macro-mechanical properties, that is when the work-piece is thoroughly destructed: mechanic at bending at three and four-point load, mechanic at contraction; among morphological characteristics: composition of crystalline phase and their spreading in matrix, their sizes, form factor; correlative dependence of the above listed properties. Absolutely new definition of a factor of spreading of crystalline phase in matrix is offered. Conclusion: The created formula is of consolidated nature and it can be used in technology of any ceramic material and ceramic composites. The formula will help practitioners to plan correctly and fulfill accurately all positions of technology of production of work-pieces, to carry out the most responsible thermal treatment process of technology of manufacture of work-pieces; to determine correlation between mechanical and matrix properties of materials.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":"10 1","pages":"178-188"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41905988","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":"Required CIGS and CIGS/Mo Interface Properties for High-Efficiency Cu(In, Ga)Se2 Based Solar Cells","authors":"S. Ouédraogo, M. B. Kebre, A. Ngoupo, Daouda Oubda, F. Zougmore, J. Ndjaka","doi":"10.4236/ampc.2020.107011","DOIUrl":"https://doi.org/10.4236/ampc.2020.107011","url":null,"abstract":"In this work, we have modeled and simulated the electrical performance of CIGS thin-film solar cell using one-dimensional simulation software (SCAPS-1D). Starting from a baseline model that reproduced the experimental results, the properties of the absorber layer and the CIGS/Mo interface have been explored, and the requirements for high-efficiency CIGS solar cell were proposed. Simulation results show that the band-gap, acceptor density, defect density are crucial parameters that affect the performance of the solar cell. The best conversion efficiency is obtained when the absorber band-gap is around 1.2 eV, the acceptor density at 1016 cm−3 and the defect density less than 1014 cm−3. In addition, CIGS/Mo interface has been investigated. It appears that a thin MoSe2 layer reduces recombination at this interface. An improvement of 1.5 to 2.5 mA/cm2 in the current density (Jsc) depending on the absorber thickness is obtained.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48052959","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":"Structure, Plastic Deformation of Polyethylene: A Molecular Dynamics Method","authors":"D. Trong, T. Quoc, H. Minh, Cuong Nguyen Chinh, Van Duong Quoc","doi":"10.4236/ampc.2020.106010","DOIUrl":"https://doi.org/10.4236/ampc.2020.106010","url":null,"abstract":"This paper studies the influence factors of atoms number (N) at temperature (T) and after annealing time (t) on the structure shape and the plastic deformation of Polyethylene C2H4 (PE) by the Molecular Dynamics (MD) method with Dreading pair interaction, cyclic boundary conditions and plastic deformation of Polyethylene (PE) be done by stretching method according to the z-axis. The results of structure, plastic deformation of PE are analyzed through size (l), the total energy of the system (Etot), shape and associated energy (Ebond), angular binding energy (Eangle), energy Edihedral, interactive energy Vander Walls (Enon-bonding). When increasing N, t leads to the number of structural units of Face-Centred Cubic (FCC), Body-Centered Cubic (BCC) and Hexagonal Close-Packed (HCP) increasing, but Amorphous (Amor) decreases while the angle between the atoms is a constant corresponding to 109.5°. Besides, the length of the link (r) increases from r = 1.529 A to r = 1.558 A while the plastic deformation energy of PE gets an enormous change and the bonding angle at 109.27°. The length of the link r = 1.529 A and the size (l) of the PE material increase from l = 3.73 nm to l = 6.63 nm while the total energy of system (Etotal) decreases from Etotal = −1586 eV to Etotal = −7891 eV with the transition temperature is T = 103 K. Increasing the number of atoms leads to increasing the length of the link. The total energy Etotal of the system decreases, but the number of structural units in FCC, HCP, BCC and Amor increase, which leads to the length of the link increases, the Etotal decreases, and there is a change in the plastic deformation characteristics of PE. In contrast, increasing T leads to the plastic deformation increases, and PE moves from the amorphous state to the liquid state. The obtained results are very significant for future experimental research.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":"10 1","pages":"125-150"},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41664945","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":"Tissue Matrices Scaffold for the Preparation of Lithium Cobalt Oxide","authors":"P. Ahamed, Mohammad Abu Yousuf","doi":"10.4236/ampc.2020.105009","DOIUrl":"https://doi.org/10.4236/ampc.2020.105009","url":null,"abstract":"This study reports an innovative approach of solid state reaction for the production of lithium cobalt oxide (LiCoO2/LCO) using commercially available tissue matrices. Li+ and Co2+ grafted tissue matrices calcined at 700°C for 6 hours to prepare black color LCO materials. A series of techniques such as FT-IR, XRD, FESEM, TGA and UV-visible spectroscopy were applied for characterization of the prepared LCO materials. Fourier-transform infrared spectroscopy (FT-IR) data identified the vibration mode of CoO6 and O-Co-O in the prepared LCO materials. FESEM images of tissue assisted LCO possessed larger size and voids compared to the LCO prepared without any tissue matrix. X-ray diffraction (XRD) data approved the layer structure of LCO with R3m space group. Analysis of XRD spectra revealed that tissue matrices reduced the unit cell lattice constant of LCO materials. Properties such as X-ray density (ρx), bulk density (ρb) and grain size (D) have been calculated from the XRD spectrum for assessment of the structural properties of the prepared LCO materials. Thermal analysis results indicated the relation of tissue matrix combustion carbon coating on LCO surface for different absorption behavior of the prepared materials. The band gap of tissue assisted LCO was found to decrease compared to the LCO prepared without tissue matrix. The synthesis method used in this study can be broadly applicable as a simple and inexpensive approach for the preparation of LCO materials of Li-ion battery.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46623174","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":"The Extent of Solubilization of Flurbiprofen and Ketoprofen by Cetyltrimethylammonium Micelles Using Semi-Equilibrium Dialysis","authors":"Jimmy D Roach, Ibrahim Laswi, Malik Mushannen, Ali Chaari, Mandy M. Bondaruk","doi":"10.4236/ampc.2020.104008","DOIUrl":"https://doi.org/10.4236/ampc.2020.104008","url":null,"abstract":"The partitioning of two non-steroidal \u0000anti-inflammatory drugs (NSAIDs), flurbiprofen and ketoprofen, into cationic \u0000cetyltrimethylammonium micelles was investigated using semi-equilibrium \u0000dialysis at 37℃ in phosphate buffered saline. The micellar-water \u0000solubilization equilibrium constants for both NSAIDs, in their deprotonated \u0000forms, were observed to decrease linearly with increasing mole fraction of drug \u0000in micelles. For flurbiprofen, the solubilization constant in the limit as mole \u0000fraction of drug in micelles approaches zero was found to be 11,200 (co = 1 M), while for ketoprofen the value was 1950 (co = 1 M). Using 1H-NMR and UV spectroscopic techniques, the locus of solubilization \u0000for ketoprofen was found to be towards the charged exterior of the micelles, in \u0000the Stern layer, whereas flurbiprofen was found to solubilize more in the \u0000micellar interior.","PeriodicalId":68199,"journal":{"name":"材料物理与化学进展(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41779077","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}