scholarly journals Systematic investigation of the mechanical properties of pure silica zeolites: stiffness, anisotropy, and negative linear compressibility

2013 ◽  
Vol 15 (38) ◽  
pp. 16012 ◽  
Author(s):  
François-Xavier Coudert
Keyword(s):  
Mechanical Properties ◽  
Systematic Investigation ◽  
Pure Silica ◽  
Stiffness Anisotropy ◽  
Linear Compressibility

scholarly journals Effect of Cold Drawing on Mechanical Properties of Biodegradable Fibers

2017 ◽  
Vol 15 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Francesco Paolo La Mantia ◽  
Manuela Ceraulo ◽  
Maria Chiara Mistretta ◽  
Marco Morreale
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Biodegradable Polymers ◽  
Biodegradable Polymer ◽  
Cold Drawing ◽  
Thermal Characterization ◽  
Systematic Investigation ◽  
Thermomechanical Properties ◽  
Polymer Systems ◽  
The Impact

Purpose Biodegradable polymers are currently gaining importance in several fields, because they allow mitigation of the impact on the environment related to disposal of traditional, nonbiodegradable polymers, as well as reducing the utilization of oil-based sources (when they also come from renewable resources). Fibers made of biodegradable polymers are of particular interest, though, it is not easy to obtain polymer fibers with suitable mechanical properties and to tailor these to the specific application. The main ways to tailor the mechanical properties of a given biodegradable polymer fiber are based on crystallinity and orientation control. However, crystallinity can only marginally be modified during processing, while orientation can be controlled, either during hot drawing or cold stretching. In this paper, a systematic investigation of the influence of cold stretching on the mechanical and thermomechanical properties of fibers prepared from different biodegradable polymer systems was carried out. Methods Rheological and thermal characterization helped in interpreting the orientation mechanisms, also on the basis of the molecular structure of the polymer systems. Results and conclusions It was found that cold drawing strongly improved the elastic modulus, tensile strength and thermomechanical resistance of the fibers, in comparison with hot-spun fibers. The elastic modulus showed higher increment rates in the biodegradable systems upon increasing the draw ratio.

Mechanically Enhanced Precipitation of Phase-Inversion Sprayed Polyurethane Scaffold May Be Used to Match Tissue Specific Anisotropy

2009 ◽  
Author(s):  
James P. Kennedy ◽  
Robert W. Hitchcock
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Cell Culture ◽  
Pore Size ◽  
Phase Inversion ◽  
Anisotropy Ratio ◽  
Material Anisotropy ◽  
Polyurethane Scaffold ◽  
Stiffness Anisotropy

Methods of creating a scaffold for tissue engineering that allow for modification of properties such as pore size, porosity, and anisotropy are essential for tissue engineering applications. For example the pore size and material anisotropy have been shown to affect cardiomyocyte elongation and alignment [1]. Phase-inversion spray polymerization (PISP) is a method for rapidly precipitating polymers onto a surface by depositing the polymer solution simultaneously with a nonsolvent, and may be used to create biocompatible scaffolds of engineered morphological and mechanical properties by varying the solubility of the polymer in the nonsolvent [2]. We report here on the fabrication of scaffolds using different nonsolvents and methods of in-process elongation that allow for control of stiffness, anisotropy ratio, porosity, and in vitro cell culture.

Multifunctional Ti-Si-B-C-N Tribological Nanocomposite Coatings for Aerospace Applications

2007 ◽  
Vol 539-543 ◽  
pp. 173-180 ◽  
Author(s):  
In Wook Park ◽  
Brajendra Mishra ◽  
Kwang Ho Kim ◽  
John J. Moore
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
High Hardness ◽  
Systematic Investigation ◽  
304 Stainless Steel ◽  
High Fracture Toughness ◽  
Nanocomposite Coatings ◽  
High Fracture ◽  
X Ray ◽  
Wear Rates

Ti–B–C–N and Ti–Si–B–C–N nanocomposite coatings were deposited on AISI 304 stainless steel substrates by DC unbalanced magnetron sputtering from two (80mol% TiB2–20mol% TiC and 40mol% TiB2–60mol% TiC) composite targets in various Si target powers. The relationship among microstructures, mechanical properties, and tribologiacal properties was investigated. The synthesized Ti–B–C–N and Ti–Si–B–C–N coatings were characterized using x–ray diffraction (XRD) and x–ray photoelectron spectroscopy (XPS). These analyses revealed that the Ti–Si–B–C–N coatings are nanocomposites consisting of solid-solution (Ti,C,N)B2 and Ti(C,N) crystallites distributed in an amorphous TiSi2, SiC, and SiB4 matrix including some carbon, BN, CNx, TiO2, and B2O3 components. The addition of Si to the Ti–B–C–N coating led to percolation of amorphous TiSi2, SiC, and SiB4 phases. The Ti–Si–B–C–N coatings exhibited high hardness and H/E values, indicating high fracture toughness, of approximately 35 GPa and 0.098, respectively. Furthermore, the Ti–Si–B–C–N coatings exhibited very low wear rates ranging from ~3×10-7 to ~16×10-7 mm3/(N·m). The minimum friction coefficient of the Ti–Si–B–C–N coatings was approximately 0.15 at low Si target power between 25W and 50W. A systematic investigation on the microstructures, mechanical properties, and tribological properties of Ti–Si–B–C–N coatings prepared from two TiB2–TiC composite targets and one Si target is reported in this paper.

Synthesis and properties of polyimides derived from bis(4-aminophenyl)isohexides

2016 ◽  
Vol 29 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Xiaodong Ji ◽  
Jingling Yan ◽  
Xiuju Liu ◽  
Zikun Wang ◽  
Zhen Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Glass Transition ◽  
Physical And Mechanical Properties ◽  
Amic Acid ◽  
Systematic Investigation ◽  
Structure Property ◽  
Free Standing ◽  
Structure Property Relationship ◽  
Relationship Of

Several partially bio-based polyimides have been successfully synthesized by polycondensation between bis(4-aminophenyl)isohexides with various commercial dianhydrides. Flexible and free-standing films were readily obtained from their poly(amic acid) or polyimide solutions. A systematic investigation of the structure–property relationship of polyimides highlights the significant impact of the isohexides moieties on their physical and mechanical properties (glass transition temperature, inherent viscosity, thermal stability, solubility, and mechanical properties). The results revealed that these polyimides exhibited comparable thermal stability and mechanical properties to those of petrochemical-based ones.

scholarly journals Systematic exploration of the mechanical properties of 13 621 inorganic compounds

2019 ◽  
Vol 10 (37) ◽  
pp. 8589-8599 ◽  
Author(s):  
Siwar Chibani ◽  
François-Xavier Coudert
Keyword(s):  
Mechanical Properties ◽  
Elastic Properties ◽  
Inorganic Compounds ◽  
Systematic Exploration ◽  
Linear Compressibility

Exploring elastic properties of 13 621 crystals highlights how rare auxeticity and negative linear compressibility are.

Effect of Extrusion Parameters on Mechanical Properties of Al6061-Ni-P Coated SiC Composites

2013 ◽  
Author(s):  
Ramesh Chinnakurli Suryanarayana ◽  
Sikhakolli Ramakrishna ◽  
Ummar Khan Attaullah ◽  
Smitha Hanumantha Badnur ◽  
Kumar Saheb
Keyword(s):  
Mechanical Properties ◽  
Load Transfer ◽  
Hot Extrusion ◽  
Matrix Alloy ◽  
Extrusion Process ◽  
Systematic Investigation ◽  
Strength Properties ◽  
Industrial Applications ◽  
The Matrix ◽  
Sic Composites

Extrusion of metal matrix composites (MMCs) is a very challenging one where in the bond between the reinforcement and the matrix alloy is crucial in getting high quality extrusions for industrial applications. In recent years researchers are focusing on developing aluminium based composites with metallic coated reinforcement to achieve good interfacial bonds to ensure smooth load transfer from the matrix on to reinforcement. However no information is available as regards hot extrusion of metallic coated reinforced MMCs. In the light of the above, the present work focuses on a systematic investigation on effect of extrusion process parameters on mechanical properties of Al6061-Ni-P coated SiC composites. From the investigation, it is observed that hardness, yield and ultimate strength of Al2014-SiC (Both uncoated and Ni-P coated) composites are higher when compared with the matrix alloy for all the extrusion ratios studied (4:1,5:1,10:1,15.5:1) at a given extrusion temperature. However, the ductility of composites decreases with increase in extrusion ratios. Further, heat treatment has a significant effect on the studied mechanical properties. Increase in extrusion temperatures at a given extrusion ratio has resulted in decrease in hardness and strength properties of both matrix alloy and developed composites.

scholarly journals Systematic Exploration of the Mechanical Properties of 13,324 Inorganic Compounds

2019 ◽  
Author(s):  
Siwar Chibani ◽  
François-Xavier Coudert
Keyword(s):  
Mechanical Properties ◽  
Elastic Properties ◽  
Large Scale ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Inorganic Compounds ◽  
Crystalline Materials ◽  
Systematic Exploration ◽  
Feature Negative ◽  
Linear Compressibility

In order to better understand the mechanical properties of crystalline materials, we performed a large-scale exploration of the elastic properties of 13,324 crystals from the Materials Project database, including both experimentally synthesized and hypothetical structures. We studied both their average (isotropic) behavior, as well as the anisotropy of the elastic properties: bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and linear compressibility. We show that general mechanical trends, which hold for isotropic (noncrystalline) materials at the macroscopic scale, also apply “on average” for crystals. Further, we highlight the importance of elastic anisotropy and the role of mechanical stability as playing key roles in the experimental feasibility of hypothetical compounds. We also quantify the frequency of occurrence of rare anomalous mechanical properties: 3% of the crystals feature negative linear compressibility, and only 0.3% have complete auxeticity.

scholarly journals Metal–organic frameworks: the pressure is on

2015 ◽  
Vol 71 (6) ◽  
pp. 585-586 ◽  
Author(s):  
François-Xavier Coudert
Keyword(s):  
Mechanical Properties ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
Structural Transitions ◽  
Framework Materials ◽  
Metal Organic ◽  
Industrial Level ◽  
High Mechanical Stability ◽  
Linear Compressibility

Metal–organic frameworks (MOFs) demonstrate a wide variety of behavior in their response to pressure, including anomalous mechanical properties, negative linear compressibility, pressure-induced crystal-to-crystal and crystal-to-amorphous structural transitions. The discovery of framework materials combining novel pressure responses and high mechanical stability is key in the quest for applications of MOFs at the industrial level.

Investigation of the transport, structural and mechanical properties of half-metallic REMnO3 (RE = Ce and Pr) ferromagnets

RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 97641-97649 ◽  
Author(s):  
Shakeel Ahmad Khandy ◽  
Dinesh C. Gupta
Keyword(s):  
Mechanical Properties ◽  
Ground State ◽  
First Principles ◽  
Perovskite Oxides ◽  
Systematic Investigation ◽  
Ground State Structure ◽  
First Principles Calculations ◽  
State Structure ◽  
Half Metallicity ◽  
Half Metallic

Systematic investigation of the ground state structure, elastic and transport properties, of perovskite oxides REMnO3 (RE = Ce and Pr) has been carried out by first principles calculations. The half-metallicity and ferromagnetism is well explained.

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