scholarly journals Elastic modulus and yield strength of semicrystalline polymers with bond disorder are higher than in atomic crystals

2018 ◽  
Vol 118 ◽  
pp. 40-46 ◽  
Author(s):  
A. Giuntoli ◽  
D. Leporini
Keyword(s):  
Elastic Modulus ◽  
Yield Strength ◽  
Semicrystalline Polymers

scholarly journals Densification of Ceramic Matrix Composite Preforms by Si2N2O Formed by Reaction of Si with SiO2 under High Nitrogen Pressure. Part 2: Materials Properties

2021 ◽  
Vol 5 (7) ◽  
pp. 179
Author(s):  
Brice Taillet ◽  
René Pailler ◽  
Francis Teyssandier
Keyword(s):  
Elastic Modulus ◽  
Yield Strength ◽  
Room Temperature ◽  
Outer Part ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Nitrogen Pressure ◽  
High Nitrogen ◽  
Yield Strain ◽  
High Nitrogen Pressure

Ceramic matrix composites (CMCs) have been prepared and optimized as already described in part I of this paper. The fibrous preform made of Hi-Nicalon S fibers was densified by a matrix composed of Si2N2O prepared inside the CMC by reacting a mixture of Si and SiO2 under high nitrogen pressure. This part describes the oxidation resistance and mechanical properties of the optimized CMC. The CMC submitted to oxidation in wet oxygen at 1400 °C for 170 h exhibited an oxidation gradient from the surface to almost the center of the sample. In the outer part of the sample, Si2N2O, Si3N4 and SiC were oxidized into silica in the cristobalite-crystallized form. The matrix microstructure looks similar to the original one at the center of the sample, while at the surface large pores are observed and the fiber/matrix interphase is consumed by oxidation. The elastic modulus and the hardness measured at room temperature by nano-indentation are, respectively, 100 and 8 GPa. The elastic modulus measured at room temperature by tensile tests ranges from 150 to 160 GPa and the ultimate yield strength from 320 to 390 MPa, which corresponds to a yield strain of about 0.6%. The yield strength identified by acoustic emission is about 40 MPa.

Fatigue Behavior of Cement Asphalt Emulsion Mortar

2016 ◽  
Vol 847 ◽  
pp. 25-30 ◽  
Author(s):  
Dong Mei Tian ◽  
Jian Yin
Keyword(s):  
Elastic Modulus ◽  
Yield Strength ◽  
High Speed ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Permanent Deformation ◽  
Negative Temperature ◽  
Fatigue Tests ◽  
Asphalt Emulsion ◽  
Slab Track

As one of the key components of non-ballast slab track in high speed railway, cement asphalt emulsion mortar (CAM) has low compressive strength and low elastic modulus. This makes CAM possible to be served as supporting, height-adjusting, vibration-dissipating and deformation-fitting sandwich-layer between pre-stress slab and concrete roadbed. To study the fatigue behavior of the CAM, fatigue tests were conducted at room temperature and negative temperature, respectively. The permanent strain, elastic modulus and yield strength of fatigue-tested specimens were compared to the reference one. The results showed that the small permanent deformation lead to very little displacement differences among the slab track system. Secondly, the elastic modulus and yield strength of fatigue test specimens were both higher than that of reference one. Because the fatigue process might strengthen the CAM by compacting micro-cracks. Additionally, arising from the temperature sensitivity of asphalt, viscosity behavior of asphalt mortar at room temperature is changed to brittleness behavior at negative temperature.

The Mechanical Properties of Combustion-Sprayed Polymers and Blends

1996 ◽  
Author(s):  
J.A. Brogan ◽  
C.C. Berndt ◽  
A. Claudon ◽  
C. Coddet
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Deposition Temperature ◽  
Processing Parameters ◽  
Low Energy ◽  
Melt Compounding ◽  
Acid Copolymer ◽  
Spray Processing ◽  
Break Water

Abstract The mechanical properties of EMAA copolymer are dependent upon the thermal spray processing parameters. The parameters determine coating temperatures which, in turn, affects the microstructure. If the deposition temperature is too low, (104 °C for PFl 13 and 160 °C for PFl 11) coatings have low strengths and low energy to break values. Increased coating temperatures allow the particles to fully coalesce resulting in maximized strength and elongation to break. However, at 271 °C, PFl 11 had visible porosity which decreased both strength and elastic modulus. Pigment acts as reinforcement in the sense that the modulus increased but the elongation to break decreased, thus reducing the energy to break. Water quenching reduces the elastic modulus and yield strength, but increases the elongation to break for both EMAA formulations. The mechanical properties of post consumer commingled plastic and PCCP / EMMA blends improved if the recycled plastic was pre-processed by melt-compounding. Melt compounding increased the strength and toughness by improving the compatibility among the various polymer constituents. The addition of PCCP increases the modulus and yield strength of ethylene methaciylic acid copolymer.

scholarly journals Improving Mechanical, Thermal and Damping Properties of NiTi (Nitinol) Reinforced Aluminum Nanocomposites

2020 ◽  
Vol 4 (1) ◽  
pp. 19 ◽  
Author(s):  
Penchal Reddy Matli ◽  
Vyasaraj Manakari ◽  
Gururaj Parande ◽  
Manohar Reddy Mattli ◽  
Rana Abdul Shakoor ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Thermal Expansion ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Coefficient Of Thermal Expansion ◽  
Microwave Sintering ◽  
Hot Extrusion ◽  
Damping Capacity ◽  
Damping Properties ◽  
Niti Particle

In the present study, Ni50Ti50 (NiTi) particle reinforced aluminum nanocomposites were fabricated using microwave sintering and subsequently hot extrusion. The effect of NiTi (0, 0.5, 1.0, and 1.5 vol %) content on the microstructural, mechanical, thermal, and damping properties of the extruded Al-NiTi nanocomposites was studied. Compared to the unreinforced aluminum, hardness, ultimate compression/tensile strength and yield strength increased by 105%, 46%, 45%, and 41% while elongation and coefficient of thermal expansion (CTE) decreased by 49% and 22%, respectively. The fabricated Al-1.5 NiTi nanocomposite exhibited significantly higher damping capacity (3.23 × 10−4) and elastic modulus (78.48 ± 0.008 GPa) when compared to pure Al.

Ageing Effect on Mechanical Properties of Machined Nanostructures

2013 ◽  
Vol 683 ◽  
pp. 145-149
Author(s):  
Xing Lei Hu ◽  
Ya Zhou Sun ◽  
Ying Chun Liang ◽  
Jia Xuan Chen
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Md Simulation ◽  
Fracture Strain ◽  
Machining Process ◽  
Ageing Process ◽  
Yield Strain ◽  
Before And After ◽  
Mc Simulation

Monte Carlo (MC) method and molecular dynamics (MD) are combined to analyze the influence of ageing on mechanical properties of machined nanostructures. Single crystal copper workpiece is first cut in MD simulation, and then the machined workpiece is used in MC simulation of ageing process, finally the tensile mechanical properties of machined nanostructures before and after ageing are investigated by MD simulation. The results show that machining process and ageing have obvious influence of tensile mechanical properties. After machining, the yield strength, yield strain, fracture strain and elastic modulus reduce by 36.02%, 28.86%, 20.79% and 7.16% respectively. However, the yield strength, yield strain and elastic modulus increase by 4.84%, 1.41% and 1.02% respectively, fracture strain reduce by 24.53% after ageing process. To research the ageing processes of machined nanostructures by MC simulation is both practical and meaningful.

A Study on the Effect of the Temperature on Mechanical Properties of H90 Copper Strip

2019 ◽  
Vol 950 ◽  
pp. 65-69
Author(s):  
Sun Fei ◽  
Xu Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Effect Of Temperature ◽  
Basic Material ◽  
Copper Strip ◽  
Study Results ◽  
Different Temperatures ◽  
Strip Test

In order to study the effect of temperature on the mechanical properties of H90 copper strip material, the H90 copper strip test pieces were heated to different temperatures (20~600 °C) for tensile test; the yield strength, tensile strength, elastic modulus and elongation of H90 copper strip at different temperatures were obtained. Based on the test results, the empirical models of yield strength, tensile strength, elastic modulus of H90 copper strip at high temperature were established; the test showed that, with the increase of temperature, the yield strength, tensile strength and elastic modulus of H90 copper strip decreased greatly, and the elongation after fracture first increased-decreased-increased at 20~600 °C. The study results in this paper provide basic material data for analyzing the effect of temperature on the continuous firing of firearms and other weapons.

scholarly journals Open Porous α + β Titanium Alloy by Liquid Metal Dealloying for Biomedical Applications

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1450 ◽  
Author(s):  
Stefan Alexander Berger ◽  
Ilya Vladimirovich Okulov
Keyword(s):  
Titanium Alloy ◽  
Elastic Modulus ◽  
Liquid Metal ◽  
Yield Strength ◽  
Biomedical Applications ◽  
High Yield ◽  
High Yield Strength ◽  
Open Porous Structure ◽  
Micrometer Scale ◽  
High Deformability

Open porous dendrite-reinforced TiMo alloy was synthesized by liquid metal dealloying of the precursor Ti47.5Mo2.5Cu50 (at.%) alloy in liquid magnesium (Mg). The porous TiMo alloy consists of α-titanium and β-titanium phases and possesses a complex microstructure. The microstructure consists of micrometer scale β-titanium dendrites surrounded by submicrometer scale α-titanium ligaments. Due to the dendrite-reinforced microstructure, the porous TiMo alloy possesses relatively high yield strength value of up to 180 MPa combined with high deformability probed under compression loading. At the same time, the elastic modulus of the porous TiMo alloy (below 10 GPa) is in the range of that found for human bone. This mechanical behavior along with the open porous structure is attractive for biomedical applications and suggests opportunities for using the porous TiMo alloy in implant applications.

Design and Preparation of an Electrospun Biomaterial Surgical Patch

2009 ◽  
Vol 24 (1_suppl) ◽  
pp. 158-168 ◽  
Author(s):  
Hai Lu ◽  
Wei-Jun Chen ◽  
Yan Xing ◽  
Da-Jun Ying ◽  
Bo Jiang
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Collagen Type ◽  
Sem Images ◽  
Significant Potential ◽  
Clinical Transplantation ◽  
Porcine Pericardium ◽  
Porous Morphology

A biomaterial patch of electrospun collagen type fibers was designed and produced by electrospinning seven different concentrations (8%-20% w/v) of collagen solutions. The tensile strength, yield strength, and elastic modulus of the electrospun collagen fibrous patches were found to be suitable for clinical transplantation. No significant differences versus fresh porcine pericardium as controls were observed. The SEM images of the groups showed that the patches were smooth with uniform interwoven and porous morphology. The fibrous patches were biocompatible and did not elicit local or systemic toxic effects when implanted in vivo. These electrospun collagen fibrous patches have significant potential as surgical biomaterial patches.

Nanomechanics of rhenium wires: Elastic modulus, yield strength and strain hardening

2009 ◽  
Vol 57 (14) ◽  
pp. 4032-4035 ◽  
Author(s):  
L. Philippe ◽  
Z. Wang ◽  
I. Peyrot ◽  
A.W. Hassel ◽  
J. Michler
Keyword(s):  
Elastic Modulus ◽  
Yield Strength ◽  
Strain Hardening
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