An Experimental Study of Carbon Nanotube Reinforcements

2011 ◽  
Author(s):  
Lauren Patrin ◽  
Frank Chow ◽  
Gabriela Philippart ◽  
Feridun Delale ◽  
Benjamin Liaw ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Young's Modulus ◽  
Testing Machine ◽  
Type I ◽  
Electrical Measurements ◽  
Standard Type ◽  
Reinforcement Percentage

Due to their high strength and stiffness carbon nanotubes (CNTs) have been considered as candidates for reinforcement of polymeric resins. It is also known that the addition of CNTs to polymeric matrix results in highly conductive nanocomposites, making the material multifunctional. Most of the CNT reinforced polymeric nanocomposite systems reported in the literature have been studied at room temperature. However, in many applications, materials may be subjected from low to elevated temperatures. Thus, the aim of this research is to study CNT reinforced polypropylene (PP) specimens at room, elevated and low temperatures. ASTM standard Type I specimens manufactured via injection molding and reinforced with 0.2%, 1%, 3%, and 6% CNTs were first subjected to tensile loads in a universal testing machine at room temperature. Neat PP resin specimens were also tested to provide baseline data. The tests were repeated at −54°C (−65°F), −20°C (−4°F), 49°C (120°F) and 71°C (160°F). The results were plotted as stress-strain curves and analyzed to delineate the effect of CNT reinforcement percentage and temperature on the mechanical properties. It was noted that as the percentage of CNT reinforcement increases, the resulting nanocomposite becomes stiffer (higher Young’s modulus), has higher strength and becomes more brittle. Temperature has a drastic effect on the behavior of the nanocomposite. As the temperature increases, at a given reinforcement percentage the material becomes more ductile with significantly lower Young’s modulus and strength compared to room temperature. At lower temperatures, the nanocomposite becomes more brittle with higher stiffness and strength, but significantly reduced failure strain. Also electrical measurements were conducted on the specimens to measure their resistance. For specimens reinforced with up to 3% of CNTs no electrical conductivity was detected. As expected at 6% CNT reinforcement (which is above the approximately 4% percolation limit reported in the literature), the specimens became electrically conductive. To predict the mechanical properties obtained experimentally, a micromechanics based model is presented and compared with the experimental results.

Mechanical Properties of Carboxymethyl Cellulose-Oleic Acid Solid Biopolymer Electrolyte

2018 ◽  
Vol 929 ◽  
pp. 186-190 ◽  
Author(s):  
M.N. Chai ◽  
M.M. Chai ◽  
M.I.N. Isa
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Oleic Acid ◽  
Young’S Modulus ◽  
Carboxymethyl Cellulose ◽  
Young's Modulus ◽  
Testing Machine ◽  
Strain Curve ◽  
Weight Percentage ◽  
Universal Material Testing Machine

In this paper, the mechanical properties of carboxymethyl cellulose-oleic acid (CMC-OA) solid bio-polymer electrolyte (SBE) were examined. The host, CMC was doped with different weight percentage (wt. %) of OA in the CMC-OA solution. The SBEs were tested by using the Universal Material Testing Machine where the readings of tensile strength and Young’s modulus can be obtained from the stress-strain curve produced by the software during the tension test. The sample of CMC doped with 20% wt. of OA was found to obtain the highest value of tensile strength and Young’s modulus which is 0.2069 MPa and 4.615 MPa respectively.

Effects of Hydrogen Absorption on the Mechanical Properties of Zr-Nb Alloys

2007 ◽  
Vol 1043 ◽  
Author(s):  
Shunichiro Nishioka ◽  
Masato Ito ◽  
Hiroaki Muta ◽  
Masayoshi Uno ◽  
Shinsuke Yamanaka
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Young’S Modulus ◽  
Hydrogen Content ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Young's Modulus ◽  
Characteristic Vibration ◽  
Young’S Moduli ◽  
Vibration Technique

AbstractYoung's moduli of hydrogenated Zr-Nb alloys were evaluated by using a multiple elastometer in the temperature range from room temperature to 773 K, based on the cantilever characteristic vibration technique. The decreasing rate of Young's modulus against the temperature was independent on the additive amount of Nb. The Young's modulus for the hydrogen solid solution of Zr-Nb alloys decreased and that those for the alloys with partially precipitated hydride slightly changed with increasing hydrogen content in both of Zr-1.0Nb and Zr-2.5Nb. The decreasing rates with hydrogen content of hydrogen solid solution of Zr-Nb alloys were almost same as that of Zr hydrogen solid solution. This result was considered because all specimens largely consisted of α-zirconium in which the solute hydrogen was found to decrease the Young's modulus.

Experimental Setup for the Determination of Mechanical Solder Materials Properties at Elevated Temperatures

2010 ◽  
Vol 638-642 ◽  
pp. 3793-3798
Author(s):  
Wolfgang H. Müller ◽  
Holger Worrack ◽  
Jens Sterthaus
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Elevated Temperatures ◽  
Young's Modulus ◽  
Linear Optimization ◽  
Strain Curve ◽  
Stress And Strain ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Non Linear

The fabrication of microelectronic and micromechanical devices leads to the use of only very small amounts of matter, which can behave quite differently than the corresponding bulk. Clearly, the materials will age and it is important to gather information on the (changing) material characteristics. In particular, Young’s modulus, yield stress, and hardness are of great interest. Moreover, a complete stress-strain curve is desirable for a detailed material characterization and simulation of a component, e.g., by Finite Elements (FE). However, since the amount of matter is so small and it is the intention to describe its behavior as realistic as possible, miniature tests are used for measuring the mechanical properties. In this paper two miniature tests are presented for this purpose, a mini-uniaxial-tension-test and a nanoindenter experiment. In the tensile test the axial load is prescribed and the corresponding extension of the specimen length is recorded, both of which determines the stress-strain- curve directly. The stress-strain curves are analyzed by assuming a non-linear relationship between stress and strain of the Ramberg-Osgood type and by fitting the corresponding parameters to the experimental data (obtained for various microelectronic solders) by means of a non-linear optimization routine. For a detailed analysis of very local mechanical properties nanoindentation is used, resulting primarily in load vs. indentation-depth data. According to the procedure of Oliver and Pharr this data can be used to obtain hardness and Young’s modulus but not a complete stress-strain curve, at least not directly. In order to obtain such a stress-strain-curve, the nanoindentation experiment is combined with FE and the coefficients involved in the corresponding constitutive equations for stress and strain are obtained by means of the inverse method. The stress-strain curves from nanoindentation and tensile tests are compared for two mate-rials (aluminum and steel). Differences are explained in terms of the locality of the measurement. Finally, material properties at elevated temperature are of particular interest in order to characterize the materials even more completely. We describe the setup for hot stage nanoindentation tests in context with first results for selected materials.

scholarly journals Effect of Co-Addition of Ag and Cu on Mechanical Properties of Sn–5Sb Lead-Free Solder

2021 ◽  
Author(s):  
Biao Yuan ◽  
Zhimin Liang ◽  
Zongyuan Yang ◽  
Fei Shen ◽  
Da Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Solder Joints ◽  
Young's Modulus ◽  
Lead Free ◽  
Unloading Rate ◽  
Free Solder ◽  
Co Addition ◽  
Lead Free Solders

AbstractSn–Sb lead-free solders are considered to substitute the tin–lead solders due to their great mechanical properties. At room temperature, the mechanical properties of Ni/Au/Sn–5Sb/Au/Ni and Ni/Au/Sn–5Sb–0.3Ag–0.05Cu/Au/Ni linear solder joints were investigated by nanoindentation experiments at different loads. The results showed that the Sn–Sb intermetallic compound (IMC) was distributed in the β-Sn matrix in Ni/Au/Sn–5Sb/Au/Ni solder joints. Co-addition of Cu and Ag resulted in the formation of the rod-shaped Cu6Sn5 and the fine granular Ag3Sn IMCs. At the same load and loading/unloading rate, the indentation depth and residual indentation morphologies of Ni/Au/Sn–5Sb–0.3Ag–0.05Cu/Au/Ni solder joints were smaller than those of Ni/Au/Sn–5Sb/Au/Ni solder joints. The hardness of the two kinds of solder joints decreased with the increase in load, while the Young’s modulus was independent of load. In addition, compared to the Ni/Au/Sn–5Sb/Au/Ni solder joints, the hardness, Young’s modulus and stress exponents of Ni/Au/Sn–5Sb–0.3Ag–0.05Cu/Au/Ni solder joints achieved an improvement due to the co-addition of Ag and Cu.

Mechanical Properties of Tendons: Changes With Sterilization and Preservation

1996 ◽  
Vol 118 (1) ◽  
pp. 56-61 ◽  
Author(s):  
C. W. Smith ◽  
I. S. Young ◽  
J. N. Kearney
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Freeze Drying ◽  
Dynamic Testing ◽  
Young's Modulus ◽  
Testing Machine ◽  
Ultimate Tensile Stress ◽  
Tissue Banks ◽  
Freeze Dried ◽  
Significant Difference

Tendon allografts are commonly used to replace damaged anterior cruciate ligaments (ACL). Some of the sterilization and preservation techniques used by tissue banks with tendon allografts are thought to impair the mechanical properties of graft tissues. The tensile mechanical properties of porcine toe extensor tendons were measured using a dynamic testing machine following either freezing, freeze-drying, freezing then irradiation at 25 kGy (2.5 MRad), freeze-drying then irradiation, or freeze-drying then ethylene oxide gas sterilization. There was a small but significant difference in Young’s modulus between the frozen group (0.88 GPa ± 0.09 SD) and both the fresh group (0.98 GPa ± 0.12 SD) and the frozen irradiated group (0.97 GPa ± 0.08 SD). No values of Young’s modulus were obtained for the freeze-dried irradiated tendons. The ultimate tensile stress (UTS) of the freeze-dried irradiated group (4.7 MPa ± 4.8 SD) was significantly different from both the fresh and the frozen irradiated groups, being reduced by approximately 90 percent. There were no significant changes in UTS or Young’s modulus between any of the other groups. If irradiation is to be used to sterilize a tendon replacement for an ACL it must take place after freeze-drying to maintain mechanical properties.

Numerical modeling of the effects hydration and number of hydrogen bonds on the mechanical properties of the tropocollagen molecule

2020 ◽  
Vol 234 (3) ◽  
pp. 299-306 ◽  
Author(s):  
Marouane El Mouss ◽  
Amna Rekik ◽  
Said Zellagui ◽  
Tarek Merzouki ◽  
Ridha Hambli
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Hydrogen Bonds ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Collagen Molecule ◽  
Uniaxial Tensile ◽  
Type I ◽  
Two Parameters

Bone aging involves structural and molecular modifications, especially at the level of type I tropocollagen. This macromolecule shows two main age-related alterations, which are the decrease of both molecular diameter (due to the loss of hydration) and number of hydrogen bonds. In this work, it is proposed to investigate the influence of these two parameters (molecular diameter and number of hydrogen bonds) on the mechanical behavior of tropocollagen using finite element method. To this end, a novel three-dimensional finite element model of collagen molecule accounting for hydrogen bonds was developed. Then, a numerical design of experiments for the diameter of tropocollagen and variations in the number of hydrogen bonds has been established. The mechanical properties (“load–strain” curve and apparent Young’s modulus) of the collagen molecule were obtained by employing the proposed model to uniaxial tensile tests. The parametric study demonstrates that the mechanical properties of tropocollagen are slightly affected by the rate of hydration but considerably affected by variation of the number of hydrogen bonds. Finally, a fitted analytical function was deduced from the above results showing effects of the two parameters (hydration rate and hydrogen bonds) on the apparent Young’s modulus of tropocollagen. This study could be useful to understand the influence of structural age modifications of tropocollagen on the macroscopic mechanical properties of bone.

scholarly journals Deformation mechanisms and effect of oxygen addition on mechanical properties of Ti-7.5Mo alloy with α” martensite

2020 ◽  
Vol 321 ◽  
pp. 11059
Author(s):  
Xin Ji ◽  
Ivan Gutierrez-Urrutia ◽  
Satoshi Emura ◽  
Koichi Tsuchiya
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Oxygen Content ◽  
Tensile Deformation ◽  
Young's Modulus ◽  
Strengthening Mechanism ◽  
High Yield ◽  
Type I ◽  
Solid Solution Strengthening ◽  
Effect Of Oxygen

Effect of oxygen content as an important interstitial solute on the microstructure and mechanical properties of Ti-7.5Mo alloy was investigated. With increasing the oxygen content, the yielding strength, ultimate tensile strength and Young’s modulus of Ti-7.5Mo-xO (x=0, 0.2, 0.3, 0.4, 0.5) alloys increased, while the elongation showing a decreasing tendency. Solid-solution strengthening by the oxygen atoms has been addressed as the main strengthening mechanism. Ti-7.5Mo-xO (x ≤ 0.3) alloys have been regarded with an excellent combination of high yield strength (~640 MPa) and elongation (~28%), as well as low Young’s modulus (~60 GPa). The deformation microstructure of orthorhombic-α” martensite in Ti-7.5Mo alloy was also investigated by tracking a change in the microstructure of a selected area upon tensile deformation. Deformation twins induced by 5% tensile straining was identified as {112}α”-type I twins, which had not been reported before in α”martensite in β-Ti alloys.

Mechanical Properties of Interpenetrating Graphite/2024Al Composites Produced by Improved Squeeze Exhaust Casting

2007 ◽  
Vol 353-358 ◽  
pp. 1471-1474 ◽  
Author(s):  
Chen Su ◽  
Gao Hui Wu ◽  
Jing Qiao ◽  
Long Tao Jiang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Fracture Mechanism ◽  
Room Temperature ◽  
Squeeze Casting ◽  
Young's Modulus ◽  
Fracture Surfaces ◽  
3D Network

The graphite/2024Al composites have been fabricated by improved Squeeze Exhaust Casting (SQEC) method. Two kinds of graphite preforms with porosities of 13% and 17% respectively were infiltrated with 2024Al (Al-5Cu-2Mg) alloy under the pressure of 73MPa. The disadvantages of traditional Squeeze Casting (SQC) were avoided and the distribution of aluminum alloy appeared homogenous 3D network in the composites. Flexural strength and Young’s modulus were determined at room temperature. Compared to graphite preform, the composites exhibited a significant enhancement of mechanical properties. The flexural strength and Young’s modulus of X-Y direction of G186/2024Al composites increased from 38.6MPa to 99.7MPa and from 10.1GPa to 19.7GPa, respectively. The fracture mechanism of the composites was discussed on the basis of fracture surfaces.

Individual Phase Mechanical Properties at Different Temperatures of Sn–Ag–Cu Lead-Free Solders Incorporating Special Pileup Effects Using Nanoindentation

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Muhammad Sadiq ◽  
Jean-Sebastien Lecomte ◽  
Mohammed Cherkaoui
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Young's Modulus ◽  
Individual Phase ◽  
Different Temperatures ◽  
Coarse Microstructure ◽  
The Individual ◽  
Continuous Stiffness Measurement

Sn–Ag–Cu (SAC) alloys are considered as good replacements of Sn–Pb alloys which are banned due to the toxic nature of Pb. But, SAC alloys have a coarse microstructure that consists of β-Sn rich and eutectic phases. Nanoindentation is a useful technique to evaluate the mechanical properties at very small length scale. In this work, continuous stiffness measurement (CSM) nanoindentation setup (CSM Instruments SA, Peseux, Switzerland) is used to determine the individual phase mechanical properties like Young's modulus and hardness at high temperatures. It is demonstrated that these properties are a function of temperature for both β-Sn rich and eutectic phases. Loadings starting from 500 μN up to 5000 μN are used with 500 μN steps and average values are presented for Young's modulus and hardness. The loading rates applied are twice that of the loadings. High temperatures result in a higher creep deformation and therefore, to avoid it, different dwell times are used at peak loads. The special pileup effect, which is more significant at elevated temperatures, is determined and incorporated into the results. A better agreement is found with the previous studies.

scholarly journals Effect of Elevated Temperatures on the Mechanical Properties of a Direct Laser Deposited Ti-6Al-4V

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6432
Author(s):  
Sergei Ivanov ◽  
Marina Gushchina ◽  
Antoni Artinov ◽  
Maxim Khomutov ◽  
Evgenii Zemlyakov
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
Young’S Modulus ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Process Conditions ◽  
Relaxation Processes ◽  
Direct Laser

In the present work, the mechanical properties of the DLD-processed Ti-6Al-4V alloy were obtained by tensile tests performed at different temperatures, ranging from 20 °C to 800 °C. Thereby, the process conditions were close to the conditions used to produce large-sized structures using the DLD method, resulting in specimens having the same initial martensitic microstructure. According to the obtained stress curves, the yield strength decreases gradually by 40% when the temperature is increased to 500 °C. Similar behavior is observed for the tensile strength. However, further heating above 500 °C leads to a significant increase in the softening rate. It was found that the DLD-processed Ti-6Al-4V alloy had a Young’s modulus with higher thermal stability than conventionally processed alloys. At 500 °C, the Young’s modulus of the DLD alloy was 46% higher than that of the wrought alloy. The influence of the thermal history on the stress relaxation for the cases where 500 °C and 700 °C were the maximum temperatures was studied. It was revealed that stress relaxation processes are decisive for the formation of residual stresses at temperatures above 700 °C, which is especially important for small-sized parts produced by the DLD method. The coefficient of thermal expansion was investigated up to 1050 °C.

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