The Texture Evolutions of Mg Alloy, AZ31, under Uni-Axial Loading

2005 ◽  
Vol 495-497 ◽  
pp. 1585-1590 ◽  
Author(s):  
Sang Bong Yi ◽  
Heinz Günter Brokmeier ◽  
R. Bolmaro ◽  
Karl Ulrich Kainer ◽  
Jens Homeyer
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Loading Condition ◽  
Extrusion Direction ◽  
Axial Loading ◽  
X Rays ◽  
The Common ◽  
Initial Texture ◽  
Strain Hardening Rate

The texture influence on the mechanical behavior during uniaxial tension was studied in AZ31 (Mg – 3 Al – 1 Zn in wt.%), one of the common wrought Mg alloys. Since three tensile samples were cut in 0°, 45°, 90° to the extrusion direction, the initial bar texture influences on the mechanical behavior differently. In-situ texture measurements were carried out using hard X-rays under loading condition. According to the initial texture loading results in a variation of the mechanical behavior (yield strength, ultimate tensile strength and strain hardening rate) and in different final textures. The different texture development in each sample relates directly to the activation of different deformation systems, which is strongly influenced by the initial texture

Enhanced Mechanical-Integrity Characterization of Oilwell Annular Sealants Under In-Situ Downhole Conditions

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2308-2319
Author(s):  
Walmy Cuello Jimenez ◽  
Robert Darbe ◽  
Xueyu Pang
Keyword(s):  
Tensile Strength ◽  
Standardized Testing ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Axial Loading ◽  
Testing Apparatus ◽  
Testing Procedures ◽  
Preliminary Validation ◽  
Three Samples

Summary In this study, we describe an innovative and novel methodology comprising a high–pressure/high–temperature (HP/HT) in–situ–triaxial–testing apparatus for the measurement of sealant mechanical properties (i.e., compressive strength, Young's modulus, and tensile strength) under simulated downhole conditions. The equipment can be used to perform both curing and testing using the same apparatus, thus eliminating depressurization and cooling of test specimens. Additionally, at minimum, three samples can be tested sequentially for statistical analysis and uncertainty mitigation, along with performing real–time monitoring of total HP/HT shrinkage/expansion. The testing apparatus is rated to 30,000 psi for axial loading, 20,000 psi for confining loading, and 400°F. Preliminary validation of Young's modulus was performed with five different plastic samples, yielding error percentages of less than 5% compared to measurements performed using a standardized loading frame. Compressive– and tensile–strength validations were performed using a 16–lbm/gal cement design, and error percentages of less than 2.5 and 7%, respectively, were obtained compared to standardized testing procedures or other studies of the subject. Moreover, a 16–lbm/gal cement system was also used to help assess the functionality of the testing apparatus under simulated wellbore conditions with temperature and pressure ranging from 80 to 350°F and 3,000 to 8,000 psi, respectively.

scholarly journals Effect of In Situ Grown BNNTs and Preparation Temperature on Mechanical Behavior of SiC/SiC Minicomposites

2021 ◽  
Author(s):  
Shenwei Xu ◽  
Huilong Pi ◽  
Pengfei Wu ◽  
Yuan Shi ◽  
Haitang Yang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Fracture Strain ◽  
Thermal Structure ◽  
Annealing Process ◽  
Tangent Modulus ◽  
Tensile Fracture ◽  
Preparation Temperature

Abstract In this paper, effect of in situ grown boron nitride nanotubes (BNNTs) and preparation temperature on mechanical behavior of PIP (Precursor Infiltration and Pyrolysis) SiC/SiC minicomposites under monotonic and compliance tensile is investigated. In situ BNNTs are grown on the surface of SiC fibers using ball milling – annealing process. Composite elastic modulus, tensile strength, fracture strain, tangent modulus, and loading/unloading inverse tangent modulus (ITM) are obtained and adopted to characterize the mechanical properties of the composites. Microstructures of in situ grown BNNTs and tensile fracture surfaces are observed under scanning electronic microscopic (SEM). For SiC/SiC minicomposites with BNNTs, the elastic modulus, tensile strength, and fracture strain are all lower than those of SiC/SiC minicomposites without BNNTs, mainly due to high preparation temperature and the oxidation of the PyC interphase during the annealing process. Tensile stress-strain curves of SiC/SiC minicomposites with and without BNNTs are predicted using the developed micromechanical constitutive model. The predicted results agreed with experimental data. This work will provide guidance for predicting the service life of SiCf/SiC composite materials and may enable these materials to become a backbone for thermal structure systems in aerospace applications.

Effect of Ce Addition on the Microstructure and Properties of Cu-10Fe-3Ag In Situ Composite

2011 ◽  
Vol 366 ◽  
pp. 357-360 ◽  
Author(s):  
Yong Li ◽  
Rui Qing Liu ◽  
Fang Xu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Tensile Strength ◽  
High Strain ◽  
Cold Drawing ◽  
Strain Ratio ◽  
Lower Strain ◽  
Strain Hardening Rate ◽  
Conductivity Loss

Cu-10Fe-3Ag in situ composites containing (0–0.30%) Ce elements were prepared by cold drawing and intermediate heat treatments. Microstructure was observed, and mechanical properties and electrical conductivity were measured for alloys at various drawing strain ratio. Adding Ce element could reduce the size of primary Fe and Cu dendrites of Cu-10Fe-3Ag. Ultimate tensile strength increased but electrical conductivity decreased with the increase of drawing strain. Ce additions in Cu-10Fe-3Ag slightly increased the strength at low strain and effectively improved the conductivity at high strain. Both strain hardening rate and conductivity loss of Cu-10Fe-3Ag containing Ce were reduced at lower strain than Cu-10Fe-3Ag.

scholarly journals Study on Microstructure and In Situ Tensile Deformation Behavior of Fe-25Mn-xAl-8Ni-C Alloy Prepared by Vacuum Arc Melting

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 814
Author(s):  
Yaping Bai ◽  
Meng Li ◽  
Chao Cheng ◽  
Jianping Li ◽  
Yongchun Guo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Vacuum Arc ◽  
Al Content ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Tensile Deformation Behavior

In this study, Fe-25Mn-xAl-8Ni-C alloys (x = 10 wt.%, 11 wt.%, 12 wt.%, 13 wt.%) were prepared by a vacuum arc melting method, and the microstructure of this series of alloys and the in situ tensile deformation behavior were studied. The results showed that Fe-25Mn-xAl-8Ni-C alloys mainly contained austenite phase with a small amount of NiAl compound. With the content of Al increasing, the amount of austenite decreased while the amount of NiAl compound increased. When the Al content increased to 12 wt.%, the interface between austenite and NiAl compound and austenitic internal started to precipitate k-carbide phase. In situ tensile results also showed that as the content of Al increased, the alloy elongation decreased gradually, and the tensile strength first increased and then decreased. When the Al content was up to 11 wt.%, the elongation and tensile strength were 2.6% and 702.5 MPa, respectively; the results of in situ tensile dynamic observations show that during the process of stretching, austenite deformed first, and crack initiation mainly occurred at the interface between austenite and NiAl compound, and propagated along the interface, resulting in fracture of the alloy.

scholarly journals Enhanced Tensile Strength of Monolithic Epoxy with Highly Dispersed TiO2-Graphene Nanocomposites

2021 ◽  
Vol 5 (7) ◽  
pp. 191
Author(s):  
Yanshuai Wang ◽  
Siyao Guo ◽  
Biqin Dong ◽  
Feng Xing
Keyword(s):  
Tensile Strength ◽  
Epoxy Resin ◽  
Mechanical Performance ◽  
Chemical Properties ◽  
High Mechanical Property ◽  
Graphene Nanocomposites ◽  
Highly Dispersed ◽  
Dispersion State ◽  
Physical And Chemical

The functionalization of graphene has been reported widely, showing special physical and chemical properties. However, due to the lack of surface functional groups, the poor dispersibility of graphene in solvents strongly limits its engineering applications. This paper develops a novel green “in-situ titania intercalation” method to prepare a highly dispersed graphene, which is enabled by the generation of the titania precursor between the layer of graphene at room temperature to yield titania-graphene nanocomposites (TiO2-RGO). The precursor of titania will produce amounts of nano titania between the graphene interlayers, which can effectively resist the interfacial van der Waals force of the interlamination in graphene for improved dispersion state. Such highly dispersed TiO2-RGO nanocomposites were used to modify epoxy resin. Surprisingly, significant enhancement of the mechanical performance of epoxy resin was observed when incorporating the titania-graphene nanocomposites, especially the improvements in tensile strength and elongation at break, with 75.54% and 176.61% increases at optimal usage compared to the pure epoxy, respectively. The approach presented herein is easy and economical for industry production, which can be potentially applied to the research of high mechanical property graphene/epoxy composite system.

scholarly journals Interaction of Poly L-Lactide and Tungsten Disulfide Nanotubes Studied by in Situ X-ray Scattering during Expansion of PLLA/WS2NT Nanocomposite Tubes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1764
Author(s):  
Lison Rocher ◽  
Andrew S. Ylitalo ◽  
Tiziana Di Luccio ◽  
Riccardo Miscioscia ◽  
Giovanni De Filippo ◽  
...  
Keyword(s):  
Extrusion Direction ◽  
Tungsten Disulfide ◽  
Molding Process ◽  
X Ray ◽  
X Ray Scattering ◽  
Polymer Crystals ◽  
Neat Plla ◽  
Tube Expansion ◽  
Ray Scattering

In situ synchrotron X-ray scattering was used to reveal the transient microstructure of poly(L-lactide) (PLLA)/tungsten disulfide inorganic nanotubes (WS2NTs) nanocomposites. This microstructure is formed during the blow molding process (“tube expansion”) of an extruded polymer tube, an important step in the manufacturing of PLLA-based bioresorbable vascular scaffolds (BVS). A fundamental understanding of how such a microstructure develops during processing is relevant to two unmet needs in PLLA-based BVS: increasing strength to enable thinner devices and improving radiopacity to enable imaging during implantation. Here, we focus on how the flow generated during tube expansion affects the orientation of the WS2NTs and the formation of polymer crystals by comparing neat PLLA and nanocomposite tubes under different expansion conditions. Surprisingly, the WS2NTs remain oriented along the extrusion direction despite significant strain in the transverse direction while the PLLA crystals (c-axis) form along the circumferential direction of the tube. Although WS2NTs promote the nucleation of PLLA crystals in nanocomposite tubes, crystallization proceeds with largely the same orientation as in neat PLLA tubes. We suggest that the reason for the unusual independence of the orientations of the nanotubes and polymer crystals stems from the favorable interaction between PLLA and WS2NTs. This favorable interaction leads WS2NTs to disperse well in PLLA and strongly orient along the axis of the PLLA tube during extrusion. As a consequence, the nanotubes are aligned orthogonally to the circumferential stretching direction, which appears to decouple the orientations of PLLA crystals and WS2NTs.

In Situ Characterization of the Mechanical Behavior of Gecko's Spatulae by Atomic Force Microscopy

2013 ◽  
Vol 22 ◽  
pp. 85-93
Author(s):  
Shuang Yi Liu ◽  
Min Min Tang ◽  
Ai Kah Soh ◽  
Liang Hong
Keyword(s):  
Mechanical Behavior ◽  
Hierarchical Level ◽  
Intrinsic Properties ◽  
In Situ Characterization ◽  
Force Microscopy ◽  
Atomic Force ◽  
Theoretical Predictions ◽  
Multi Mode

In-situ characterization of the mechanical behavior of geckos spatula has been carried out in detail using multi-mode AFM system. Combining successful application of a novel AFM mode, i.e. Harmonix microscopy, the more detail elastic properties of spatula is brought to light. The results obtained show the variation of the mechanical properties on the hierarchical level of a seta, even for the different locations, pad and stalk of the spatula. A model, which has been validated using the existing experimental data and phenomena as well as theoretical predictions for geckos adhesion, crawling and self-cleaning of spatulae, is proposed in this paper. Through contrast of adhesive and craw ability of the gecko on the surfaces with different surface roughness, and measurement of the surface adhesive behaviors of Teflon, the most effective adhesion of the gecko is more dependent on the intrinsic properties of the surface which is adhered.

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