Investigation of the Pipe Weld for Brittle Metal Fracture

Strain rate jump tests were performed on the Fe-Mn-Cu-C TWIP Steels to determine the strain rate sensitivity, and serrated plastic flow was observed in the stress-strain curves during tensile tests at different constant strain rates ranging from 2.5×10-4S-1 to 2.5×10-2S-1. The Fe-Mn-Cu-C TWIP Steels exhibit high work hardening rate and outstanding mechanical properties, The excellent mechanical properties are attributed to dynamic strain aging(DSA) effect, which result from the interaction between Mn(Cu)-C atom atmosphere, C-vacancy, C-C pairs and moving dislocations.

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The Influence of Thermomechanical Processing Conditions on the Evolution of Microstructure and Crystallographic Textures and the Mechanical Properties of Deformed Mild Steels in the Intercritical Region

Advances in Materials Science and Engineering ◽

10.1155/2018/8298310 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7

Author(s):

Mandana Zebarjadi Sar ◽

Silvia Barella ◽

Andrea Gruttadauria ◽

Davide Mombelli ◽

Carlo Mapelli

Keyword(s):

Mechanical Properties ◽

Strain Aging ◽

Thermomechanical Processing ◽

Tensile Tests ◽

Optical Microscope ◽

Warm Rolling ◽

Consequent Reduction ◽

Intercritical Region ◽

Evolution Of Microstructure

Rolling temperature and rolling reduction intensively influence the formation of Luder lines and fluting marks in mild steels. They govern these effects through control of strain aging. In order to enhance the strain aging resistance and the consequent reduction of yield point elongation and fluting intensity, warm rolling without using the skin pass process is applied. The development of microstructure and crystallographic textures during deformation process and the determination of fluting intensity and mechanical properties consisting of tensile and formability properties in terms of different thermomechanical conditions (RT and RR%) were investigated in this study. These properties are determined through the use of bending, tensile tests, optical microscope, and EBSD analysis.

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Synthesis, Properties, and Biodegradability of Thermoplastic Elastomers Made from 2-Methyl-1,3-propanediol, Glutaric Acid and Lactide

Life ◽

10.3390/life11010043 ◽

2021 ◽

Vol 11 (1) ◽

pp. 43

Author(s):

Lamya Zahir ◽

Takumitsu Kida ◽

Ryo Tanaka ◽

Yuushou Nakayama ◽

Takeshi Shiono ◽

...

Keyword(s):

Mechanical Properties ◽

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Glutaric Acid ◽

Triblock Copolymers ◽

Tensile Tests ◽

Thermoplastic Elastomers ◽

Proteinase K ◽

Synthesis Properties

An innovative type of biodegradable thermoplastic elastomers with improved mechanical properties from very common and potentially renewable sources, poly(L-lactide)-b-poly(2-methyl-1,3-propylene glutarate)-b-poly(L-lactide) (PLA-b-PMPG-b-PLA)s, has been developed for the first time. PLA-b-PMPG-b-PLAs were synthesized by polycondensation of 2-methyl-1,3-propanediol and glutaric acid and successive ring-opening polymerization of L-lactide, where PMPG is an amorphous central block with low glass transition temperature and PLA is hard semicrystalline terminal blocks. The copolymers showed glass transition temperature at lower than −40 °C and melting temperature at 130–152 °C. The tensile tests of these copolymers were also performed to evaluate their mechanical properties. The degradation of the copolymers and PMPG by enzymes proteinase K and lipase PS were investigated. Microbial biodegradation in seawater was also performed at 27 °C. The triblock copolymers and PMPG homopolymer were found to show 9–15% biodegradation within 28 days, representing their relatively high biodegradability in seawater. The macromolecular structure of the triblock copolymers of PLA and PMPG can be controlled to tune their mechanical and biodegradation properties, demonstrating their potential use in various applications.

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Comprehensive study on mechanical properties of coated biaxial warp-knitted fabrics

Journal of Reinforced Plastics and Composites ◽

10.1177/07316844211020499 ◽

2021 ◽

pp. 073168442110204

Author(s):

Bin Yang ◽

Yingying Shang ◽

Zeliang Yu ◽

Minger Wu ◽

Youji Tao ◽

...

Keyword(s):

Mechanical Properties ◽

Failure Modes ◽

Least Squares Method ◽

Tensile Tests ◽

Tensile Creep ◽

Base Layer ◽

Sustained Load ◽

Uniaxial Tensile ◽

Membrane Structures ◽

Knitted Fabrics

In recent years, coated fabrics have become the major material used in membrane structures. Due to the special structure of base layer and mechanical properties, coated biaxial warp-knitted fabrics are increasingly applied in pneumatic structures. In this article, the mechanical properties of coated biaxial warp-knitted fabrics are investigated comprehensively. First, off-axial tensile tests are carried out in seven in-plane directions: 0°, 15°, 30°, 45°, 60°, 75°, and 90°. Based on the stress–strain relationship, tensile strengths are obtained and failure modes are studied. The adaptability of Tsai–Hill criterion is analyzed. Then, the uniaxial tensile creep test is performed under 24-h sustained load and the creep elongation is calculated. Besides, tearing strengths in warp and weft directions are obtained by tearing tests. Finally, the biaxial tensile tests under five different load ratios of 1:1, 2:1, 1:2, 1:0, and 0:1 are carried out, and the elastic constants and Poisson’s ratio are calculated using the least squares method based on linear orthotropic assumption. Moreover, biaxial specimens under four load ratios of 3:1, 1:3, 5:1, and 1:5 are further tensile tested to verify the adaptability of linear orthotropic model. These experimental data offer a deeper and comprehensive understanding of mechanical properties of coated biaxial warp-knitted fabrics and could be conveniently adopted in structural design.

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Influence of Hydrostatic Extrusion on the Mechanical Properties of the Model Al-Mg Alloys

Journal of Materials Engineering and Performance ◽

10.1007/s11665-021-05628-0 ◽

2021 ◽

Author(s):

Aleksandra Towarek ◽

Wojciech Jurczak ◽

Joanna Zdunek ◽

Mariusz Kulczyk ◽

Jarosław Mizera

Keyword(s):

Mechanical Properties ◽

Plastic Deformation ◽

Tensile Strength ◽

Microstructural Analysis ◽

Tensile Tests ◽

Hydrostatic Extrusion ◽

Microstructure Formation ◽

Initial State ◽

Degree Of Deformation ◽

Al Mg Alloys

AbstractTwo model aluminium-magnesium alloys, containing 3 and 7.5 wt.% of Mg, were subjected to plastic deformation by means of hydrostatic extrusion (HE). Two degrees of deformation were imposed by two subsequent reductions of the diameter. Microstructural analysis and tensile tests of the materials in the initial state and after deformation were performed. For both materials, HE extrusion resulted in the deformation of the microstructure—formation of the un-equilibrium grain boundaries and partition of the grains. What is more, HE resulted in a significant increase of tensile strength and decrease of the elongation, mostly after the first degree of deformation.

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Mimicking the Mechanical Properties of Aortic Tissue with Pattern-Embedded 3D Printing for a Realistic Phantom

Materials ◽

10.3390/ma13215042 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5042

Author(s):

Jaeyoung Kwon ◽

Junhyeok Ock ◽

Namkug Kim

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

3D Printing ◽

Mechanical Characteristics ◽

Aortic Wall ◽

Tensile Tests ◽

Human Aorta ◽

Aortic Tissue ◽

Medical Field ◽

Base Materials

3D printing technology has been extensively applied in the medical field, but the ability to replicate tissues that experience significant loads and undergo substantial deformation, such as the aorta, remains elusive. Therefore, this study proposed a method to imitate the mechanical characteristics of the aortic wall by 3D printing embedded patterns and combining two materials with different physical properties. First, we determined the mechanical properties of the selected base materials (Agilus and Dragonskin 30) and pattern materials (VeroCyan and TPU 95A) and performed tensile testing. Three patterns were designed and embedded in printed Agilus–VeroCyan and Dragonskin 30–TPU 95A specimens. Tensile tests were then performed on the printed specimens, and the stress-strain curves were evaluated. The samples with one of the two tested orthotropic patterns exceeded the tensile strength and strain properties of a human aorta. Specifically, a tensile strength of 2.15 ± 0.15 MPa and strain at breaking of 3.18 ± 0.05 mm/mm were measured in the study; the human aorta is considered to have tensile strength and strain at breaking of 2.0–3.0 MPa and 2.0–2.3 mm/mm, respectively. These findings indicate the potential for developing more representative aortic phantoms based on the approach in this study.

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Strength Enhancement of Superduplex Stainless Steel Using Thermomechanical Processing

Metals ◽

10.3390/met11071094 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1094

Author(s):

M. A. Lakhdari ◽

F. Krajcarz ◽

J. D. Mithieux ◽

H. P. Van Landeghem ◽

M. Veron

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Thermomechanical Processing ◽

Tensile Tests ◽

Image Correlation ◽

Strength Enhancement ◽

Industrial Material ◽

Superduplex Stainless Steel ◽

The Impact ◽

Strength Improvement

The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out in order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, were used to characterize the morphology and the preferred orientations of ferrite and austenite in all microstructures. Additionally, the mechanical properties were assessed by tensile tests with digital image correlation. Phase morphology was not found to significantly affect the mechanical properties and neither were phase volume fractions within 13% of the 50/50 ratio. Austenite texture was the same combined Goss/Brass texture regardless of thermomechanical processing, while ferrite texture was mainly described by α-fiber orientations. Ferrite texture and average phase spacing were found to have a notable effect on mechanical properties. One of the original microstructures of superduplex stainless steel obtained here shows a strength improvement by the order of 120 MPa over the industrial material.

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Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

Sustainability ◽

10.3390/su13105494 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5494

Author(s):

Lucie Kucíková ◽

Michal Šejnoha ◽

Tomáš Janda ◽

Jan Sýkora ◽

Pavel Padevět ◽

...

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

Cross Section ◽

Negative Impact ◽

Tensile Tests ◽

Thermal Recovery ◽

Bending Test ◽

Small Scale ◽

Spruce Wood ◽

The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽

10.3390/ma13051242 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1242

Author(s):

Olga Mysiukiewicz ◽

Paulina Kosmela ◽

Mateusz Barczewski ◽

Aleksander Hejna

Keyword(s):

Mechanical Properties ◽

Melt Flow Index ◽

Tensile Tests ◽

Mechanical Analysis ◽

Flow Index ◽

Scanning Calorimetry ◽

Metal Composites ◽

Pre Treatment ◽

The Impact ◽

Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

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New Approach In The Properties Evaluation Of Ultrafine-Grained OFHC Copper

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0180 ◽

2015 ◽

Vol 60 (2) ◽

pp. 605-614 ◽

Cited By ~ 2

Author(s):

T. Kvačkaj ◽

A. Kováčová ◽

J. Bidulská ◽

R. Bidulský ◽

R. Kočičko

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Tensile Tests ◽

Coarse Grained ◽

Wear Behaviour ◽

Ofhc Copper ◽

Strain Rates ◽

Ultrafine Grained ◽

Reduction Of Area ◽

Pin On Disk

AbstractIn this study, static, dynamic and tribological properties of ultrafine-grained (UFG) oxygen-free high thermal conductivity (OFHC) copper were investigated in detail. In order to evaluate the mechanical behaviour at different strain rates, OFHC copper was tested using two devices resulting in static and dynamic regimes. Moreover, the copper was subjected to two different processing methods, which made possible to study the influence of structure. The study of strain rate and microstructure was focused on progress in the mechanical properties after tensile tests. It was found that the strain rate is an important parameter affecting mechanical properties of copper. The ultimate tensile strength increased with the strain rate increasing and this effect was more visible at high strain rates$({\dot \varepsilon} \sim 10^2 \;{\rm{s}}^{ - 1} )$. However, the reduction of area had a different progress depending on microstructural features of materials (coarse-grained vs. ultrafine-grained structure) and introduced strain rate conditions during plastic deformation (static vs. dynamic regime). The wear behaviour of copper was investigated through pin-on-disk tests. The wear tracks examination showed that the delamination and the mild oxidational wears are the main wear mechanisms.

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