Development of In Situ-Formed Interconnected Porous Scaffolds with Low Porosity

2007 ◽  
Vol 361-363 ◽  
pp. 415-418
Author(s):  
Yu Lin Li ◽  
Masanori Kikuchi
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Polymethyl Methacrylate ◽  
Carboxymethyl Cellulose ◽  
Water Soluble ◽  
Wet Spinning ◽  
Porous Scaffolds ◽  
Volume Percent ◽  
Kneading Method

Biocompatible and water-soluble fibers (sodium carboxymethyl cellulose (CMC)) were fabricated via a wet-spinning method. The CMC fibers/ polymethyl methacrylate (PMMA) mixtures and CMC fibers/Poly (L-lactide-co-glycolide-co- -caprolactone) (PLGC) mixtures were prepared by a heat-kneading method. For CMC fibers/PMMA, after removal of the CMC fibers from the mixtures, the interconnected porous scaffolds with porosity from 27.79 % to 60.98 % (volume percent) were obtained. For CMC fibers/PLGC, the interconnected porous scaffolds with porosity 38.55 % and 76.83 % (volume percent) were prepared. The solid CMC fibers/PLGC mixtures had the higher ultimate tensile strength and Young, s modulus than those of porous PLGC scaffolds.

Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments

1981 ◽  
Vol 12 ◽  
Author(s):  
J. Bevk ◽  
W. A. Sunder ◽  
G. Dublon ◽  
David E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Size Dependence ◽  
Young's Modulus ◽  
Plastic Properties ◽  
Young’S Moduli ◽  
Lattice Softening

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.

Novel nanocomposite hydrogel for wound dressing and other medical applications

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103036-103046 ◽  
Author(s):  
Ali Hebeish ◽  
S. Sharaf
Keyword(s):  
Carboxymethyl Cellulose ◽  
Wound Dressing ◽  
Graft Copolymerization ◽  
Crosslinking Agent ◽  
Water Soluble ◽  
Medical Applications ◽  
Nanocomposite Hydrogel ◽  
Hydrogel Nanocomposites

Graft copolymerization of DADMAC with a MBA crosslinking agent was achieved on water soluble carboxymethyl cellulose with an APS initiator. A CuO nanocomposite hydrogel was formed in situ on cotton. The synthesis of Ag/CMC-DADMAC hydrogel nanocomposites was also studied.

Effects of Yttrium on Microstructure and Mechanical Properties of In Situ (Al2O3+Al3Zr)p/A356 Composites

2010 ◽  
Vol 152-153 ◽  
pp. 1083-1087
Author(s):  
Bo Wang ◽  
Yu Tao Zhao ◽  
Song Li Zhang ◽  
Gang Chen ◽  
Xiao Nong Cheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Test Results ◽  
Microstructure And Mechanical Properties ◽  
Yttrium Addition

In-situ (Al2O3+Al3Zr)p/A356 composites were synthesized by melt reaction technology and the effects of yttrium on microstructure and mechanical properties of the composites are investigated. The results indicate that the reinforced particulates Al2O3 and Al3Zr become smaller in size with yttrium addition, the sizes are about 0.5~2μm. The distribution becomes more homogeneous, the morphologies are spheroid-shape and ellipsoid-shape, the ambitus is blunt. The mechanical properties test results show the mechanical properties of the composites are greatly enhanced. With 0.4wt.% yttrium addition, the ultimate tensile strength and yield strength of the composites reach to 388MPa and 296MPa, which are increased 35.6% and 37.0% comparing with no yttrium addition, respectively. The effect mechanisms of yttrium are discussed.

scholarly journals In Situ Development and High Temperature Features of CoCrFeNi-M6Cp High Entropy-Alloy Based Hardmetal

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 408
Author(s):  
Huizhong Li ◽  
He Lin ◽  
Xiaopeng Liang ◽  
Weiwei He ◽  
Bin Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Volume Fraction ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Average Grain Size ◽  
Carbide Particles

In this work, an in-situ CoCrFeNi-M6Cp high entropy-alloy (HEA) based hardmetal with a composition of Co25Cr21Fe18Ni23Mo7Nb3WC2 was fabricated by the powder metallurgy (PM) method. Microstructures and mechanical properties of this HEA were characterized and analyzed. The results exhibit that this HEA possesses a two-phase microstructure consisting of the face-centered cubic (FCC) matrix phase and the carbide M6C phase. This HEA has an average grain size of 2.2 μm, and the mean size and volume fraction of carbide particles are 1.2 μm and 20%. The tensile tests show that the alloy has a yield strength of 573 MPa, ultimate tensile strength of 895 MPa and elongation of 5.5% at room temperature. The contributions from different strengthening mechanisms in this HEA were calculated. The grain boundary strengthening is the dominant strengthening mechanism, and the carbide particles are significant for the further enhancement of yield strength by the dislocation strengthening and Orowan strengthening. In addition, with increasing temperatures from 600 °C to 900 °C, the HEA shows a reduced yield strength (YS) from 473 MPa to 142 MPa, a decreased ultimate tensile strength (UTS) from 741 MPa to 165 MPa and an enhanced elongation from 10.5% to 31%.

scholarly journals In-Situ SEM Observation on Fracture Behavior of Titanium Alloys with Different Slow-Diffusing β Stabilizing Elements

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1848
Author(s):  
Wenjing Zhang ◽  
Haofeng Xie ◽  
Songxiao Hui ◽  
Wenjun Ye ◽  
Yang Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Tensile Deformation ◽  
Three Dimensional ◽  
Atom Probe ◽  
Β Phase ◽  
Phase Size ◽  
Bcc Structure ◽  
Hcp Structure

The fracture-behaviors of two Ti-Al-Sn-Zr-Mo-Nb-W-Si alloys with different slow-diffusing β stabilizing elements (Mo, W) were investigated through in-situ tensile testing at 650 °C via scanning electron microscopy. These alloys have two phases: the α phase with hcp-structure (a = 0.295 nm, c = 0.468 nm) and the β phase with bcc-structure (a = 0.332 nm). Three-dimensional atom probe (3DAP) results show that Mo and W mainly dissolve in the β phase, and they tend to cluster near the α/β phase boundary. Adding more slow-diffusing β stabilizing elements can improve the ultimate tensile strength and elongation of the alloy at 650 °C. During tensile deformation at 650 °C, microvoids mainly initiate at α/β interfaces. With increases in the contents of Mo and W, the β phase content increases and the average phase size decreases, which together have excellent accommodative deformation capability and will inhibit the microvoids’ nucleation along the interface. In addition, the segregation of Mo and W near the α/β interface can reduce the diffusion coefficient of the interface and inhibit the growth of microvoids along the interface, which are both helpful to improve the ultimate tensile strength and plasticity.

Microstructure and Mechanical Property of an ECAP Processed Al-Mg2Si In Situ Composite by Using a Combined Route

2011 ◽  
Vol 194-196 ◽  
pp. 1720-1723 ◽  
Author(s):  
Li Ping Bian ◽  
Wei Liang ◽  
Wen Li Zhang
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Pressing ◽  
Angular Pressing ◽  
Elongation To Failure ◽  
Microstructure And Mechanical Property ◽  
Al Matrix

Microstructure and mechanical property of a hypoeutectic Al-Mg2Si composite processed by equal channel angular pressing up to eight passes in a combined route 2A+4BA+2A were investigated. The results show that the initial developed eutectic Mg2Si was significantly refined into submicrometer-scale particles and distributed homogeneously in the Al matrix, which together with the refinement of Al matrix leads to a much higher ductility with the elongation to failure up to 24% and a significantly enhanced ultimate tensile strength of 284MPa in the processed composite, increased by 2300% and 70%, respectively, compared to those in its as-cast counterpart.

Microstructure and Mechanical Properties of TiB2/Al Composites

2011 ◽  
Vol 399-401 ◽  
pp. 2266-2270 ◽  
Author(s):  
Shuai Chen ◽  
Yu Tao Zhao ◽  
Hua Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Phase Composition ◽  
Ultimate Tensile Strength ◽  
Master Alloy ◽  
Volume Fraction ◽  
Matrix Material ◽  
The Matrix ◽  
Ti Powder

Abstract:TiB2/Al composites were prepared by the melt in situ reaction fabrication using Al-3B master alloy and Ti powder as the reactive materials. The phase composition and the microstructure of the as-prepared composites were investigated by XRD, SEM. The results indicate that the reinforcements are TiB2 and a small amount of Al3Ti. TiB2particles are in the shape of irregular polygon or rectangle, and its size is 0.5-2μm. Compared with the matrix material, the ultimate tensile strength, microhardness of as-prapred composites increase by 51%, 68.8%, 85.2%, and 33.4%, 43.8%, 55%, respectively. However, the elongation decrease with the volume fraction of the reinforcements increased.

Effect of fluxes on Sn-Zn-Bi solder alloys on copper substrate

2017 ◽  
Vol 29 (4) ◽  
pp. 225-234 ◽  
Author(s):  
Ervina Efzan Mhd Noor ◽  
Ayodeji Samson Ogundipe
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Mechanical Tests ◽  
Water Soluble ◽  
Solder Alloys ◽  
Content Type

Purpose This paper aims to investigate the effect different fluxes have on the mechanical properties of lead-free solders, specifically Sn-Zn-Bi solder alloy. The solder billets were soldered in between copper substrates and flux was applied. The mechanical tests carried out on the solder alloys were tensile and shear tests. They were experimented on with different fluxes, namely, water-soluble (paste), rosin mildly activated (RMA) and insoluble (RMA) flux. From these experiments, the ultimate tensile strength, shear strength, elongation, yield stress, Young’s modulus and the stress-strain curve are derived. The results showed that solder billets that were soldered onto copper substrates with water-soluble flux yielded the highest ultimate tensile strength and shear strength values of 9.9961 MPa and 118.836 MPa, respectively. Billets soldered using RMA flux had the highest values of elongation and Young’s modulus, 0.306 mm and 50,257.295 MPa, respectively. However, on viewing the failure of all the specimens under an optical microscope and scanning electron microscope (SEM), specimens soldered using water-soluble flux possessed the least deformities, depicting their higher level of mechanical properties, entailing their strength and ductility, deeming them as the most suitable flux for microelectronic applications. Design/methodology/approach The solder billets were soldered in between copper substrates and flux was applied. The mechanical tests carried out on the solder alloys were tensile and shear tests. They were experimented on with different fluxes, namely, water-soluble (paste), RMA and insoluble flux (RMA) flux. From these experiments, the ultimate tensile strength, shear strength, elongation, yield stress, Young’s modulus and the stress-strain curve are derived. Findings The results showed that solder billets that were soldered onto copper substrates with water-soluble flux yielded the highest ultimate tensile strength and shear strength values of 9.9961 MPa and 118.836 MPa, respectively. Originality/value This paper demonstrated that water-soluble fluxes gave the better strength and were most suitable for microelectronics applications.

scholarly journals In Situ estimate of ultimate tensile strength for part optimization in extrusion-based additive manufacturing

2020 ◽  
Vol 1633 ◽  
pp. 012159
Author(s):  
Sadegh Nouri Gooshki ◽  
Fabian Hough ◽  
Damas W Limoge ◽  
Aswin Raghav Nirmaleswaran ◽  
Vadim Pinsky ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Additive Manufacturing ◽  
Ultimate Tensile Strength

Tensile Properties of 15wt. %TiB2/7055 Composite Fabricated by In Situ Method

2013 ◽  
Vol 842 ◽  
pp. 165-169 ◽  
Author(s):  
Dong Chen ◽  
Cong Zou ◽  
Yi Jie Zhang ◽  
Nai Heng Ma ◽  
Hao Wei Wang
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Matrix Alloy ◽  
In Situ Method ◽  
The Matrix ◽  
7055 Aluminum Alloy

7055 aluminum alloy reinforced with 15wt. % TiB2 particulates was synthesized by in situ method, the microstructure and tensile properties were investigated. There are a few particulate clusters in the matrix. The elastic modulus and hardness of the composite are higher than that of the matrix alloy, but the yield strength and ultimate tensile strength decrease. The decrease of strength is attributed to the presence of TiB2 particulate cluster and residual reaction slag.

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