scholarly journals Post-Processing Treatment Impact on Mechanical Properties of SLM Deposited Ti-6Al-4 V Porous Structure for Biomedical Application

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5167
Author(s):  
Eren Pehlivan ◽  
Jan Džugan ◽  
Jaroslav Fojt ◽  
Radek Sedláček ◽  
Sylwia Rzepa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Structural Damage ◽  
Biomedical Application ◽  
Hot Isostatic Pressing ◽  
Minor Effect ◽  
Porous Structures ◽  
Compression Tests ◽  
Strut Thickness ◽  
Surface Etching

Additive manufacturing technologies allow producing a regular three-dimensional mesh of interconnected struts that form an open-cell porous structure. Regular porous structures have been used in the orthopedic industry due to outstanding bone anchoring. The aim of the study was to determine how the postprocessing influences the mechanical properties of porous structures made of titanium alloy CL 41TI ELI. The effect of hot isostatic pressing (HIP) as a method of increasing microstructural integrity was investigated here. The influence of surface etching (SE) technique, which was applied to the porous structure for cleaning unmelted titanium powder particles on the surface of connectors from the inner surfaces of a porous structure, was examined in this study. Mechanical properties were investigated by means of compression tests. The results point out that HIP has a minor effect on the mechanical behavior of considered porous structures. The SE is an effective method to clean the surface of a porous structure, which is very important in the case of biomedical applications when loose powder can cause serious health problems. Another effect of the SE is also the strut thickness reduction. Reducing strut thickness of a porous structure with the surface etching decreases its stiffness to the same extent as predicted by the relative density theoretical model but did not result in structural damage.

scholarly journals GEOMETRY AND MECHANICAL PROPERTIES OF A 3D-PRINTED TITANIUM MICROSTRUCTURE

2018 ◽  
Vol 15 ◽  
pp. 104-108
Author(s):  
Luboš Řehounek ◽  
Petra Hájková ◽  
Petr Vakrčka ◽  
Aleš Jíra
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Uniaxial Compression ◽  
Elastic Moduli ◽  
Weight Ratio ◽  
Porous Structures ◽  
Compression Tests ◽  
Local Material ◽  
3D Printed ◽  
Titanium Microstructure

Construction applications sometimes require use of a material other than construction steel or concrete – mainly in cases, where strength to weight ratio needs to be considered. A suitable solution to this problem are structures manufactured using the 3D printing process, as they have a very good strength to weight ratio (i.e.: Ti-6Al-4V – σ<sub>ult</sub> = 900 MPa and ρ = 4500 kg/m<sup>3</sup>). Trabecular structures are porous structures with local material characteristics identical to their commonly manufactured counterparts, but due to their geometry, they have different global mechanical properties and are suited for special applications. We designed and manufactured six variants of these structures and subjected them to uniaxial compression tests, nanoindentation tests and subsequently evaluated their differences and elastic moduli. The values of global moduli E are in the range of 2.55 GPa – 3.55 GPa for all specimens.

Hot isostatic pressing synthesis and mechanical properties of Al/Al–Cu–Fe composite materials

2008 ◽  
Vol 23 (4) ◽  
pp. 904-910 ◽  
Author(s):  
T. El Kabir ◽  
A. Joulain ◽  
V. Gauthier ◽  
S. Dubois ◽  
J. Bonneville ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Hot Isostatic Pressing ◽  
Constant Strain Rate ◽  
Rate Sensitivity ◽  
Icosahedral Phase ◽  
Compression Tests ◽  
Isostatic Pressing ◽  
Temperature Regimes ◽  
Mechanism Control

Metal-matrix composites are produced from Al powder and 30 vol% of icosahedral Al–Cu–Fe quasi-crystalline particles using a hot isostatic pressing technique. It is demonstrated that the initial icosahedral phase is transformed into the ω-Al70Cu20Fe10 tetragonal phase during the hot isostatic pressing (HIP) process. The mechanical properties of the composite were evaluated over the temperature range 293 to 773 K by performing compression tests at constant strain rate. The temperature dependence of the yield stress gives evidence of two temperature regimes with a transition temperature at approximately 423 K. Strain-rate sensitivity measurements support the change in rate-controlling deformation mechanisms at this temperature. It is proposed that cross-slip and/or climb mechanism control plastic flow. Finally, it is suggested that the phase transformation of the particle contributes positively to the improvement of the mechanical properties.

Highly Glycerin-Loaded Natural Rubber Films Prepared by Casting Technique Using Different Solvents

2013 ◽  
Vol 844 ◽  
pp. 190-193 ◽  
Author(s):  
Pongsathorn Issarayungyuen ◽  
Wiwat Pichayakorn ◽  
Thawatchai Phaechamud
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Porous Structure ◽  
Diethyl Ether ◽  
Drug Delivery Systems ◽  
Controlled Drug Delivery ◽  
Porous Structures ◽  
Casting Technique

The highly glycerin-loaded natural rubber (NR) films were fabricated by casting technique with different solvents including dichloromethane (DCM), diethyl ether and tetrahydrofuran (THF) with an addition of 75 phr glycerin. Their mechanical properties, wettability and topography were determined. The highly glycerin-loaded NR films exhibited the continuous porous structure which their tensile strength values decreased whereas their wettability was enhanced. Pore size of the glycerin-loaded NR films prepared by using DCM as a solvent was greatly larger than those of the systems prepared by using diethyl ether and THF, respectively. Some active compounds might be loaded into these modified porous structures of NR films and applied for controlled drug delivery systems.

scholarly journals A Phenomenological Approach to Study Mechanical Properties of Polymeric Porous Structures Processed Using Supercritical CO2

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 485 ◽  
Author(s):  
Antonio Tabernero ◽  
Lucia Baldino ◽  
Stefano Cardea ◽  
Eva Martín del Valle ◽  
Ernesto Reverchon
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Cellulose Acetate ◽  
Polymer Network ◽  
Phenomenological Approach ◽  
Porous Structures ◽  
Compression Tests ◽  
Energy Functions ◽  
Realistic Description ◽  
Strain Energy Functions

This work proposes a modeling of the mechanical properties of porous polymers processed by scCO2, using a phenomenological approach. Tensile and compression tests of alginate/gelatin and cellulose acetate/graphene oxide were modeled using three hyperelastic equations, derived from strain energy functions. The proposed hyperelastic equations provide a fair good fit for mechanical behavior of the nanofibrous system alginate/gelatin (deviations lower than 10%); whereas, due to the presence of the solid in the polymer network, a four-parameter model must be used to fit the composite cellulose acetate/graphene oxide behavior. Larger deviations from the experimental data were observed for the system cellulose acetate/graphene oxide because of its microporous structure. A finite element method was, then, proposed to model both systems; it allowed a realistic description of observable displacements and effective stresses. The results indicate that materials processed using scCO2, when submitted to large stresses, do not obey Hooke´s law and must be considered as hyperelastic.

Mechanical properties of multi-materials porous structures based on triply periodic minimal surface fabricated by additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mingkang Zhang ◽  
Yongqiang Yang ◽  
Meizhen Xu ◽  
Jie Chen ◽  
Di Wang
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Plastic Material ◽  
Porous Structures ◽  
Compression Force ◽  
Content Type ◽  
Periodic Minimal Surface ◽  
Triply Periodic ◽  
Force Direction ◽  
Triply Periodic Minimal Surface

Purpose The purpose of this study is focused on the mechanical properties of multi-materials porous structures manufactured by selective laser melting (SLM). Design/methodology/approach The Diamond structure was designed by the triply periodic minimal surface function in MATLAB, and multi-materials porous structures were manufactured by SLM. Compression tests were applied to analyze the anisotropy of mechanical properties of multi-materials porous structures. Findings Compression results show that the multi-materials porous structure has a strong anisotropy behavior. When the compression force direction is parallel to the material arrangement, multi-materials porous structure was compressed in a layer-by-layer way, which is the traditional deformation of the gradient structure. However, when the compression force direction is perpendicular to the material arrangement, the compression curves show a near-periodic saw-tooth waveform characteristic, and this kind of structure was compressed consistently. It is demonstrated that the combination with high strength brittle material and low strength plastic material improves compression mode, and plastic material plays a role in buffering fracture. Originality/value This research provides a new method for the design and manufacturing of multi-materials porous structures and an approach to change the compression behavior of the porous structure.

scholarly journals Three-dimensional highly conductive silver nanowires sponges based on cotton-templated porous structures for stretchable conductors

RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Chun-Hua Zhu ◽  
Li-Ming Li ◽  
Jian-Hua Wang ◽  
Ye-Ping Wu ◽  
Yu Liu
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Silver Nanowires ◽  
Three Dimensional ◽  
Porous Structures ◽  
Binary Structure ◽  
Stretchable Conductors ◽  
Stretchable Conductor

A stretchable conductor was explored by embedding a binary structure fabricated from an interconnected porous structure of cotton as skeleton along with supported 2D AgNWs network into PDMS, which showed excellent electrical and mechanical properties.

Mechanical Properties Improvement of Porous Titanium-Bioglass Nanocomposites by Mechanical Alloying

2013 ◽  
Vol 829 ◽  
pp. 319-323
Author(s):  
Saeed Riahi ◽  
Mohammad Rajabi ◽  
Sayed Mahmood Rabiee
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Biomedical Application ◽  
Diffraction Method ◽  
Porous Titanium ◽  
Sintering Process ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Space Holder

In this study, porous titanium-10 wt.% bioglass nanocomposites were fabricated by the combination of mechanical alloying and a space holder sintering process. The mixed powders were mechanically alloyed for 15 h. The blended Ti-Bioglass was mixed with 30 wt.% carbamide as a space holder. The mixtures were uniaxially pressed and finally, the green compacts sintered at 1150°C for 5 hours. The porous structures are characterized by X-ray diffraction method (XRD) and scanning electron microscopy (SEM). The mechanical properties were examined using micro hardness and compression tests. The investigation revealed that after 15 h of milling, the Bioglass dissolved in Ti lattice. Also, results show that nanostructured Ti-10 wt.% Bioglass with 31.5 nm crystallite size possess greater hardness compared to respective microcrystalline titanium and desirable compressive strength for using in biomedical application.

Processing and Characterization of Graphite Nanofibers Reinforced Aluminum Matrix Composites

2006 ◽  
Vol 306-308 ◽  
pp. 1067-1072
Author(s):  
Jun Ho Jang ◽  
Kwang Hwan Oh ◽  
S.I. Heo ◽  
Kyung Seop Han
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Compression Tests ◽  
Thermal Tests ◽  
Graphite Nanofibers

Graphite nanofibers (GNFs) reinforced aluminum matrix composites have been fabricated successfully by powder metallurgy methods. The GNF-Al mixtures were prepared through ultrasonication and ball milling. The GNF-Al composites were consolidated by hot isostatic pressing (HIP) and then a high density of compacts could be obtained. The microstructure and the distribution of nanofibers in matrix material were investigated by microscopy observations. A uniform distribution of nanofibers in aluminum matrix was obtained. The mechanical properties were measured by microhardness and compression tests. The optimal contents of nanofibers were determined in view of the mechanical properties. The results of thermal tests indicate that the addition of nanofibers were enhanced the thermal conductivity but, the dimensional stability such as thermal expansion was not improved significantly.

Preparation and characterization of porous hydroxyapatite pellets: Effects of calcination and sintering on the porous structure and mechanical properties

2016 ◽  
Vol 230 (6) ◽  
pp. 985-993 ◽  
Author(s):  
Onder Albayrak ◽  
Mehmet Ipekoglu ◽  
Nazim Mahmutyazicioglu ◽  
Mehmet Varmis ◽  
Emrah Kaya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Porous Structures ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Porous Hydroxyapatite ◽  
Urea Content ◽  
Hydroxyapatite Powder ◽  
Density Values

In this study, porous hydroxyapatite structures were produced by using urea particles of 600–850 µm size. Samples with two different urea composition (25 and 50 wt%) were prepared along with samples without any urea content by adding urea to commercially available hydroxyapatite in its as purchased and calcined states. The produced pellets were sintered at 1100 ℃ and 1200 ℃ for 2 h. Compression tests and microhardness measurements were conducted and changes in density values were examined in order to determine the effect of the calcination state of the prior hydroxyapatite powder, the sintering temperature and the amount of urea added. Also X-ray diffraction, Fourier transform infrared, and scanning electron microscopy analyses were conducted to determine the phase stability, functional groups, and pore morphology, respectively. Calcination is found to negatively affect the densification and sinterability of the produced samples, resulting in a decrease of compressive strength and microhardness. With the control of the urea content and sintering temperature uncalcined hydroxyapatite can successfully be used to tailor the density and mechanical properties of the final porous structures.

scholarly journals Microstructures and Mechanical Properties of Two-Phase Alloys Based on NbCr2

1998 ◽  
Vol 552 ◽  
Author(s):  
Katherine C. Chen ◽  
Paul G. Kotula ◽  
Carl M. Cady ◽  
Michael E. Mauro ◽  
Dan J. Thoma
Keyword(s):  
Mechanical Properties ◽  
Hot Isostatic Pressing ◽  
Processing Technique ◽  
Compression Tests ◽  
Two Phase ◽  
Static Compression ◽  
Precursor Phase ◽  
Microstructures And Mechanical Properties ◽  
Novel Processing ◽  
Quasi Static Compression

ABSTRACTA two-phase, NbCrTi alloy (bce + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature and microstructure.

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