Effect Of Silver Addition Research Articles

The effect of Silver addition and deformation parameters on mechanostructure, biodegradation, antimicrobial and mechanical properties of Zn-based biodegradable alloys.

Although low mechanical properties, Zinc (Zn) alloy systems with Copper (Cu) and Silver (Ag) as alloying elements have strong biocompatibility and biodegradability characteristics. This study examined the effects of rolling parameters and Ag alloying on the mechanical, biodegradable, and final structure of an alloy based on Zn. Comparing treated and untreated specimens, the addition of Ag led to a considerable improvement in both hardness and compressive strength. The produced alloys with varying amounts of Ag (between 1 and 4wt%) were cold rolled at 400-800r/min and friction coefficients between 0.3 and 0.5. The alloys' ultimate strength rose with an increase in rolling speed for Zn1Cu4Ag, and hardness and compressive strengths rose to 80HV and 470MPa, respectively. It was demonstrated that rolling force rose somewhat with Ag concentration but significantly increased with rolling speed and friction. E. Coli and S. aureus were used to assess the biodegradable alloys' antibacterial properties. For the Zn-1Cu-2Ag alloy, the inclusion of Ag resulted in a considerable (50%) rise in antibacterial activity that exceeded the effects seen in other alloy systems.

Effect of Silver Addition on Microstructure, Phase Composition, Microhardness and Surface Oxide Layer Formation of Al0.5CoCrCu0.5FeNi and Al0.5CoCrCuFeNi High-Entropy Alloys

Effect of Silver Addition on Microstructure, Phase Composition, Microhardness and Surface Oxide Layer Formation of Al0.5CoCrCu0.5FeNi and Al0.5CoCrCuFeNi High-Entropy Alloys

Effect of Silver Addition on Cu-based Shape Memory Alloys

Effect of Silver Addition on Cu-based Shape Memory Alloys

EFFECT OF SILVER ADDITION TO HIGH-ENTROPY ALLOYS AL0.5COCRCU0.5FENI AND AL0.5COCRCUFENI ON THEIR MICROSTRUCTURE, PHASE COMPOSITION, MICROHARDNESS AND SURFACE OXIDE LAYER FORMATION

High-entropy alloys (HEAs) consisting of five or more components in an equimolar ratio are attracting increasing attention due to a unique combination of various properties. Alloying HEAs with small amounts of certain elements (most often rare earth, trace or noble metals) is a promising way to improve the characteristics of such alloys and control their properties. This paper reports the results on the microstructure, phase composition, and microhardness of cast AgxAl0.5CoCrCuyFeNi HEAs (x = 0, 0.1; y = 0.5, 1.0). The effect of silver addition on the oxidation behavior of the studied HEAs at 700°C was determined. The morphology, phase and chemical composition of the resulting oxide film were studied. It was shown that the introduction of silver improves the mechanical characteristics of the alloys, but deteriorates the oxidation resistance due to the formation of copper-silver eutectic in the alloy microstructure, leading to a change in the morphology and phase composition of the formed oxide layer. Along with the solid solution of (Al, Cr)2O3 oxides and CuCr2O4, NiCr2O4 spinels, the addition of silver leads to the formation of copper oxide CuO and a small amount of silver oxide Ag2O in the surface film.

Effects of Silver Addition in Zinc Oxide Nanoparticles on Films of HMSPP/SEBS against Staphylococcus aureus and Escherichia coli Contamination

Effects of Silver Addition in Zinc Oxide Nanoparticles on Films of HMSPP/SEBS against Staphylococcus aureus and Escherichia coli Contamination

Effect of silver additions on the microstructure, mechanical properties and corrosion behavior of biodegradable Fe-30Mn-6Si

FeMn-based alloys are promising materials for vascular implant applications, especially due to their superior mechanical properties and excellent processability. However, a further increase of the biodegradation rate of these metallic materials is desired. The addition of silver was reported to be a promising approach for accelerating the corrosion rate of those FeMn-based alloys by promoting local corrosion due to galvanic coupling, besides improving their antibacterial properties. On the other hand, the corrosion mechanisms occurring due to silver addition in various FeMn-based systems have not been understood completely. In this study, the effect of different silver contents (0.6 wt% and 1.2 wt%) on the microstructure, mechanical and corrosion properties of a cast biodegradable Fe-30Mn-6Si (wt%) is presented. By silver addition, finely distributed Ag-rich precipitates are formed in the matrix composed of austenite and ɛ-martensite, which could be detected by investigations with scanning electron and transmission electron microscopy as well as X-ray diffraction. Furthermore, an enhanced ɛ-martensite fraction was observed with rising Ag content. These changes in the microstructure significantly influence the corrosion properties. By means of potentiodynamic polarization measurements in a simulated body fluid (SBF) at 37 °C, it was revealed that the Ag additions reduce the corrosion current density, which indicates a decreased corrosion rate in comparison to Fe-30Mn-6Si. However, the alloy modifications still show higher corrosion current densities than a cast Fe-30Mn reference system. In addition, higher yield strengths for Ag-added alloys were detected by quasi-static tensile and compression tests. Data availabilityThe processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.

Processing and properties of Ti-15Zr-15Mo-(1-3)Ag alloys for applications as biofunctional materials

Titanium (Ti) is employed as a biomaterial because of its superior biocompatibility and favorable mechanical properties that can be changed with the addition of alloying elements, such as zirconium and molybdenum. Silver is an alloying element recognized for its antibacterial action, which can improve the mechanical strength and decrease Young’s modulus of Ti. This work studies the effect of silver addition (1 and 3 wt%) on the crystalline structure, microstructure, Vickers microhardness and Young’s modulus of Ti-15Zr-15Mo (wt%) alloy, targeting for a potential application as a biofunctional material. The ingots were produced by argon arc melting and subsequently subjected to a heat treatment of homogenization, hot-rolling and solubilization heat treatment. Chemical composition indicated good quality on the processing of the alloy. Crystalline structure and microstructure analyzed by X-ray diffraction, optical microscopy and scanning electron microscopy showed only titanium’s β phase. Finally, mechanical properties studied by Vickers microhardness and Young’s modulus measurements presented that the addition of low content of silver did not significantly modify the alloy’s mechanical properties, but it can include antibacterial properties on the bulk.

Effect of silver addition in copper-silver alloys fabricated by laser powder bed fusion in situ alloying

In this study copper-silver (CuAg) structures with varying Ag content were fabricated by in situ alloying and Laser Powder Bed Fusion (L-PBF) Additive Manufacturing (AM). Powder morphology, distribution and elemental analysis were conducted using Scanning Electron Microscopy (SEM) and dynamic imaging for CuAg10, CuAg20 and CuAg30 atomised powder. The resultant pore defect morphology and distribution for each as built and annealed CuAg alloy structure was investigated and reported using X-ray Computed Tomography (XCT) and 3D visualisation. The atomic crystal structure for each as built and annealed CuAg alloy is reported through X-Ray Diffraction (XRD) analysis. Yield strength, Young’s Modulus, failure strain and Ultimate Tensile Strength (UTS) of as built and annealed AM CuAg structures are reported and sample fracture surfaces were analysed using SEM and Energy Dispersive X-Ray (EDX) techniques. Increased Ag content from CuAg10% to CuAg30% is shown to decrease the number of pore defects by 87% and 83% for as built and annealed samples with average pore size decreasing by 40% and 9.5%. However, the annealing process was found to increase the porosity by up to 164%. Furthermore, the annealing process resulted in atomic lattice contractions resulting in increased yield strength, Youngs Modulus and Ultimate Tensile Strength (UTS) for CuAg30%.

The Influence of Ag on the Microstructure and Properties of Cu-Ni-Si Alloys.

The influence of the mass concentration of Ag on properties of Cu-Ni alloys is investigated. The effect of silver addition on the structure and properties of Cu-2Ni-1Si alloys is determined. The scientific aim of this research is to determine how the addition of silver affects the mechanisms of strengthening silver-modified supersaturated, deformed, and aged Cu-2Ni-1Si alloys. The applied thermo-derivative analysis has allowed us to determine a range of the temperature values for the beginning and the end of crystallization, the phases and eutectics, and the effects of the modification on the solid fraction of the solidified alloy. In addition to the crystallization kinetics, the microstructure morphology, mechanical properties under real operating conditions, and the electrical conductivity have also been investigated. Moreover, the conducted research includes the impact of heat treatment and plastic deformation on the alloy structure and considers the type, share, and distribution of the intermetallic phases and structural stresses caused by coherent phases, as well as the effect of dislocations in the reinforcing phases during aging. Electron microscopy (SEM), micro-area analysis (EDS), optical microscopy, hardness measurements, and conductivity of the tested alloys are utilized to comment on these properties.

Effect of Silver Addition on the Adsorption Properties of Y Zeolite

The present work is aim to study the adsorption/desorption properties of the Ag-modified Y zeolite towards toluene as well as its high temperature behavior under the prompt thermal aging conditions. The Ag/Y samples were obtained by an ion exchange technique and mixed with pure alumina used as a binder. The reference samples were prepared by an incipient wetness impregnation of alumina with a solution of silver nitrate and mixed with pure HY zeolite. The initial and aged samples were characterized by TEM and XRD methods. It was found that the Ag-modified Y zeolite strongly adsorbs toluene. Irreversible sorption of toluene over the most active silver sites was shown to exclude them from the participation in oxidation processes, thus diminishing the overall efficiency of the adsorption-catalytic system.

Effects of silver doping on magnetic levitation performance of MgB2 superconductors

MgB2 bulk samples with the silver contents of 0, 1.5, 3.0, 4.5, 6.0, 9.0 and 12.0 wt% were fabricated at 775 °C for 3 h in Ar atmosphere by solid-state reaction method. The structural and electromagnetic properties of MgB2 samples were studied using X-ray diffraction (XRD), scanning electronic microscope (SEM), energy dispersive spectrometry (EDS), magnetic hysteresis (M-H and M-T), magnetic levitation force (Fz) and lateral force (Fx) measurements. The effect of silver addition on the levitation force performance of MgB2 has been studied for the first time in this work. All the samples indicate the onset of superconducting critical temperature (Tc,onset) in the temperature range 37.97–38.11 K. The Jc values of the 3 wt% of silver doped MgB2 sample at 15 and 25 K were 98 and 49 kA/cm2 at 0.5 T as the highest remnant Jc value was around 110 and 65 kA/cm2 at 15 and 25 K, respectively. The repulsive and attractive levitation force at 25 K increases with rising x content up to 3 wt% silver and then decreases with increasing silver addition up to 12 wt%. The maximum attractive (repulsive) levitation force values at 25 and 30 K were observed for 3 wt% silver addition as −7.09 (+19.03) and −6.03 (+15.22), respectively. These results reveal that the silver addition is the effective metallic dopant for MgB2 and can be beneficial for improving the magnetic levitation achievement of MgB2 superconductors for high field engineering applications.

Selective laser melting of silver submicron powder modified 316L stainless steel: Influence of silver addition on microstructures and performances

In order to enhance electrical conductivity and corrosion resistance of 316L stainless steel for advanced applications, submicron silver powder was introduced into the 316L stainless steel matrix by the mean of selective laser melting. The effects of silver addition (5 wt%) on the resultant microstructures and associated physical performances of the SLMed Ag-modified composite were comprehensively investigated. Results revealed that silver addition led to the decrease of relative density and formation of finer sub-grains. Pure silver phase existed in the SLMed Ag-modified composite in the forms of micro-size silver aggregations (uniformly distributed among the 316L stainless steel matrix) and nano-size silver particles (interspersed along sub-grain boundaries). Improved electrical conductivity and corrosion resistance were obtained after the addition of silver. The influencing mechanism of modifying particles on microstructures and properties of SLM metallic composites, obtained in this work, could benefit the development of novel metallic composites towards new applications of multi-function.

Effect of Silver Addition on Mechanical Properties and Stress Corrosion Cracking in a Predeformed and Overaged 7055 Aluminum Alloy

Abstract The effect of silver on mechanical properties and stress corrosion cracking (SCC) resistance in a predeformed and overaged 7055 aluminum alloy was investigated. The treatment consisted of solution treating the specimens and then applying 5 % plastic deformation (compression) before aging. The next operation was aging the specimens at 121°C for 24 hours and overaging them at 175°C for 10 hours. Properties of the alloys were investigated by mechanical testing, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and differential scanning calorimetry. Results show that the ultimate tensile strength (UTS) and yield tensile strength (YTS) for the silver-free alloy were 580 and 520 MPa, respectively, and increased to 594 and 567 MPa after the addition of 0.39 % silver. Moreover, the stress corrosion resistance increased ≥ 23 % after adding 0.2 % silver. It can be seen that the addition of silver to predeformed and overaged 7055 aluminum alloy slightly improves the UTS and YTS and increases resistance to SCC significantly. These improvements are due to the interrupting effect of silver on the continuity of magnesium-rich precipitates and the increasing copper absorption in the precipitates.

Investigation of thermal and mechanical properties of Cu-Al alloys with silver addition prepared by powder metallurgy

In this study, Cu-10 wt.% Al-X wt.% Ag alloys (X = 0.0, 2.0, 2.5, 3.0, 4.0, 5.0, 5.5, 6.0) were synthesized through Powder Metallurgy. The effect of silver addition on microstructural, thermal and mechanical properties of the prepared alloys were investigated by using Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), X-rays Diffractometry (XRD), Transient Plane Source method (TPS), Rockwell hardness tester and Universal testing Machines. The XRD result of raw materials such as pure copper, pure aluminum, pure silver were qualified through JCPDS cards, and subsequently quantified. The microstructural analysis of all samples was carried out, with heating rate of 5 ̊C/min and annealed at room temperature. The results indicated that presence of silver in Cu-Al alloy offered better hardness up-to 3%Ag and compression strength increases up to 2%Ag in Cu-10 wt. %Al alloys which shows intermetallic structure in XRD analysis. Thermal conductivity and thermal diffusivity of the prepared alloys are investigated with help of TPS method in this work. It is observed that both thermal conductivity and thermal diffusivity increased with the increase of silver contents in the alloys owing to higher conductive behavior of silver.

Effect of Silver Addition on Transient and Steady State Creep Characteristics of Eutectic Sn-9Zn Binary Alloy

Effect of Silver Addition on Transient and Steady State Creep Characteristics of Eutectic Sn-9Zn Binary Alloy

The effect of silver addition on microstructure and thermal properties of the Cu–10%Al–8%Mn shape memory alloy

The influence of Ag addition on microstructure and thermal properties of the Cu-10%Al–8%Mn alloy was investigated in this work. Two alloys with designed compositions Cu-10%Al–8%Mn and Cu-10%Al–8%Mn-4%Ag (in wt.%) were prepared by induction melting of pure metals. Microstructures of the prepared samples were investigated in the as-cast state, after homogenization annealing and after quenching. The effects of different methods of heat treatment on the microstructure and transformation temperatures of the investigated Cu-10%Al–8%Mn and Cu-10%Al–8%Mn-4%Ag alloys were investigated using SEM-EDS and DSC techniques.It was determined that after induction melting microstructure of the both investigated alloys are primarily composed of martensite and a small amount of α-phase precipitates.Fully martensitic structure in both investigated alloys was obtained after direct quenching from the 850 °C into the ice water. Based on the DSC cooling curves it was determined that two-step martensite transformation for the both investigated alloys occur in the temperature interval from about 30 to -40 °C.

Synthesis and characteristics of sol-gel bioactive SiO2-P2O5-CaO-Ag2O glasses

In this research, the effects of silver additions on the properties of bioactive glass (BG) were investigated. The synthesis of SiO2–CaO–P2O5–Ag2O bioactive glass was performed by the sol-gel route. The synthesized compounds were treated in simulated body fluid (SBF) for 3, 7, and 14days to study the bioactivity of the new glass composition. The obtained samples were evaluated by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), inductively coupled plasma spectroscopy (ICP), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) analyses, MTT assay, and pH meter. Glass specimen with 2mol% of Ag2O exhibited a higher bioactivity when compared with samples containing 4mol% and 6mol% Ag2O. Finally, after 14days, the sample exhibited perfectly dispersed glacier shaped morphology of apatite. This type of morphology has not been previously reported.

Preparation and properties of antibacterial, biocompatible core–shell fibers produced by coaxial electrospinning

ABSTRACTCoaxial electrospinning is a method for producing fibrous mats with optional features, such as antibacterial properties, controllable release, and hydrophobicity based on shell materials. Because these features are important in biomedical applications, in this study, biocompatible hydrophobic polymer (polycaprolactone) and hydrophilic polymer [poly(vinyl alcohol)] with silver nanoparticles loaded in the core solution were coaxially electrospun. The effect of silver addition on the conductivity and viscosity of the solutions, chemical structure of the fiber mats, mechanical properties, porosity, hydrophobicity, water vapor transmission rate (WVTR), silver release, and antibacterial properties were investigated. Fibers with silver exhibited less porosity and a lower WVTR and a greater contact angle than the fibers without silver. Furthermore, the core–shell fibers reduced the burst release of silver and successfully prevented the growth of Escherichia coli and Staphylococcus aureus bacteria. Therefore, it seems that these fibers are suitable for providing electrospun mats with long‐term antibacterial properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44979.

Effect of silver additions on the structural properties and phase composition of TiO2/Ag composites

We have studied the effect of silver nitrate additions on the anatase–rutile transformation of titanium dioxide in TiO2/Ag composites at low temperature (500°C). The structure and phase composition of the composites with different Ag(I) concentrations have been determined by X-ray diffraction and transmission electron microscopy. The results demonstrate that the percentage of rutile increases with increasing Ag(I) ion concentration, reaching 60 wt %. A mechanism of the anatase–rutile transformation in the composites has been proposed.

Possible Enhancement of Spin Fluctuations by Ag addition to SmFeAsO1−x F x

We investigate the effect of silver addition to polycrystalline SmFeAsO 1−xFx(Sm-1111) superconductor. Transport and magnetic measurement data reveal the enhancement of the magnetic fluctuation with increasing silver content.