Effect Of Ag Addition Research Articles

Effect of Ag addition on the mechanical properties of Cu/Ni/Sn/Ni/Cu microbump with a sub-10 micron bump thickness

Effect of Ag addition on the mechanical properties of Cu/Ni/Sn/Ni/Cu microbump with a sub-10 micron bump thickness

Role of Ag Addition on the Microscopic Material Properties of (Ag,Cu)(In,Ga)Se2 Absorbers and Their Effects on Losses in the Open‐Circuit Voltage of Corresponding Devices

ABSTRACTAg alloying of Cu(In,Ga)Se2 (CIGSe) absorbers in thin‐film solar cells leads to improved crystallization of these absorber layers at lower substrate temperatures than for Ag‐free CIGSe thin films as well as to enhanced cation interdiffusion, resulting in reduced Ga/In gradients. However, the role of Ag in the microscopic structure–property relationships in the (Ag,Cu)(In,Ga)Se2 thin‐film solar cells as well as a correlation between the various microscopic properties of the polycrystalline ACIGSe absorber and open‐circuit voltage of the corresponding solar cell device has not been reported earlier. In the present work, we study the effect of Ag addition by analyzing the differences in the various bulk, grain‐boundary, optoelectronic, emission, and absorption‐edge properties of ACIGSe absorbers with that of a reference CIGSe absorber. By comparing thin‐film solar cells with similar band‐gap energies ranging from about 1.1 to about 1.2 eV, we were able to correlate the differences in their absorber material properties with the differences in the device performance of the corresponding solar cells. Various microscopic origins of open‐circuit voltage losses were identified, such as strong Ga/In gradients and local compositional variations within individual grains of ACIGSe layers, which are linked to absorption‐edge broadening, lateral fluctuations in luminescence‐energy distribution, and band tailing, thus contributing to radiative VOC losses. A correlation established between the effective electron lifetime, average grain size, and lifetime at the grain boundaries indicates that enhanced nonradiative recombination at grain boundaries is a major contributor to the overall VOC deficit in ACIGSe solar cells. Although the alloying with Ag has been effective in increasing the grain size and the effective electron lifetime, still, the Ga/In gradients and the grain‐boundary recombination in the ACIGSe absorbers must be reduced further to improve the solar‐cell performance.

Effect of Ag Addition to Au Catalysts for the Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid

AbstractThe addition of Ag to Au nanocatalysts is known to improve several catalytic reduction and oxidation reactions. Until now, bimetallic AuAg catalysts have not been studied in detail in liquid phase oxidation reactions. We investigated the activity, selectivity, and stability of silica supported Au, Ag and AuAg catalysts in the oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), an important reaction to produce bio‐based polymers. We demonstrate that addition of an optimum amount of inactive Ag to the active Au catalyst substantially increases the overall selectivity and yield of the desired FDCA. Interestingly, Ag addition decreased the conversion rate of the reactant HMF to the intermediate HMFCA, but improved (up to 10–20 % Ag addition) much the conversion of the intermediate product to the desired final product. This is probably due to tuning the electronic properties of the nanoparticles to achieve an optimum adsorption strength of the intermediate on the surface of AuAg catalysts. Moreover, particle growth was suppressed by the bimetallic AuAg catalyst, ultimately leading to superior stability compared to its monometallic counterparts.

Effect of Ag addition on high-temperature self-lubricating behavior of CuNi-based composites

CuNi-based high-temperature self-lubricating composites with BaF2/CaF2 eutectic as a main lubricant were prepared by rapid hot-pressing. The results showed that the addition of BaF2/CaF2 can introduce heterogeneous structures, in which the hard phase of BaF2/CaF2 closely surrounded the soft copper alloy phase. The high strength of the composite was mainly derived from the dislocation strengthening caused by the heterogeneous deformation induced stress, and solid solution strengthening induced by Ag. At 500 ℃, the excellent tribological performance was mainly attributed to the combined lubricating effects of Ag, BaF2/CaF2 and metal oxides. Furthermore, the addition of Ag formed concrete and continuous lubricating film on the worn surface, with more fluorides to continuously and stably protect the composite substrate.

Effect of Ag-addition on the thermoelectric properties of Cu12Sb4S13 tetrahedrite

Tetrahedrite, Cu12Sb4S13, an eco-friendly thermoelectric material with earth-abundant and low-cost constituents, has garnered global interest. This study investigated the thermoelectric characteristics of Ag-added tetrahedrites, which were prepared through solid-state synthesis and subsequently hot-pressed. The minimal temperature dependence of the transport coefficient indicated the presence of strong electron–phonon coupling in the samples. It was observed that Ag addition in tetrahedrite could successfully scatter acoustic phonons, reducing the lattice thermal conductivity while minimally affecting the power factor. The enhanced anharmonicity induced by Ag addition is the primary cause of reduced lattice thermal conductivity. Raman spectroscopy data showed that Ag addition could weaken the Sb–S bond, further supporting the previous argument. Consequently, the lattice thermal conductivity was lowered to ∼0.27 W m−1 K−1 and obtained for the composition Ag0.025 added Cu11.975Sb4S13. A relatively high power factor of ∼1.3 mW m−1 K−2 was obtained for the same composition. Owing to the lowest total thermal conductivity ∼1.09 W m−1 K−1, the sample with composition Ag0.025 added Cu11.975Sb4S13 showed the highest thermoelectric figure of merit of 0.87 at 738 K.

Disclosing the formation mechanisms of Ag-containing Laves phases at the atomic scale in an Al-Cu-Mg-Ag alloy

In addition to the three well-known Ag-related precipitates (Ω, X′ and Z) in the Al-Cu-Mg-Ag alloys, Ag can also be involved in the formation of the as-cast second phases. However, the effect of Ag addition in Al-Cu-Mg-Ag alloys has not been completely studied and even the structure of the as-cast Ag-containing phases is still controversial. By employing the focused ion beam (FIB) combined with transmission electron microscopy (TEM) techniques and density functional theory (DFT) calculations, the formation mechanisms of the Ag-containing phases in the as-cast Al-Cu-Mg-Ag alloys have been investigated. The Ag-containing phases are a series of hexagonal C14-type Laves phases with continuously varying Ag concentrations, described as (AlxCuyAg1-x-y)2Mg. Moreover, the specific occupancy sites of the atoms in (AlxCuyAg1-x-y)2Mg were determined. The formation of the (AlxCuyAg1-x-y)2Mg can be attributed to the stronger Ag-induced aggregation of solute atoms in the initial stage and the establishment of strong Ag-X (X = Al, Mg and Ag) bonding in the Ag-containing phases. Furthermore, our experiments have revealed the solidification sequence of Al-Cu-Mg-Ag alloys, and pointed out that (AlxCuyAg1-x-y)2Mg is formed at a lower temperature (493.9 °C) through the reaction L ⇌ Al2CuMg + (AlxCuyAg1-x-y)2Mg. The study could have positive implications for refinement of the Al-Cu-Mg-Ag quaternary phase diagram and promote the composition-property design of novel aluminum alloys based on (AlxCuyAg1-x-y)2Mg in the future.

Effect of Ag addition on the microstructure and corrosion properties of Sn–9Zn lead-free solder

The effects of Ag addition on the microstructure of Sn–9Zn alloy and its corrosion behaviour in neutral and static 3.5 wt% NaCl solutions were investigated using surface characterization techniques and electrochemical techniques. The results show that in Sn–9Zn-xAg alloys, Ag reacts with Zn to form AgZn3 intermetallic compounds (IMCs), which refined the microstructure of the alloys and changed the corrosion mode of the alloy surfaces from pitting corrosion to surface corrosion. The addition of Ag effectively improved the corrosion passivation film structure and electron transfer characteristics of the alloy, increased the self-corrosion potential (Ecorr) and reduced the self-corrosion current (Icorr), thus improving the corrosion resistance of the alloy. The study explained and verified the corrosion mechanism of the alloy from both experimental and theoretical perspectives. It is concluded that Sn–9Zn-0.4Ag alloy shows relatively the best corrosion resistance.

Revisiting the effect of Ag additions on Ω precipitation and heat resistance of Al–Cu–Mg–Si–Ag alloys

In heat-resistant Al–Cu–Mg–Ag alloys, the presence of AgMg segregation layer on Ω phase ensures its high thermal stability. It was reported Ω precipitation would be inhibited when Si was added such that the Mg/Si mass ratio was lower than 2. However, in this work, it has been proved the notable increase in Ag content from 0.5% to 0.8% could still promote precipitation of Ω besides θ′ in an Al–Cu–Mg–Ag–Si alloy with a Mg/Si mass ratio around 1.7. The key point is to obtain an Ag/Mgexcess atomic ratio greater than 1 under the premise of W(Mg)/W(Si) > 1.4 in the supersaturated solid solution, where Mgexcess denotes the remaining Mg solutes after the formation of C/L phase. Although the fine precipitation of Ω in the 0.8 Ag alloy increases the total volume fraction of precipitates and yield strength, their quick coarsening at high temperature leads to a more pronounced strength loss. Such a comparison reveals the fully enveloped Ω precipitate is less stable than the θ′ precipitate with multiple interface phases. These findings update our knowledge on the systematic composition design for tunning Ω/θ′ precipitates' ratio and properties of Al–Cu–Mg–Ag–Si alloys.

Minor Ag inducedshear performance alternation in BGA structure Cu/SnBi/Cu solder joints under electric current stressing

In this work, the effect of minor Ag addition on shear performance of ball grid array (BGA) structure Cu/SnBi/Cu solder joints under electric current stressing was investigated. The results show that the shear strength of solder joints decreased with increasing current density, and the effect of Ag addition on shear strength changed from an elevating state to a deteriorating state. The elevating effect of Ag addition was due to the dominance of Sn/Bi phase refinement and Ag3Sn dispersion, which was weakened gradually with the increase in current density. The deteriorating effect of Ag addition was attributed to the more inhomogeneous distribution of current density and higher thermal gradient induced by the finer phase of the solder matrix as well as the consequent severer strain mismatch at the Sn/Bi phase interface. The finer Sn/Bi phase was also conductive to easier lattice atom migration under current stressing, resulting in a rapid decrease in shear strength. Moreover, the dominant factor on the shear strength reduction tended to change from Joule heating to athermal effect of current stressing. The fracture of solder joints indicated an insignificant influence by the Ag addition, which all occurred in the solder matrix in a ductile mode.

Effect of Ag addition on the oxidation behavior of CrAlN coating at elevated temperatures

The effect of oxidation temperature and amount of Ag addition on CrAlN coating was investigated in this study. No Ag and Ag-based CrAlN coatings were deposited on a substrate using a physical vapor deposition (PVD) technique. The coatings then were isothermally heated at 800 °C and 900 °C for the 2 hr. Interestingly it is found that even with a small difference in temperature (100 °C), CrAlNAg coating shows different nature of oxidation, mass gain curve, coating microstructure and surface morphology.Surface morphology revels the Ag clusters formation on the top associated with the high temperature heating. While cross-section morphology gives information about Ag distribution and oxides layer formation. Mass gain curve and EDS (Energy-dispersive X-ray spectroscopy) results revealed that the oxidation resistant behavior of the CrAlN coating was degrade with increasing Ag content and/or increasing oxidation temperature. Overall, the results suggest that the temperature has a significant effect on the microstructure and properties of Ag-based coatings, and optimizing the deposition temperature can improve the performance of these coatings in various applications.

Effects of microalloying with Ag, Li, and Sc on hot-deformed microstructure of Al–Mg–Si–Cu alloys

The effects of microalloying with Ag, Li, and Sc on the hot-extruded microstructures of Al–Mg–Si–Cu alloys were studied. Each microalloying element was observed to affect the hot-deformed microstructure of the alloy, with a retarding effect on its recrystallization; however, the effect of Ag-addition was relatively small. The number fraction of grains with a high Taylor factor and their kernel average misorientation significantly increased when Li and Sc were added to the Al–Mg–Si–Cu alloy, implying a strong anisotropy of slip. It was also found that Li-addition primarily weakened the C component, whereas Sc-addition significantly strengthened the rotated copper (Rt-Cu) component in the deformation texture, and strongly dissipated the recrystallization texture. Additionally, all the microalloying elements slightly increased the dislocation density and fraction of edge dislocations. Thus, a very close dislocation arrangement with a strong screening of dislocations was observed; however, this effect was relatively weak for the Sc-added alloy. The high variation in the microstructural parameters of the Sc-added alloy was understood to depend primarily on the Al3Sc dispersoid and its effect on the other precipitates. In contrast, Ag- and Li- additions did not significantly change the relatively large precipitate structure, which implies that there were changes in the nanoscale precipitates or solute clustering during the hot deformation of Ag- and Li-added alloys.

Quantitative evaluation of the effect of Ag-addition on the concurrently-existing precipitation kinetics in the aged Al-Cu-Mg(-Ag) alloys

Two Al-Cu-Mg(-Ag) aluminium alloys, having the same base composition of Al-5.11Cu-0.96 Mg-0.58Mn-0.12Zr (wt.%) but different Ag contents, 0 and 0.7 Ag (wt.%), and accordingly denoted 0A and 7A samples, were aged at 185 °C. In early-ageing, the formation of disk-like Mg-Cu and Mg-Ag nano(co–)clusters can be quantitatively examined by Small angle X-ray scattering (SAXS), respectively. In the prolonged ageing of the 0A samples, the thickening in the disk-like θ-precipitates leads to a lower aspect ratio. For S-precipitates, the change in the total surface area and the single-particle surface area indicates that the coalescence mechanism is prevalent from peak-ageing to over-ageing, and then after over-ageing, the precipitate coarsening dominates. The coarsening in S and θ precipitates presumably leads to a lower mechanical strength. Alternatively, in the aged 7A sample, the SAXS technique in conjunction with transmission electron microscopy (TEM) quantitatively reveals Ω-precipitates possessing a nearly constant thickness but an increase in diameter with ageing time. Additionally, the stable behaviors of the total surface and size of S-precipitates illuminate that the coalescence/coarsening mechanisms are significantly slowed down. The concurrently-existing precipitation kinetics of Ω and S have provided an in-depth understanding of the higher strength of the aged 7A sample.

Study on the effects of Ag addition on the mechanical properties and oxidation resistance of Sn–Zn lead-free solder alloy by high-throughput method

Study on the effects of Ag addition on the mechanical properties and oxidation resistance of Sn–Zn lead-free solder alloy by high-throughput method

Effect of Ag addition on the characteristics of precipitates and improving age hardening response of Mg 6Bi alloy

The effect of Ag addition on the characteristics of precipitates and age hardening response of Mg 6Bi alloy were investigated. The results illustrate that the Ag addition in Mg Bi alloy can significantly enhance the age hardening response of the alloy. The peak-aged hardness increases from 51.8 HV of the Mg 6Bi alloy to 59.1 HV of the Mg-Bi-Ag alloy after ageing at 160 °C for 40 h, which is increased by 14.1%. Using high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) and STEM-EDS (energy dispersive X-ray spectroscopy), the crystal orientation relationships (ORs) between the Mg 3 Bi 2 precipitate and Mg matrix were characterized to be [0001] Mg3Bi2 //[1 1 2 ¯ 0] Mg , (1 1 ¯ 0 0) Mg3Bi2 //(1 1 ¯ 0 0) Mg , (1 1 2 ¯ 0) Mg3Bi2 //(0001) Mg , and [1 1 2 ¯ 0] Mg3Bi2 //[1 1 2 ¯ 0] Mg , (0 0 0 1) Mg3Bi2 //(1 1 ¯ 0 2 ¯ ) Mg , (1 1 ¯ 0 2) Mg3Bi2 //(0 0 0 1 ¯ ) Mg . Furthermore, it was found that Ag atoms can be not only enriched in the Mg 3 Bi 2 precipitates but also segregated at the interface between the Mg 3 Bi 2 precipitate and Mg matrix. Thus, it promotes the nucleation rate and slows down the growth of the precipitates, resulting in the fined precipitates and the increased number density of precipitates. The roles of Ag in the improving ageing hardening response and characteristic of precipitates are discussed in the present paper. • Microstructure and age hardening response of Mg-Bi-Ag alloy were investigated. • The age hardening response of Mg Bi is significantly enhanced by Ag addition. • Ag addition refines the Mg 3 Bi 2 precipitate and increases its number density. • Ag atoms are both enriched within Mg 3 Bi 2 phase and segregated at the interface.

Effect of Ag Addition on Microstructure, Mechanical and Corrosion Properties of Mg–Nd–Zn–Zr Alloy for Orthopedic Application

Effect of Ag Addition on Microstructure, Mechanical and Corrosion Properties of Mg–Nd–Zn–Zr Alloy for Orthopedic Application

Oxidation of Toluene by Ozone over Surface-Modified γ-Al2O3: Effect of Ag Addition

In this study, the ability of ozone to oxidise toluene present in low levels into CO and CO2 was studied. The catalytic ozonation of toluene was carried out in a micro-fixed bed reactor. The oxidation was done in two steps: toluene adsorption on the catalyst followed by sequential ozone desorption. Toluene breakdown by ozone at low temperature and atmospheric pressure was achieved using γ-Al2O3 supported transition metal oxides impregnated with a reduced noble metal. The catalyst Ag–CoOx/γ-Al2O3 efficiently oxidised and transformed toluene into products (52.4% COx yield). This catalyst has a high surface area, more acidic sites, and lattice oxygens for better toluene oxidation. The addition of Ag to the CoOx/γ-Al2O3 catalyst surface improved toluene adsorption on the catalyst surface, resulting in improved product yield, selectivity, and carbon balance.

Effects of Ag Addition on the Microstructure and Elevated Temperature Mechanical Properties of as-cast Mg-6Gd-2Y-Nd-xAg-0.4Zn-0.5Zr Alloys

Effects of Ag Addition on the Microstructure and Elevated Temperature Mechanical Properties of as-cast Mg-6Gd-2Y-Nd-xAg-0.4Zn-0.5Zr Alloys

Effects of Ag addition and dendritic scale on the corrosion behavior of the hypoeutectic Al-5wt% Si alloy

Effects of Ag addition and dendritic scale on the corrosion behavior of the hypoeutectic Al-5wt% Si alloy

Effect of Ag addition on the microstructure and electrical properties of Ni0.6CoMn1.4O4/Ag composite ceramics

In this work, novel Ni0.6CoMn1.4O4: x wt%Ag (NCMO: Ag-x, x = 0, 5, 7.5, 10, 12.5, and 15) composite ceramics were successfully fabricated by combining chemical reduction with solid-state coordination reaction method. The phase composition, microstructure, element distribution, and electrical properties are systematically investigated. The introduced Ag nanoparticles formed heterogeneous interfaces with the NCMO particles and were uniformly distributed in the samples. Due to the introduction of Ag, the Co2+ content increases from 33.2% to 50.0%. The average valence state of Mn ions increases from 2.91 to 3.17, then it decreases to 2.89. The Ag addition does facilitate the remarkable reduction of room temperature resistivity from 250.38 to 7.61 Ω cm and makes the resistivity drift below 2.57%, while B value decreases from 3145 to 1909 K, which are caused by the decreases of grain resistance and grain boundary resistance. Moreover, space electronic transmission mechanism is also proposed to further explain the positive effect of Ag introduction on electrical properties of the NCMO/Ag composite ceramics.

Effect of Ag addition into the Activity of Titanium Silicate-1 Catalyst in Cyclohexanone Reaction

Titanium Silicate-1 (TS-1) has been successfully modified by combining Silver (Ag) metals. In this study, the preparation of Ag/TS-1 was carried out by impregnation method using a solution of silver nitrate (AgNO3) as a precursor to TS-1 with a loading variation of 0.5%, 1%, 2%, and 4%. Impregnation carried out on TS-1 aims to disperse Ag (1) only attached to the surface of TS-1 particles (before calcination/TK) and (2) on the entire surface of TS-1 particles (after calcination/K). The synthesized catalyst was then characterized by X-ray diffraction, infrared spectroscopy, and pyridine adsorption techniques. The XRD pattern shows that all the catalysts have high crystallinity with MFI structure, and there is no other crystalline phase. The infrared spectra showed that the titanium tetrahedral in TS-1 remained after Ag impregnation. The TS-1 and Ag/TS-1 catalysts were analyzed for their surface acidity using pyridine adsorption on the sample. The pyridine adsorption technique showed the presence of Lewis sites on Ag/TS-1. In this study, the presence of Ag loading on the Ag/TS-1 catalyst affected the TS-1 catalytic activity. The amount of cyclohexanone oxime product produced in XAg/TS-1 was more than in Ag/TS-1.