Ag-based Alloys Research Articles

Nature of the Active Center for the Oxygen Reduction on Ag-Based Single-Atom Alloy Clusters.

The development of alternative alloy catalysts with high activity, surpassing platinum group metals, for the oxygen reduction reaction (ORR) is urgently needed in the field of electrocatalysis. The Ag-based single-atom alloy (AgSAA) cluster has been proposed as a promising catalyst for the ORR; however, enhancing its activity under operational conditions remains challenging due to limited insights into its actual active site. Here, we demonstrate that the operando formation of the MO x (OH) y complex serves as the key active site for catalyzing the ORR over AgSAA cluster catalysts, as revealed through comprehensive neural network potential molecular dynamics simulations combined with first-principles calculations. The volcano plot of the ORR over the MO x (OH) y complex addresses the gaps inherent in traditional metallic alloy models for pure AgSAA cluster catalysts in ORR catalysis. The appropriate orbital hybridization between OH and the dopant metal in the MO x (OH) y complexes indicated that the Ag54Co1, Ag54Pd1, and Ag54Au1 clusters are optimal AgSAA catalysts for the ORR. Our work underscores the significance of theoretical modeling considering the reaction atmosphere in uncovering the true active site for the ORR, which can be extended to other reaction systems for rational catalyst design.

Rationally Designed Li-Ag Alloy with In-Situ-Formed Solid Electrolyte Interphase for All-Solid-State Lithium Batteries.

All-solid-state lithium batteries (ASSLBs) with sulfide-based solid electrolytes have attracted significant attention as promising energy storage devices, owing to their high energy density and enhanced safety. However, the combination of a lithium metal anode and a sulfide solid electrolyte results in performance degradation, owing to lithium dendrite growth and the side reactions of lithium metal with the solid electrolyte. To address these issues, a Ag-based Li alloy with a favorable solid electrolyte interphase (SEI) was prepared using electrodeposition and applied to the ASSLB as an anode. The electrochemically formed SEI layer on the Li-Ag alloy primarily comprised LiF and Li2O with high mechanical strength and Li3N with high ionic conductivity, which suppressed the formation of lithium dendrites and short-circuiting of the cell. The symmetric cell with the Li-Ag alloy achieved a critical current density of 1.6 mA cm-2 and maintained stable cycling for over 2000 h at a current density of 0.6 mA cm-2. Consequently, the all-solid-state lithium cell assembled with the Li-Ag alloy anode with SEI, Li6PS5Cl solid electrolyte, and LiNi0.78Co0.10Mn0.12O2 cathode delivered a high discharge capacity of 185 mAh g-1 and exhibited good cycling performance in terms of cycling stability and rate capability at 25 °C.

Early Stages of Metal Corrosion in Coastal Archaeological Sites: Effects of Chemical Composition in Silver and Copper Alloys.

In this study, metal disks with different chemical composition (two Ag-based alloys and three Cu-based alloys) were buried in the soil of coastal archaeological sites for a period of 15 years. The aim was to naturally induce the growth of corrosion patinas to obtain a deeper insight into the role of alloying elements in the formation of the patinas and into the degradation mechanisms occurring in the very early stages of burial. To reach the aim, the morphological, compositional and structural features of the patinas grown over 15 years were extensively characterized by optical microscopy, field emission scanning electron microscopy coupled with energy dispersive spectrometry, X-ray diffraction and micro-Raman spectroscopy. Results showed that the Cu amount in Ag-based alloys strongly affected the final appearance, as well as the composition and structure of the patinas. Corrosion mechanisms typical of archaeological finds, such as the selective dissolution of Cu, Pb and Zn and internal oxidation of Sn, occurred in the Cu-based alloys, even if areas enriched in Zn and Pb compounds were also detected and attributed to an early stage of degradation. In addition, some unusual and rare compounds were detected in the patinas developed on the Cu-based disks.

Impact of alloying elements on generalized stacking fault energy and twinning of Ag-based alloys

The creep strength of Ag-based alloys can be remarkably enhanced through the formation of twin structures. In this study, the effects of alloying elements, including Sn, In, Zn, Cu, Zr, Ni, Ir, Cr, and W, on the formation enthalpy of point defects and the generalized stacking fault energy of Ag-based alloys were investigated using first-principles calculations. The formation enthalpy of point defects serves as a measure of the difficulty of alloying element doping in Ag-based alloys. Calculation results shows that the ability of alloying element doping to form point defects follows the order of Sn > In > Zn > Cu > Zr > Ni > Ir > Cr > W. The generalized stacking fault energy along the [112‾](111) slip direction in Ag-based alloys characterizes the competition between dislocation slip and twinning. As the formation enthalpy of point defects increases, the intrinsic stacking fault energy increases, leading to a decrease in twinning tendency. Once the formation enthalpy of point defects corresponding to the alloying element exceeds 1 eV, the intrinsic stacking fault energy and twinning tendency remain relatively unchanged. Comprehensive analysis shows that alloying elements Sn and In effectively reduce the intrinsic stacking fault energy and promote twinning, which aligns with the behavior observed in commonly used Ag–Sn–In electrical contact materials.

Design and Synthesis of Ag-based Catalysts for Electrochemical CO2 Reduction: Advances and Perspectives.

Ag-based nanocrystals have emerged as an important candidate for CO2 reduction reaction (CO2 RR) owing to the increasing amount of CO2 in the atmosphere, which has shown a propensity to alleviate environmental problems and produce high value-added chemicals. This paper reviews the surface and interface engineering of Ag-based catalysts towards CO2 RR, which involve in the morphology control, composition manipulation, and support effects. Various synthesis approaches are presented to discuss their influence on the size, crystal structure and morphology of Ag-based catalysts, including pure Ag NPs, Ag-based alloys, Ag/metal oxides composites as well as Ag/carbon materials. Next, the development of Ag-based surface and interface engineering that is essential to accelerate the formation of CO and its further conversion to C1 or even multicarbon products is systematically discussed. Finally, we give a short conclusion, and perspectives on the rational design of Ag-based catalysts based on surface and interface engineering will be discussed.

Three new Ag-based full-Heusler alloys: Ag2TiGa, Ag2VGa, and Ag2TiTl

There are various new structures with superior performance for Heusler alloy materials that are widely used in spintronic materials, thermoelectric materials, and other fields. In this study, three new Ag-based full-Heusler alloys (Ag2TiGa, Ag2VGa, and Ag2TiTl) are proposed. The stability, mechanical properties, and electronic properties of these three new Ag-based Heusler alloys were studied using first-principles calculations. The results showed that the compression resistance, shear resistance, stiffness, and elastic anisotropy of Ag2VGa were greater than those of Ag2TiGa and Ag2TiTl, whereas the ductility of Ag2TiGa and Ag2TiTl was better than that of Ag2VGa. The spin density of states of Ag2VGa has evident spin splitting near the Fermi level, and the total magnetic moment of the Ag2VGa structure is 2.28 µB, which indicates that Ag2VGa is magnetic. These studies enrich research on Ag-based Heusler alloys and provide theoretical references for subsequent theoretical and experimental research.

Zirconia-high entropy alloys joints for biomedical applications: The role of Ag-based fillers on interfacial reactivity

Metal-ceramic joints represent an important choice for biomedical devices, in orthopaedic field or as micro-stimulators. ZrO 2 -Ag-HEA joint is here proposed to replace the currently used Ti6Al4V by new Ti-based refractory HEAs. To evaluate the system reactivity, wettability of ZrO 2 by different Ag-based alloys at 1000 °C and their interfacial layers were studied, for the first time. Interpretation and discussion of systems reactivity were supported by thermodynamic calculations, according to the CALPHAD approach and the ad-hoc Ag-Ti-Zr-O thermodynamic database, implemented in this work. A good wettability was reached at 1000 °C adding Ti to Ag: Ag-4Ti and Ag-8Ti reached contact angles of 81–85°. Ag-4Ti-2Zr showed the best wettability (77°) and the most complex interfacial microstructure. A continuous hcp (Ti,O), ~ 20 µm thick, promoted the wettability of Ag-4Ti and Ag-8Ti. In both cases, AgTi was the only intermetallic compound found in the bulk. Ag-4Ti-2Zr formed a thicker interfacial layer of hcp-(Ti,Zr,O) + bcc-(Ti,Zr) + a less compact Ag(Ti,Zr) 2 layer. Here, a low amount of Ag(Ti,Zr) and Ag(Ti,Zr) 2 was found in the Ag matrix. Since Ag resulted a promising filler to braze Ti-rich substrates to ZrO 2 at 1000 °C, preliminary HEA-Ag-ZrO 2 joints were characterized. A sound and defects-free interface was observed, with a first layer, mainly formed by Ag, Ti and Zr (HV ~ 600), and a Ag-based interface (HV ~ 250), extending until the HEA. Further works envisage mechanical and electrochemical evaluations of the system to pave the way for the production of novel HEA-Ag-ZrO 2 joints to be used in biomedical applications. • Ti addition to Ag promoted ZrO 2 wettability at 1000 °C forming hcp-(Ti,O) at the interface. • Ag-4Ti-2Zr tested on ZrO 2 at 1000 °C showed the best wettability (ϑ<80°). • An ad-hoc Ag-O-Ti-Zr database was assembled and used to support reactivity discussion. • Ag-4Ti-2Zr showed an hcp-(Ti,O)+bcc-(Ti,Zr)+Ag(Ti,Zr) 2 interfacial layer formed at 1000 °C. • Ti 1.5 ZrTa 0.5 Hf 0.5 Nb 0.5 HEA was successfully brazed to ZrO 2 by using a Ag filler at 1000 °C.

Improved biocompatibility of Zn–Ag-based stent materials by microstructure refinement

The metallurgical engineering of bioresorbable zinc (Zn)-based medical alloys would greatly benefit from clarification of the relationships between material properties and biological responses. Here we investigate the biocompatibility of three Zn-based silver (Ag)-containing alloys, ranging from binary to quinary alloy systems. Selected binary and quinary Zn–Ag-based alloys underwent solution treatment (ST) to increase the solubility of Ag-rich phases within the Zn bulk matrix, yielding two different microstructures (one without ST and a different one with ST) with the same elemental composition. This experimental design was intended to clarify the relationship between elemental profile/microstructure and biocompatibility for the Zn–Ag system. We found that the quinary alloy system (Zn–4Ag–0.8Cu–0.6Mn–0.15Zr) performed significantly better, in terms of histomorphometry, than any alloy system we have evaluated to date. Furthermore, when solution treated to increase strength and ductility and reduce the fraction of Ag-rich phases, the quinary alloy's biocompatibility further improved. In vitro corrosion testing and metallographic analysis of in vivo implants demonstrated a more uniform mode of corrosion for the solution treated alloy. We conclude that Zn–Ag alloys can be engineered through alloying to substantially reduce neointimal growth. The positive effect on neointimal growth can be further enhanced by dissolving the AgZn3 precipitates in the Zn matrix to improve the corrosion uniformity. These findings demonstrate that neointimal-forming cells can be regulated by elemental additions and microstructural changes in degradable Zn-based implant materials. Statement of significanceThe metallurgical engineering of bioresorbable zinc (Zn)-based medical alloys would greatly benefit from clarification of the relationships between material properties and biological responses. Here, selected binary and quinary Zn–Ag-based alloys underwent solution treatment (ST) to increase the solubility of Ag-rich phases within the Zn bulk matrix, yielding two different microstructures (one without ST and a different one with ST) with the same elemental composition. We found that applying a thermal treatment restores mechanical strength and mitigates the strain rate sensitivity of Zn–Ag alloys by dissolving AgZn3 precipitates. Ag-rich nano-precipitates in Zn decrease biocompatibility, a phenomenon that can be counteracted by dissolving the AgZn3 precipitates in the bulk Zn matrix.

Interdiffusion coefficient and atomic mobility for fcc Ag-Cu-Mg phase at 1073 K

In this work, the interdiffusion coefficient and atomic mobility for the fcc Ag-Cu-Mg phase at 1073 K were investigated by combining diffusion couple experiments and calculations. Based on the experimental composition profiles, the diffusion coefficients at the intersections of the diffusion paths were calculated using the Matano-Kirkaldy method. Using the thermodynamic descriptions available in the literature, the atomic mobilities for the fcc Ag-Cu-Mg phase were automatically optimized by numerical inverse method integrated with the CALTPP (CALculation of ThermoPhysical Properties) program. Moreover, the obtained atomic mobilities were confirmed to be reliable by good agreements between the model-simulated and the measured composition profiles. In addition, three-dimensional surfaces were presented for the interdiffusion coefficient, activation energy, and frequency factor. The presently obtained atomic mobilities can be incorporated into the diffusion database for Ag-based alloys, which can contribute to microstructure simulation and materials design.

Corrosion behavior of Ag-based alloy in simulated body fluid solution

Ag-based alloys are vital for joining bioceramics for implantable devices. However, rare research has conducted systematic studies on the biocompatibility of Ag-based alloys. Herein, the corrosion behaviors of two kinds of Ag-based alloys (AgCuTi and AgCu) in simulated body fluid are analyzed in detail through systematic electrochemical measurements. The corrosion resistance of these two alloys shows first increasing and then decreasing tendency with increasing corrosion time. The corrosion process of the AgCu alloy clearly shows the dissolution and deposition phenomenon, while the corrosion reaction of AgCuTi alloy is derived by deposition process. Further, during the corrosion process, AgCuTi alloy leaches less Cu and can produce some calcium phosphate. This study provides some instructional views on reliable joining of biomaterials.

Microstructure and Mechanical Properties of WC-Co/WC-Co Oxyacetylene Brazed Joints Using Ag-Based Filler Alloy

Microstructure and Mechanical Properties of WC-Co/WC-Co Oxyacetylene Brazed Joints Using Ag-Based Filler Alloy

Zinc alloy-based bone internal fixation screw with antibacterial and anti-osteolytic properties

There is no targeted effective treatment for patients undergoing internal fixation surgery/two-stage total joint revision surgery with a high risk of postoperative infection and osteolysis, while the rate of reoperation due to infection and osteolysis remains high. In this study, we report a pioneering application of implants made of biodegradable Zn–Ag alloy with active antibacterial and anti-osteolytic properties in three classical animal models, illustrating antibacterial, anti-osteolysis, and internal fixation for fractures. The antibacterial activity of the Zn–2Ag alloy was verified in a rat femur osteomyelitis prevention model, while the anti-osteolytic properties were evaluated using a mouse cranial osteolysis model. Moreover, the Zn–2Ag based screws showed similar performance in bone fracture fixation compared to the Ti–6Al–4V counterpart. The fracture healed completely after 3 months in the rabbit femoral condyle fracture model. Furthermore, the underlying antibacterial mechanism may include inhibition of biofilm formation, autolysis-related pathways, and antibiotic resistance pathways. Osseointegration mechanisms may include inhibition of osteoclast-associated protein expression, no effect on osteogenic protein expression, and no activation of related inflammatory protein expression. The empirical findings here reveal the great potential of Zn–Ag-based alloys for degradable biomaterials in internal fixation surgery/two-stage total joint revision surgery for patients with a high risk of postoperative infection and osteolysis.

Revealing the tensile anisotropy, tension–compression asymmetry, and strain-hardening behavior of a high-performance Mg–Gd–Ag alloy

Abstract Mg–Gd–Ag-based alloys have attracted considerable attention in recent years owing to their high strength. However, their characteristic mechanical behavior remains unclear. Herein, the tensile anisotropy, tension–compression asymmetry, and strain-hardening behavior of a high-performance Mg–10.6Gd–2Ag (wt%) alloy fabricated by equal-channel angular pressing (ECAP) were systematically investigated and correlated with the evolution of microstructure and texture. The ECAP alloy exhibited synchronously enhanced tensile strength and ductility along all three directions compared with the as-cast alloy as well as improved compressive strength along the extrusion direction (ED) accompanied by slightly decreased ductility. In contrast to the pronounced reversed yield asymmetry for the as-cast alloy, the ECAP alloy exhibited a weak direct yield asymmetry along the ED. After aging, the tensile and compressive yield strengths of the ECAP alloy increased to 409 and 402 MPa, respectively, owing to the coprecipitation of basal γ'' and prismatic β' nanoplates, manifesting a near-symmetric yield response. Moreover, two strain-hardening stages (stage I and stage III) were detected in tensile deformation for all the investigated alloys, while all three stages were observed in compressive deformation. Both the strain-hardening ability and strength in the ECAP alloy before and after aging decreased slightly in the following order: ED > transverse direction (TD) > normal direction (ND), representing low anisotropy. In short, the present ECAP Mg–10.6Gd–2Ag alloy exhibited the advantages of high strength and ductility, near-symmetric yield response, and low anisotropy.

Microstructures and Mechanical Properties of Precipitation-Hardenable Magnesium–Silver–Calcium Alloy Sheets

Precipitation hardening provides one of the most common strengthening mechanisms for magnesium (Mg) alloys. Here, we report a new precipitation-hardenable Mg sheet alloy based on the magnesium–silver–calcium system. In a solution treated condition (T4), the strength of Mg–xAg–0.1Ca alloys is enhanced with increasing the Ag content from 1.5 wt.% to 12 wt.%. The Mg–12Ag–0.1Ca (wt.%) alloy sheet shows moderate tensile yield strengths of 193 MPa, 130 MPa, 117 MPa along the rolling direction (RD), 45° and transverse direction (TD) in the T4-treated condition. Subsequent artificial aging at 170 °C for 336 h (T6) increases the tensile yield strengths to 236 MPa, 163 MPa and 143 MPa along the RD, 45° and TD, respectively. This improvement in the tensile yield strength by the T6 treatment can be ascribed to the formation of AgMg4 precipitates lying on the {112¯0}ɑ and pyramidal planes. Our finding is expected to stimulate the development of precipitation-hardenable Mg–Ag-based wrought alloys with high strength.

Alloy Design, Thermodynamics, and Electron Microscopy of Ternary Ti-Ag-Nb Alloy with Liquid Phase Separation.

The Ti–Ag alloy system is an important constituent of dental casting materials and metallic biomaterials with antibacterial functions. The binary Ti–Ag alloy system is characterized by flat liquidus lines with metastable liquid miscibility gaps in the phase diagram. The ternary Ti–Ag-based alloys with liquid phase separation (LPS) were designed based on the mixing enthalpy parameters, thermodynamic calculations using FactSage and Scientific Group Thermodata Europe (SGTE) database, and the predicted ground state diagrams constructed by the Materials Project. The LPS behavior in the ternary Ti–Ag–Nb alloy was investigated using the solidification microstructure analysis in arc-melted ingots and rapidly solidified melt-spun ribbons via trans-scale observations, combined with optical microscopy (OM), scanning electron microscopy (SEM) including electron probe micro analysis (EPMA), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). The solidification microstructures depended on the solidification processing in ternary Ti–Ag–Nb alloys; macroscopic phase-separated structures were observed in the arc-melted ingots, whereas fine Ag globules embedded in the Ti-based matrix were observed in the melt-spun ribbons.

Analysis of vascular inflammation against bioresorbable Zn-Ag based alloys.

Zinc (Zn) has emerged as a promising bioresorbable stent material due to its satisfactory corrosion behavior and excellent biocompatibility. However, for load bearing implant applications, alloying is required to boost its mechanical properties as pure Zn exhibits poor strength. Unfortunately, an increase in inflammation relative to pure Zn is a commonly observed side-effect of Zn alloys. Consequently, the development of a Zn-based alloy that can simultaneously feature improved mechanical properties and suppress inflammatory responses is a big challenge. Here, a bioresorbable, biocompatible Zn-Ag-based quinary alloy was comprehensively evaluated in vivo, in comparison to reference materials. The inflammatory and smooth muscle cellular response was characterized and correlated to metrics of neointimal growth. We found that implantation of the quinary alloy was associated with significantly improved inflammatory activities relative to the reference materials. Additionally, we found that inflammation, but not smooth muscle cell hyperplasia, significantly correlates to neointimal growth for Zn alloys. The results suggest that inflammation is the main driver of neointimal growth for Zn-based alloys and that the quinary Zn-Ag-Mn-Zr-Cu alloy may impart inflammation-resistance properties to arterial implants.

Microchemical Investigation of Long-Term Buried Gilded and Silvered Artifacts From Ancient Peru

A large number of metal artefacts with exceptional artistic value of the Moche culture have been found in the tombs of the Lords of Sipan (Lambayeque, Peru) and of the Lady of Cao (El Brujo, Peru) characterised by different burial conditions. Some of the objects, dated around 300-400 AD, are constituted by substrates of Cu- or Ag-based alloys coated by uniformly distributed thin films of precious metal (1 - 4 microns) that create also polymetallic bicoloured surfaces with “gold” and “silver” areas. In order to investigate the corrosion product structure and composition as well as to identify the techniques used to give the gold or silver appearance, an integrated analytical approach has been adopted. The selected complementary methodologies were scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM). The findings reveal that the substrates are mainly composed by Cu-Ag-Au alloys that at the site of Sipan have been almost completely corroded during the burial. Furthermore, the results show that the main aggressive agent is Cl- coming from the soil and that the degradation phenomena were likely enhanced by the galvanic coupling between the precious metal layer and the less noble substrate. The degradation products have formed mainly layered structures containing chloroargyrite (AgCl), cuprite (Cu2O), nantokite (CuCl), and atacamite (CuCl23Cu(OH)2) polymorphs. These latter species warn that dangerous copper cyclic corrosion is occurring, a harmful phenomenon, commonly defined as “bronze disease”, which must be be firmly mitigated. Finally, the findings reveal that the Moche metal workers used the depletion gilding to selectively modify the surface chemical composition of the artefacts to produce the Ag or Au thin films. According to this subtractive method, the surface of the Cu-Au-Ag alloys was enriched with a layer of precious metal by means of cycles of thermal treatments and removal of Cu or both Cu and Ag from the outermost region by using pickling solutions.

Effect of cooling rate on hardness and microstructure of Pd–Ag–In–Sn−Ga alloy during porcelain firing simulation

This study examined the effect of the cooling rate on the hardness and its effect on the microstructure during porcelain firing simulation of a Pd–Ag–In–Sn−Ga metal-ceramic alloy. In practice, after each firing step for porcelain bonding, the prosthesis is cooled to room temperature before proceeding to the next firing step. The cooling step is known to allow the hardness of the metal substructure to increase. The aim of the study was to determine whether controlling the cooling rate after each porcelain-firing step increases the hardness of the Pd–Ag-based metal-ceramic alloy. The results showed that the hardness of specimens cooled at a higher cooling rate increased after each firing step compared to specimens cooled at a lower cooling rate (p < 0.05). During cooling after the firing simulation the InPd3–based phase of tetragonal structure precipitated from the Pd–Ag-rich matrix of the face-centered cubic structure. Hardening by cooling at a higher cooling rate after firing was the result of the coherency strains that formed at the interface of the Pd–Ag-rich matrix and the metastable phase based on the InPd3 phase. . The reduced hardness obtained in the specimen cooled at a lower cooling rate after firing resulted from the loss of coherency strains as the fine metastable phases based on the InPd3 phase were transformed into the coarser stable phase with decreased (c/a) of 0.88. This finding revealed that controlling the cooling rate during porcelain firing simulation improves the hardness of the Pd–Ag–In–Sn−Ga metal-ceramic alloy without an additional heat treatment of the alloy.

Correlation between Crystal-Geometry Parameters and Structural-Phase States in the Alloys Based on Ag–Me (Me = Co, Rh, Ir, Ni, Pd, Pt, Cu, Au)

The results of a search for correlations between the crystal-geometry parameters and structural-phase states in the alloys based on Ag–Me (Me = Co, Rh, Ir, Ni, Pd, Pt, Cu, Au) are presented. The limits of numerical values of the crystal-geometry and thermodynamic factors are identified, within which inorganic regions of solid solutions are formed in the state diagrams of binary systems or monotectic reactions take place in the systems due to a limited solubility of the system components in liquid states. It is shown that an approach relying on the analysis of state diagrams, including the crystal-geometry and thermodynamic factors of the alloy-forming elements into consideration, is promising in searching for common patterns of structural-phase states in the Ag-based alloys; it is found out that an Ag–Pt system is the most attractive binary system in this respect. A slight deviation of the experimental concentration dependences of the atomic volume in the solid solutions of the Ag–Pd and Ag–Au systems from the Zen relation is observed in intermetallic compounds in the alloys of the Ag–Pt system.

Heterogeneous metal alloy engineering: embryonic growth of M13 icosahedra in Ag-based alloy superatomic nanoclusters.

Alloying is an effective tool to comprehend the packing mechanism and adjust the properties of nanomaterials. Herein, two crystal structures of alloy nanoclusters with M13 icosahedron cores, formulated as [Pt2Ag51(S-Adm)28(PPh3)2Cl7](SbF6)2 and [Au3Ag48(S-Adm)28Cl7](SbF6)2, are determined. The preferable site(s) of alloy metals in M13 induces various packing patterns of M13. The Pt2Ag21 and Au3Ag22 kernels are observed in Pt2Ag51 and Au3Ag48, respectively. The electronic structures of these two nanoclusters are evaluated. Overall, this work presents the effect of alloying on the packing patterns of M13 and electronic structures of the metal nanoclusters.