Thermodynamic assessments of the Ag-Ni binary and Ag-Cu-Ni ternary systems

The phase diagram of the Ag-Ni binary system has been evaluated by using the calculation of phase diagrams (CALPHAD) method based on experimental data of the phase equilibria and thermodynamic properties. Gibbs free energies of the liquid and fcc phases were described by the subregular solution model with the Redlich-Kister equation. On the basis of the thermodynamic parameters of the Ag-Ni, Ag-Cu, and Cu-Ni systems, and experimental information of the phase equilibria in the Ag-Cu-Ni system, the thermodynamic assessment in the Ag-Cu-Ni system was carried out. The calculated results in both the Ag-Ni and Ag-Cu-Ni systems are in reasonable agreement with experimental data

Effects of anharmonic strain on phase stability of epitaxial films and superlattices: applications to noble metals

Epitaxial strain energies of epitaxial films and bulk superlattices are studied via first-principles total energy calculations using the local-density approximation. Anharmonic effects due to large lattice mismatch, beyond the reach of the harmonic elasticity theory, are found to be very important in Cu/Au (lattice mismatch 12%), Cu/Ag (12%) and Ni/Au (15%). We find that is the elastically soft direction for biaxial expansion of Cu and Ni, but it is for large biaxial compression of Cu, Ag, and Au. The stability of superlattices is discussed in terms of the coherency strain and interfacial energies. We find that in phase-separating systems such as Cu-Ag the superlattice formation energies decrease with superlattice period, and the interfacial energy is positive. Superlattices are formed easiest on (001) and hardest on (111) substrates. For ordering systems, such as Cu-Au and Ag-Au, the formation energy of superlattices increases with period, and interfacial energies are negative. These superlattices are formed easiest on (001) or (110) and hardest on (111) substrates. For Ni-Au we find a hybrid behavior: superlattices along and like in phase-separating systems, while for they behave like in ordering systems. Finally, recent experimental results on epitaxial stabilization of disordered Ni-Au and Cu-Ag alloys, immiscible in the bulk form, are explained in terms of destabilization of the phase separated state due to lattice mismatch between the substrate and constituents.Comment: RevTeX galley format, 16 pages, includes 9 EPS figures, to appear in Physical Review

Особенности распределения тяжелых металлов в донных отложениях северо-восточного региона Черного моря

Рассматривается распределение Fe, Mn, Co, Ni, Cu, Zn, Cd, Hg, Ag и Au в современных черноморских, древнечерноморских и новоэвксинских донных отложениях, пробы которых были отобраны в 1990 г. в Крымском, Керченско-Таманском и Кавказском районах северо-восточного региона Черного моря в зонах шельфа, склона и глубоководной впадины. Выявленный характер полей концентраций изученных металлов не позволил установить четких закономерностей в распределении Mn, Co и Cu с Fe. Показано, что значение соотношений концентраций металлов увеличивается в направлении Au/Cu → Zn/Cu → Co/Fe → Ni/Fe → Mn/Fe → Hg/Cu → Ag/Cu → Cu/Fe. Сведения о Ag представлены впервые.Розглядається розподіл Fe, Mn, Co, Ni, Cu, Zn, Cd, Hg, Ag і Au в сучасних чорноморських, давньочорноморських і новоевксінських донних відкладеннях, проби яких були відібрані в 1990 р. в Кримському, Керченсько-Таманському та Кавказькому районах північно-східного регіону Чорного моря в зонах шельфу, схилу і глибоководної западини. Виявлений характер полів концентрацій вивчених металів не дозволив встановити чітких закономірностей в розподілі Mn, Co і Cu з Fe. Показано, що значення співвідношень концентрацій металів збільшується у напрямі Au/Cu ® Zn/Cu ® Co/Fe ® Ni/Fe ® Mn/Fe ® Hg/Cu ® Ag/Cu Cu/Fe. Відомості про Ag отримані вперше.Distribution of Fe, Mn, Co, Ni, Cu, Zn, Cd, Hg, Ag and Au in present and ancient bottom sediment in the shelf, slope and deep trench zones of the Black Sea northeastern region is considered. The samples were taken in 1990 in the Crimean, Kerch-Taman’ and Caucasian regions. The revealed character of the concentration fields of the metals under study does not permit to define exact regularities in the distribution of Mn, Co and Cu with Fe. It is shown that the value of correlations of the metals’ concentrations grows in the following direction: Au/Cu → Zn/Cu → Co/Fe → Ni/Fe → Mn/Fe → Hg/Cu → Ag/Cu → Cu/Fe. Information on Ag is represented for the first time

Metal concentrations in Sungai Sedili Kecil, Johor, Peninsular Malaysia

Water and sediment from five sampling stations in Sungai Sedili Kecil were sampled in October 2010 and analyzed for 11 metals including cadmium (Cd), copper (Cu), manganese (Mn), iron (Fe), lead (Pb), aluminium (Al), zinc (Zn), nickel (Ni), cobalt (Co), arsenic (As) and argentum (Ar). Results showed that the mean dissolved metal concentrations (in μg/L) in Sungai Sedili waters based on 5 sampling stations (in descending order) for Fe, Al, Zn, Cu, As, Mn, Ni, Pb, Co, Cd and Ag were 443.7, 52.7, 50.2, 34.2, 25.9, 20.3, 6.8, 1.4, 0.77, 0.67 and 0.10 μg/L, respectively. Mean metal concentrations (in μg/g dry weight) for sediments (in descending order) for Fe, Al, Mn, Zn, Pb, Cu, As, Ni, Co, Cd and Ag were 33389.4, 17118.7, 190.5, 55.1, 29.1, 26.3, 19.3, 10.9, 4.7, 0.18 and 0.12 μg/g, respectively. A comparison with various water and sediment quality standards showed that the mean metal concentrations in surface water and sediment of Sungai Sedili Kecil were low and within the range of natural background except for Cu and Fe in water

Electrophoretic Immobilization Of TIO 2 Photocatalyst On AL,CU,CU/NI And Pet Plates For Photodegradation Of Phenol [QD716.P45 L732 2004 f rb] [Microfiche 7557].

Fotomangkin terpegun Al/TiO2, Al/ENRTiO2, Cu/ENRTiO2, Cu/Ni/ENRTiO2, PET/Ag/ENRTiO2 dan PET/C/ENRTiO2 disediakan dengan kaedah pengenapan elektroforetik terubahsuai. Immobilized photocatalysts referred to as Al/TiO2, Al/ENRTiO2, Cu/ENRTiO2, Cu/Ni/ENRTiO2, PET/Ag/ENRTiO2 and PET/C/ENRTiO2 were prepared by modified electrophoretic deposition method

Development Of Ternary Ni-Ag-P And Ni-Cu-P Using Electroless Coating On Copper Substrate

Current functional test of assembled device in semiconductor industry use thermal interface media but it occasionally caused cosmetic defects such as stain or scratch mark. A possible solution to eliminate the undesired defects is by improving the nickel-phosphorus (Ni-P) coating currently applied on the test chuck in terms of the ability to conduct heat transfer efficiently and thus eliminate the use of thermal interface media. Co-deposition of argentum (Ag) and copper (Cu) into Ni-P coating are expected to improve the thermal conductivity of Ni-P coating without sacrificing other coating’s properties; surface roughness, thickness, hardness and wear resistance. Ni-P coating in this work was prepared via electroless coating on a copper substrate. The experimental work began by developing the coating solution in order to achieve targeted phosphorus content, thickness and surface roughness. To produce ternary nickel-argentum-phosphorus (Ni-Ag-P) and nickel-copper-phosphorus (Ni-Cu-P) coating, argentum and copper salt were added into the coating solution. The best ternary coating was observed on coating containing 5 mg/L argentum sulphate and 10 mg/L copper sulphate with co-deposition of 1.14 wt.% Ag and 3.56 wt.% Cu respectively. Both ternary coating produced have smoother surface with lower wear rate compared to binary Ni-P coating. Improvement in wear resistance is related to the hardness of coating, in which Ni-Ag-P has highest hardness (394.08 HK) followed by Ni-P (380.78 HK) and Ni-Cu-P (365.34 HK). Even though Ni-Cu-P coating possess low hardness, its low surface roughness contributed to the low wear rate. The thermal conductivity for ternary Ni-Ag-P coating (451.10 W/m.K) was higher than Ni-P (445.70 W/m.K) and Ni-Cu-P coating (326.91 W/m.K). The result is as expected as argentum has higher conductivity compared to nickel, and thus addition of argentum is able to improve thermal conductivity of Ni-P coating

Liquid phase separation in Ag-Co-Cr-Fe-Mn-Ni, Co Cr-Cu-Fe-Mn-Ni and Co-Cr-Cu-Fe-Mn-Ni-B high entropy alloys for biomedical application

The liquid phase separation (LPS) behavior in Co-Cr-based high-entropy alloys (HEAs) is an important target for the development of Co-Cr-based HEAs for metallic biomaterials (BioHEAs). The solidification microstructure in Ag-Co-Cr-Fe-Mn-Ni-Ag, Co-Cr-Cu-Fe-Mn-Ni-Cu, and Co-Cr-Cu-Fe-Mn-Ni-B HEAs, which were designed as the combination of the equiatomic CoCrFeMnNi with Ag, Cu, and the interstitial element of B, was investigated as the fundamental research of LPS in Co-Cr-based HEAs. Ingots of equiatomic AgCoCrFeMnNi, equiatomic CoCrCuFeMnNi, non-equiatomic CoCrCuxFeMnNi (x = 2, 3), and CoCrCuxFeMnNiB0.2 (x = 1, 2, 3) with a small amount of B were fabricated using the arc-melting process. A macroscopic phase-separated structure was observed in the ingots of the equiatomic AgCoCrFeMnNi and CoCrCuxFeMnNiB0.2 (x = 2, 3) HEAs. The addition of a small amount of B enhanced the LPS tendency in the Co-Cr-Fe-Mn-Ni-Cu HEAs. The LPS behavior was discussed through the heat of mixing and computer coupling of phase diagrams and thermochemistry (CALPHAD).Nagase T., Todai M., Nakano T.. Liquid phase separation in Ag-Co-Cr-Fe-Mn-Ni, Co Cr-Cu-Fe-Mn-Ni and Co-Cr-Cu-Fe-Mn-Ni-B high entropy alloys for biomedical application. Crystals, 10, 6, 1. https://doi.org/10.3390/cryst10060527

Оцінка можливості здійснення деяких металургійних процесів (плавка, синтез сплавів, пайка) у середовищі, наближеному до атмосфери на планеті Марс

Для перевірки можливості реалізації деяких металургійних процесів у середовищі, наближеному до атмосфери на планеті Марс, проведено досліди по плавленню ряду металів та синтезу сплавів, що широко використовуються у металургії (Cu, Ag, Sn, Pb, Ni, Cu—Ag), і вивчено змочування підкладок із сталі, нікелю та кераміки сріблом, міддю та припоями в атмосфері СО₂, подібній до марсіанської. Отримані зливки металів/сплавів високої якості і дані по змочуванню свідчать про принципову можливість здійснення зазначених процесів на планеті Марс.Для проверки возможности реализации некоторых металлургических процессов в среде, приближенной к атмосфере на планете Марс, проведены исследования по плавлению ряда металлов и синтезу сплавов, которые широко используются в металлургии (Cu, Ag, Sn, Pb, Ni, Cu—Ag), и изучена смачиваемость подложек из стали, никеля и керамики серебром, медью и припоями в атмосфере СО₂, подобной марсианской. Полученные слитки металлов/сплавов высокого качества и данные по смачиваемости свидетельствуют о принципиальной возможности осуществления указанных процессов на планете Марс.To check a possibility of realization of some metallurgical processes (melting, synthesis of alloys, brazing) in the atmosphere similar to that of Mars, some experiments on melting and synthesis were carried out for a number of metals and alloys widely used in metallurgy (Cu, Ag, Sn, Pb, Ni, Cu—Ag), and wettting of steel, nickel and ceramic supports by silver, copper and solders in the atmosphere of СО₂ was studied. Good quality metal/alloys ingots and also wettability data obtained may serve as an evidence of a possibility to realize in principle some metallurgical technologies in the atmosphere of Mars

Microstructure and interfacial reactions during active metal brazing of stainless steel to titanium

Microstructural evolution and interfacial reactions during active metal vacuum brazing of Ti (grade-2) and stainless steel (SS 304L) using a Ag-based alloy containing Cu, Ti, and Al was investigated. A Ni-depleted solid solution layer and a discontinuous layer of (Ni,Fe)2TiAl intermetallic compound formed on the SS surface and adjacent to the SS-braze alloy interface, respectively. Three parallel contiguous layers of intermetallic compounds, CuTi, AgTi, and (Ag,Cu)Ti2, formed at the Ti-braze alloy interface. The diffusion path for the reaction at this interface was established. Transmission electron microscopy revealed formation of nanocrystals of Ag-Cu alloy of size ranging between 20 and 30 nm in the unreacted braze alloy layer. The interdiffusion zone of β-Ti(Ag,Cu) solid solution, formed on the Ti side of the joint, showed eutectoid decomposition to lamellar colonies of α-Ti and internally twinned (Cu,Ag)Ti2 inter- metallic phase, with an orientation relationship between the two. Bend tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the Ti- braze alloy interface, through the (Ag,Cu)Ti2 phase layer