Ag Melting Research Articles

Enhancing overall performances of Cu/Ag/AZO multilayer films for transparent heaters via laser/furnace step-by-step annealing mode

Four different step-by-step annealing modes based on furnace and/or laser annealing (i.e. F + L, F + F, L + F and L + L) were developed and compared with one-step furnace or laser annealing mode (i.e. F and L), with an aim to enhance overall performances of Cu/Ag/AZO (CAA) multilayer films applied to transparent heaters. It was found that the L + F step-by-step annealing mode improved the transmittance and conductivity of the CAA film to the greatest extent, and therefore the resulting sample L + F achieved the best overall performance with a figure of merit of 4.26 × 10−2 Ω−1. These results should be ascribed to that laser annealing for the AZO layer in the first step facilitated growth and recrystallization of AZO grains to provide better nucleation sites for overlying Ag and Cu grains, and furnace annealing of the whole CAA film in the second step promoted the melting of the surface Ag and Cu grains to re-aggregate with the nearby AZO grains. The transparent heater prepared from the sample L + F exhibited a high steady-state temperature of 127.1 °C within a short response time of 80 s under an input voltage of 3 V, as well as good heating stability and effective deicing function.

Photoluminescence and electronic structure of α'-Ag8GeS6 crystals

The Ag8GeS6 crystal was synthesized by the direct melting of the elementary Ag, Ge, and S high-purity grade stoichiometric mixture in a sealed quartz ampoule. This argyrodite crystallizes in orthorhombic structure [Pna21 space group (No. 33)] below ≈483 K. The theoretical first-principle calculations of the electronic band structure and density of states of an α'-Ag8GeS6 crystal are estimated by the generalized gradient approximation. The Perdew–Burke–Ernzerhof functional was utilized. All of the calculated parameters correlate well with the known experimental data. Based on the electronic band structure, the effective mass of the electrons and holes was calculated. The anisotropic behavior of electronic band structure is discussed. Temperature and carrier concentration dependence of the Seebeck coefficient is calculated. The temperature behavior of α'-Ag8GeS6 photoluminescence spectra is presented. The emission spectra are studied in the temperature range between 17 and 130 K and laser power excitation between 4 and 512 mW and in the spectral range of 750–1650 nm. Two main emission bands at ≈1.35 and ≈1.57 eV are observed and discussed.

Acoustic Studies of the Melting and Crystallization of Eutectic Gallium–Silver Alloys in Porous Glasses

The paper presents the results of acoustic studies of the melting and crystallization of Ag–Ga alloys with a silver content of 1.5 and 3 at % embedded into porous glasses with an average pore size of 13 nm. The temperature dependences of the velocity of longitudinal ultrasonic waves are measured by a modified pulse-phase method at a frequency of 7 MHz in the 200–325 K range for complete and partial cooling–heating cycles. The temperature dependences of the ultrasonic velocity showed regions corresponding to phase transitions. Significant changes in the phase diagram of the bulk alloy due to nanostructuring have been revealed. It is shown that segregates with different crystal structures are formed in the pores for alloy of different compositions.

NaYW2O8: A novel glass-free microwave dielectric ceramic for LTCC application

Microwave dielectric ceramics are important materials for wireless communication devices because of their excellent dielectric properties. Tungstenate compounds with multiple scheelite structures can be used in low temperature co-fired ceramic (LTCC) devices because of their low densification temperature and high-quality factor. In this study, NaYW2O8 ceramics (NYW) were synthesized by a solid-state reaction method at a low densification temperature below the Ag melting point. The microstructure, morphology and microwave dielectric properties of NYW ceramics were investigated, and the effects of packing fraction and lattice energy on microwave dielectric properties were studied. The results showed that the microwave dielectric properties of NYW ceramics were influenced by the grain size and porosity, and deteriorated with the increase of porosity. In addition, the stacking fraction and lattice energy shared a similar trend with the quality factor. The NYW ceramics sintered at 925 °C exhibited excellent microwave dielectric properties with εr= 10.8, Q × f = 49,800 GHz (at 10.5 GHz), and τf= −26.5 ppm/°C. In particular, the NYW ceramics were found to have an excellent chemical compatibility with Ag. The above results indicate the NYW ceramics are candidate in LTCC applications.

Wetting and spreading of Pb, Pb-Cu, and Ag-Cu melts on a polycrystalline copper surface with cobalt particles

The specific feature of Cu(Co) solid solutions with a sub-solidus composition involves the formation of submicron-sized cobalt particles on the free surface. In this work, Cu(Co) substrates with cobalt particles on the surface were produced through the annealing of a series of copper-based cobalt solid solutions containing 1–3 at% Co in a hydrogen atmosphere at 1050 °C, leading to the formation of a family of cobalt-based submicron-sized particles with a similar orientation within one grain on the surface. The wetting and spreading of lead and copper-based liquid alloys on the surfaces of these substrates were compared to the wetting of pure copper and pure cobalt. Experiments were conducted via the high-speed video recording of droplet transfer onto the Cu, Co, and Cu(Co) substrates at 400 °C (melt: pure lead), at 850 °C (Pb + 10.3 at% Cu), and at 1070 °C (Cu + 2.5 at% Ag) in a vacuum. The contact angle of the Pb melt on cobalt (46°) differed significantly from the contact angle on copper at 400 °C (32°), while at 850 °C, the wetting for both metals was almost complete (the wetting angles for Cu and Co were 5° and 7°, respectively). The wetting angle for the Cu(Co) solid solution surface with cobalt particles was almost equal to that for pure copper, and the spreading rates were comparable for the two cases. The wetting of the Cu, Co, and Cu(Co) surfaces by the Cu(Ag) melt did not demonstrate any significant differences between the equilibrium contact angles (tending to zero), while the spreading rate differed only slightly. The surface area covered by the particles reached 20%, despite the presence of the particles, which exerted no impact on the contact angle, due to two possible effects: (i) the formation of an adsorbed copper layer on the surface of the cobalt phase confirmed by room-temperature Auger electron spectroscopy, and (ii) the compensation of wetting deterioration by an increase in roughness.

Phase-transforming Ag-NiTi 3-D interpenetrating-phase composite with high recoverable strain, strength and electrical conductivity

It is of particular interest to achieve high elastic recoverable strain in the electrical contact materials while maintaining good electrical conductivity and decent tensile strength. It remains a challenge, especially for bulk-sized metallic materials, as the electrical conductivity and elastic strain limit (or tensile strength) are often mutually exclusive. Here, we present a material design strategy for overcoming this conflict by developing a Ag-NiTi composite with an interpenetrating-phase architecture via infiltrating Ag melt into the partially sintered porous NiTi scaffold. The composite exhibits a good combination of properties with high electrical conductivity comparable to metals, large elastic recoverable strain superior to most of bulk-sized conductive metals as well as higher tensile strength than most of alloys/composites based on silver and other noble metals. This new finding demonstrates that the interpenetrating-phase architecture design is promising for developing new materials for electrical contact application.

Ag içeren dolgu metalleri ile elde edilen bakır/pirinç lehim bağlantısının mikroyapısı ve mekanik performansı üzerine çalışma

Ag is used as a useful alloying element in brazing filler metals. It is clear that the addition of Ag has a positive effect on the melting temperature, wettability, conductivity and mechanical property of the filler metals. For this reason, although Ag is very expensive, it is still widely used in many research and production. In this study, it was focused on obtaining both high strength and cost-effective brazing joints by using filler metals containing different levels of Ag. Melting-solidification temperatures, mechanical properties and microstructures of brazing joints obtained with filler metals containing different levels of Ag-Cu-Zn and Cd were investigated. In this study, the appropriate Ag content in brazing processes of pipes and caps used as copper-brass material pairing in cooling-heating devices in the air conditioning system was investigated in detail. When the typical microstructure of the joints was examined, it was observed that it mainly consisted of solid solutions and eutectic phases. The interfaces in the copper and brass regions were affected by both Ag content and melting temperatures. As a result of the burst test, the maximum stress value at which the brazed material pairs were damaged was found to be 345 MPa, and the damage was reported to occur in the copper pipe. In addition, it has been reported that the final product is damaged from the brazed zone when Ag-free solder wire is used. It was found that 5%Ag content provides sufficient performance in the final product due to the fact that the strength of the braze joint with low-Ag content is higher than the copper tube. The results also showed that the micro-hardness increased with the increase of Ag-addition, the hardness of the joint with the filler metal containing 5%Ag increased by 21%. The joint hardness obtained with filler metal containing 40% Ag showed an increase of up to 57%. This showed that the addition of Ag improves the strength, but its 5% Ag content provides sufficient performance in the brazing joint.

Controllable Melting and Flow of Ag in Self-Formed Amorphous Carbonaceous Shell for Nanointerconnection.

Nanointerconnection has been selected as a promising method in the post-Moore era to realize device miniaturization and integration. Even with many advances, the existing nanojoining methods still need further developments to meet the three-dimensional nanostructure construction requirements of the next-generation devices. Here, we proposed an efficient silver (Ag)-filled nanotube fabrication method and realized the controllable melting and ultrafine flow of the encapsulated silver at a subfemtogram (0.83 fg/s) level, which presents broad application prospects in the interconnection of materials in the nanometer or even subnanometer. We coated Ag nanowire with polyvinylpyrrolidone (PVP) to obtain core–shell nanostructures instead of the conventional well-established nanotube filling or direct synthesis technique, thus overcoming obstacles such as low filling rate, discontinuous metalcore, and limited filling length. Electromigration and thermal gradient force were figured out as the dominant forces for the controllable flow of molten silver. The conductive amorphous carbonaceous shell formed by pyrolyzing the insulative PVP layer was also verified by energy dispersive spectroscopy (EDS), which enabled the continued outflow of the internal Ag. Finally, a reconfigurable nanointerconnection experiment was implemented, which opens the way for interconnection error correction in the fabrication of nanoelectronic devices.

Improved arc erosion resistance of Ag/SnO2 composites fabricated by Ag melt-infiltration in the SnO2 skeleton

The typical Ag-SnO2 contact materials in which SnO2 dispersing in the Ag matrix suffer a poor arc erosion resistance because the individual SnO2 particles segregate and form a SnO2-rich layer under repeated arcing. Here, we introduce an architectured Ag/SnO2 composites in which individual SnO2 particles are bonding into a skeleton, fabricated by a novel method: (i) creating a porous SnO2 matrix by sintering SnO2 powders with NaCl space-holders, (ii) then infiltrated by Ag melt in the air. 95% relative density is achieved for the Ag/SnO2 composites. The microstructure evolution during the sintering and infiltration are investigated. 10,000 times make-and-break operations are conducted to evaluate the arc erosion resistance of the architectured composite, the temperature rise of the prepared Ag-60vol.%SnO2 composite decreases ∼90% compared with the particle dispersed composites. The microstructure of the arc-erased layer is analyzed and reveals that the SnO2 skeleton effectively suppresses the formation of the SnO2-rich layer, providing good arc erosion resistance and the potential for long lifetime contacts.

Effect of external static magnetic field on the particle distribution, the metallurgical process and the microhardness of Sn3.5Ag solder with magnetic Ni particles

PurposeThis paper aims to investigate the mechanism of Ni particles distribution in the liquid Sn3.5Ag melt under the external static magnetic field. The control steps of Ni particles and the Sn3.5Ag melt metallurgical process were studied. After aging, the microhardness of pure Sn3.5Ag, Sn3.5Ag containing randomly distributed Ni particles and Sn3.5Ag containing columnar Ni particles were compared.Design/methodology/approachPlace the sample in a crucible for heating. After the sample melts, place a magnet directly above and below the sample to provide a magnetic field. Sn3.5Ag with the different morphological distribution of Ni particles was obtained by holding for different times under different magnetic field intensities. Finally, pure Sn3.5Ag, Sn3.5Ag with random distributed Ni particles and Sn3.5Ag with columnar Ni particles were aged and their microhardness was tested after aging.FindingsThe experimental results show that with the increase of magnetic field strength, the time for Ni particle distribution in Sn3.5Ag melt to reach equilibrium is shortened. After aging, the microhardness of Sn3.5Ag containing columnar nickel particles is higher than that of pure Sn3.5Ag and Sn3.5Ag containing randomly distributed nickel particles. A chemical reaction is the control step in the metallurgical process of nickel particles and molten Sn3.5Ag.Originality/valueUnder the action of the magnetic field, Ni particles in Sn3.5Ag melt will be arranged into columns. With the increase of magnetic field strength, the shorter the time for Ni particles in Sn3.5Ag melt to arrange in a column. With the extension of the service time of the solder joint, if Sn3.5Ag with columnar nickel particles is used as the solder joint material, its microhardness is better than Sn3.5Ag with arbitrarily distributed nickel particles and pure Sn3.5Ag.

Effect of the Ag addition on the compressibility, sintering and properties of Ti6Al4V/xAg composites processed by powder metallurgy

This work investigates the fabrication of Ti6Al4V/xAg composites processed by powder metallurgy. An atomized Ti6Al4V powder was blended with 0, 5, 10, 15 and 20 vol% of Ag particles, compacted in a die, and sintered above Ag melting point. The compressibility of the mixtures was analyzed, and the sintering kinetics was evaluated by dilatometry tests. The characterization of sintered samples by microtomography, SEM and diffraction analysis allowed determining the effect of Ag amount on the sintering process and on microstructural changes arising during sintering. The mechanical properties of sintered materials were investigated by microhardness. The compressibility of Ti6Al4V powder was found to be improved by adding soft Ag particles, which resulted in denser packing and larger plastic deformation. The densification during compaction can be predicted by Heckel model and the rule of mixture. It was next found that sintering was driven by volume diffusion in the solid state for Ag content lower than 10 vol% and involved a liquid phase for Ag content higher than 15 vol%. In the latter case, the liquid fills the interconnected pores under the action of capillary forces as the quantity of liquid increased. The microstructure was composed mainly of α-Ti, Ti2Ag, and Ag, which filled the pores between Ti6Al4V particles. Microhardness data showed a maximum value with 20 vol% of Ag. This value is similar to those reported for highly dense Ti6Al4V. It has thus proved that close to full-dense Ti6Al4V/20Ag composites can be processed by powder metallurgy.

Ag droplets nano-shape design on SiC: Study on wetting and energetics

This work describes the effect of the annealing temperature on the size and wetting of nanostructures obtained on 4H–SiC substrate by the dewetting process of a deposited nanoscale-thick Ag film. The work focuses, in particular, on the difference between solid-state dewetting (below Ag melting temperature) and liquid-state dewetting (above Ag melting temperature). Following the deposition of a 58 nm-thick Ag film on the SiC substrate, annealings were perfomed at 800 °C, 850 °C and 885 °C so to induce the Ag film solid-state dewetting. In addition, annealing at 1040 °C was performed so to induce the Ag film liquid-state dewetting. The dewetting processes led to the formation of nanostructures on the SiC surface. Plan-view and cross-view scanning electron microscopy analyses were carried out to quantify the evolution of the average planar size and of the average contact angle (to the SiC surface) of the Ag nanostructures versus the annealing temperature. These analyses allowed us to extract information on the wetting behavior of the nanostructures on the SiC surface by calculating the temperature-dependent adhesion work. In fact, the nanostructures obtained by the 800 °C and 850 °C processes show mean contact angle of 118,9° and 117,4°, respectively, and mean work of adhesion of 0,45 and 0,48 J/m2, respectively. On the other hand, the nanostructures obtained by the 885 °C and 1040 °C show mean contact angle of 48,3° and 52,2° respectively, and work of adhesion of 1,45 and 1,40 J/m2, respectively. The variation of the wetting properties is identified in Si diffusion from the SiC substrate to the Ag nanostructures at the higher temperatures, as confirmed by energy dispersive x-ray analyses. Finally, the optical properties of the Ag nanostructures/SiC systems were probed by absorbance and transmittance measurements allowing to recognize the occurrence of a peak around 460 nm which is attributed to localized surface plasmon resonances due to the Ag nanostructures.

Incoherent-light pulse annealing of nanoporous germanium layers formed by ion implantation

The study addresses the monocrystalline c-Ge substrates implanted by Ag+ ions with the energy of 30 keV, irradiation dose of 7.5·1016 ion/cm2 at current density of 8 μA/cm2 and annealed by incoherent-light pulse. By scanning electron microscopy and optical reflection spectroscopy measurements it was shown that after ion implantation an amorphous porous Ag:PGe layer of a spongy structure with nanowires on the c-Ge substrate were formed. Pulsed light annealing of the implanted samples leads to partial melting and recrystallization of the surface Ag:PGe layer. The spongy annealed structure of the Ag:PGe layer was not destroyed, however the diameters of nanowires increased by about 1,5 times.

Origin of high piezoelectricity in low-temperature sintering PZT-based relaxor ferroelectric ceramics

Multilayer piezoelectric devices need to co-sinter the piezoelectric ceramic layers and the Ag-rich Ag–Pd internal electrode layers at a low temperature (less than the Ag melting point of 961.78 °C), and need to use Sn–Zn-based lead-free solder to weld the components at 260 °C. This requires low-temperature sintering of high-performance piezoelectric ceramics with a Curie temperature (Tc) higher than 260 °C. Thereby low-temperature (940 °C) sintering 0.09 Pb(Ni1/3Nb2/3)O3‒ 0.03 Pb(Mg1/2W1/2)O3‒0.88 Pb(Zr0.5Ti0.5)O3 ceramics are prepared via the solid-state reaction method. Samples added with different Ta2O5 contents are fabricated and compared in terms of phase structure, microstructure, piezo-/ferro-electric properties, and dielectric relaxation. High piezoelectric properties (d33 = 640 pC/N, d33∗ = 676 p.m./V, Tc = 303 °C) are achieved in the 0.70 wt% Ta2O5 added ceramic with a minimum activation energy of domain wall movement (Ea) of 0.025 eV. Rietveld refinement and Raman spectroscopy show that all the ceramics exhibit rhombohedral-tetragonal (R-T) coexistence and the distortion degree of crystal structures increases with the increase of Ta2O5 content. Our results show that the larger the content of the tetragonal phase (CTP), the lower the Ea, the smaller the domain, and the higher the piezoelectric response. Low Ea favors orientation and extension of polar regions and facilitates the formation of the nanometer-size domain structure (polar nanoregions) which is observed by using piezoresponse force microscopy, thus resulting in high piezoelectric properties. This mechanism associated with the CTP, the Ea and the domain structure reveals the origin of the high piezoelectricity in the low-temperature sintering PZT-based relaxor ferroelectric ceramics.

Copper/Silver Recovery from Photovoltaic Panel Sheet by Electrical Dismantling Method

The volume of spent photovoltaic (PV) panels is expected to grow exponentially in future decades. Substantial material resources such as silver (Ag), copper (Cu), aluminum (Al), silicon (Si), and glass can potentially be recovered from silicon-based PV panels. In this paper, we targeted the recovery of Cu and Ag from a cell sheet separated to a glass panel from a spent PV panel. The technical feasibility of a novel electrical dismantling method was experimentally studied. This method employed a pulsed power technology that releases high energy in a short time. It allowed a selective separation of the Cu/Ag wires from the sheet once per discharge in water. The experimental results indicated that 95.6% of the total Cu and 17.2% of the total Ag in the sample were successfully separated from the cell sheet using a 3.5-kJ capacitor bank circuit. Moreover, 3.66% of the total Si in the sample was contaminated by the separated Cu/Ag particles from the cell sheet, mainly by shockwaves generated by plasma expansion, and some of them formed a compound with Cu and Ag by eutectic melting, resulting in low liberation. At the lower energy of 3.5 kJ, eutectic melting of Cu and Ag with Si was more suppressed than 4.6 kJ, and 94.3% of Cu and 77.5% of Ag in the separated particles were liberated, which would be acceptable for further wet gravity and/or shape separation of Cu and Ag.

SnO2-Ag composites with high thermal cycling stability created by Ag infiltration of 3D ink-extruded SnO2 microlattices

SnO2-Ag composites with designed architectures with sub-millimeter feature sizes can provide enhanced functionality in electrical applications. SnO2-Ag composites consisting of a ceramic SnO2 micro-lattice filled with metallic Ag are created via a hybrid additive manufacturing method. The multistep process includes: (i) 3D extrusion printing of 0/90° cross-ply micro-lattices from SnO2-7%CuO nanoparticle-loaded ink; (ii) thermal treatment in air to burn the binders and sinter struts of the SnO2 micro-lattice to ~94% relative density; (iii) Ag melt infiltration of channels of sintered micro-lattices. Densification of the SnO2 struts during air-sintering is accelerated by CuO liquid phase forming at 1100°C. During the subsequent Ag infiltration, CuO acts as wetting agent between Ag and SnO2, with liquid Ag infiltrating the open channels of the SnO2 lattice and the micropores in the SnO2 struts left from incomplete sintering, thus forming a dense composite. Infiltration time and temperature influence the structure of the SnO2-Ag interface and the distribution of CuO within the Ag matrix. The resulting anisotropic electrical conductivity of the composite is controlled by the low-conductivity SnO2 architecture, as determined via finite element (FE) analysis. 3D ink-extruded and infiltrated SnO2-Ag composites show good structural stability and maintain high conductivity upon thermal shock cycles between 850 and 20°C. FE analysis reveals that thermal expansion/contraction mismatch stresses between the ceramic and metallic phases are mostly concentrated at the contact area between filaments in the SnO2 microlattices, and that plastic deformation accumulating in the soft Ag phase accommodates these mismatch stresses upon thermal cycling.

Properties of Sn‐Ag‐Cu Solder Joints Prepared by Induction Heating

In the present work, one near‐eutectic and three hypoeutectic Sn‐Ag‐Cu alloys have been employed for soldering by induction heating. The alloys were produced by induction melting of high purity Ag, Cu, and Sn lumps. The melting behavior of the alloys was investigated by differential scanning calorimetry. The solder alloys were subsequently applied for soldering by conventional hot‐plate heating as well as induction heating and both soldering times and peak temperatures were recorded during soldering. Solder joints of two copper sheets were produced. The electrical resistance, tensile strength, and microstructure were analyzed on each soldered joint. The results indicate that the physical and mechanical properties of solder joints are determined by their chemical composition and soldering technology. Induction soldered joints not only have a slightly higher electrical resistivity but also higher mechanical strength, except of the 0.3 wt.% Ag hypoeutectic solder. The highest increase in ultimate tensile strength (28%) was observed for induction soldered joints with 1 wt.% Ag hypoeutectic solder. This effect is ascribed to the homogenous distribution of the intermetallic compounds within the eutectic in the alloy microstructure. The homogenous distribution is aided by rotation of liquid solder due to eddy currents and high‐frequency magnetic field generated during induction heating.

Effect of the off-Diagonal d–d Electron Overlappings on the Effective Pair Interaction in the Equiatomic Cu–Ag Melt

The effect of d electron overlapping between two neighboring atoms, which is off-diagonal in magnetic quantum number, on the effective pair interaction in the equiatomic Cu–Ag melt near the melting temperature is studied within the framework of the Wills–Harrison model. An increase in the fraction of off-diagonal overlapping is shown to increase the first minimum depth and to shift its coordinate to smaller interatomic distances for all three partial pair potentials.

Determining high quasi­hydrostatic pressure up to 7 GPa at a temperature to 1,400 °С using resistive sensors

A differential method for measuring high quasi‒hydrostatic pressures for six‒punch pressing installations has been constructed by building a load‒carrying characteristic р=f(Q), where p is the value for pressure in a quasi‒hydrostatic cell of high‒pressure, Q is the force of the press. Pressure in the cell is measured by using the measurement of a temperature difference between the polymorphic transformations into Co(α→β) and Fe(α→γ), melting of Cu and Ag; the measurements are performed by resistometry. The initial data used were the lines of polymorphic transitions in iron (BCC‒FCC) and cobalt (FCC‒HCP) within the ranges p=4‒7 GPa and T=500‒700 °C, examined in detail earlier in the p, T‒diagrams, as well as copper and silver melting curves at p=4‒7 and T=1,150‒1,400 °C.The database of initial data is represented in the analytical form, which has made it possible to use them to determine pressure in the cell at high temperatures based on the values for magnitudes of the differential temperature difference ΔTd, which was measured experimentally for the Coα‒β–Feα‒γ and AgL.–CuL. sensors, designed in the current paper; we have described the features in assembling differential sensors and their electrical connections in order to perform the process of measuring the magnitudes for ΔTd. We have designed structures for the high-pressure cells to conduct experiments on measuring ΔTd using thermocouples and a circuit that registers a change in the resistance of sensors at phase transformations.The procedure applied has made it possible to determine pressure in the quasi-hydrostatic cells of six-punch setups by building load characteristics. The main benefits of the devised method for measuring quasi‒hydrostatic pressures by resistometry are its relative simplicity and a significant increase in the accuracy of pressure determination. The latter is achieved through the mutual elimination of corrections of pressure impact and parasitic components for the magnitude of thermo‒EMF of thermocouples in determining the values for a temperature of phase transformations in the resistive sensors Co‒Fe and Ag‒Cu.The data obtained could be used for monitoring and measuring pressures in the cells of six-punch pressing installations with a plunger diameter of 560‒950 mm.

High‐temperature multilayer actuators based on CuO added BiScO3–PbTiO3 piezoceramics and Ag electrodes

AbstractHigh‐temperature multilayer actuators based on Cu doping 0.367BiScO3–0.633PbTiO3 ceramic slices and Ag electrodes were prepared by low‐temperature co‐firing technology. The 0.3 wt% CuO addition has effectively reduced the sintering temperature of the ceramic from ~1080 to 930°C, thus the multilayer actuator were sintered at 930°C which is lower than the Ag melting point, that is, 961°C. The 4.3 mm thick multilayer actuator is composed of a series of ~44‐μm‐thick ceramic slices and ~2‐μm‐thick Ag electrodes. As a result, a ≥0.13% strain with nm‐scale preciseness can be produced in the actuator by 200 V driving voltage not only at room temperature but also at a high temperature up to 200°C. This actuator is essential for industrial machinery that requires nm‐scale position control at 20‐200°C.