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Doro-e refers to a genre of Japanese folk paintings: it is a group of works, likely to be produced from the mid-eighteenth to the nineteenth century, that emerged during a time when some of the techniques of European paintings, such as vanishing point, perspective, and mirror image were being incorporated into traditional Japanese paintings. Indeed, doro-e paintings played an important role in familiarising the Japanese public with these new techniques. However, the process of painting doro-e including materials and painting techniques used has not been interpreted, and the definition of doro-e remains elusive. This article begins by exploring Kamigata doro-e, particularly megane-e (vue d'optique), which was painted in the initial period of doro-e works. Materials analysis indicates the use of smalt, which is not often found in traditional Japanese paintings. Indigo was also used to depict landscapes, indicating that traditional blue dye was still the preferred colour for European-influenced paintings during the Edo period (1603–1868). This study also discusses the application of gold-coloured outlines identified as brass. A diversity of colourants and techniques was used in doro-e, a fact that is not reflected in the current definition regarding doro-e, and is discussed in this article. [ABSTRACT FROM AUTHOR]

The increasing demands for precision and efficiency in machining processes, driven by advancements in aerospace, biomedical, and automotive industries, have led to a growing need for highly accurate machined parts. Stainless steel 316, a commonly used material in these sectors, presents specific challenges due to its intended applications, particularly in biomedical and aerospace fields. Electric discharge machining (EDM) is a favored method for working with this alloy. However, EDM has inherent challenges, such as dimensional overcuts, which have limited its applicability. To address these issues, the potential of three different electrode materials, namely, copper (Cu), brass, and aluminum (Al), has been extensively explored. Additionally, the choice of the optimal dielectric is crucial as it directly affects the heat input to the electrode, influencing the melting and vaporization of the tool wear. In this context, the inclusion of graphene as an additive has been explored to minimize radial overcuts. It is worth noting that these concerns have not been comprehensively addressed before. The experimental design by Taguchi has been employed for the research, and the results indicate that the performance of the Cu electrode surpasses that of other dielectrics. The artificial intelligence-based artificial neural network (ANN) was constructed to predict the values of OC. It was found that in the given dataset, the R2 has a value greater than 0.99 for all possible training and validation. Based on the ANN, a multi-objective optimization through genetic algorithm (MOGA) was performed. It was found that the dimensional accuracy achieved by Cu electrode was 70.51% better than the highest OC value given by same electrode. Moreover, the OC suggested by the MOGA for brass and Al electrodes was 40.21% and 34.37% better compared to the highest values of radial overcut obtained during the actual experimentation. [ABSTRACT FROM AUTHOR]

Because of its excellent mechanical qualities and weldability, titanium alloy is used in many different biomedical applications. Wire electrical discharge machining may be used to machine materials with such greater strengths and intricate forms. Using Taguchi-data envelopment analysis-based ranking (DEAR) approach and zinc-diffused coated brass wire electrode to improve Titanium alloy machining was the goal of this research project. The quality metrics that were taken into consideration were surface roughness, kerf width, and material removal rate. Among the selected factors, with an error of 2.7%, the optimal configuration of input factors was determined to be 130 µs (Ton), 40 µs (Toff), 50 V (SV), 6 A (IP), and 8 kg (WT). Due to its relevance in the process of deionization, the Ton is the highest influential parameter for creating quality measurements. [ABSTRACT FROM AUTHOR]

The flanging process is widely used in stamping production: when collar drawing small holes for threads or to increase the stiffness of a draw piece. It can also replace the operation of deep drawing cylindrical draw pieces with a large flange followed by cutting the bottom. The paper discusses the influence of the shape of the punch and the grade of material on load changes at various collar drawing coefficients. Flat, spherical and conical punches and samples made of EN-AW 1050A aluminium, Cu-ETP copper, CuZn37 brass, S235JRG2 steel, X6Cr17 steel and X5CrNi18-10 steel were used for testing. The relative thickness of test pieces was 0.015 (which corresponded to a thickness of 1 mm and a blank diameter of 66 mm). Various collar drawing factors ranging from 0.32 to 0.54 were adopted in the studies. An analysis of the obtained height of collars and wall thicknesses was carried out. The experimental tests were carried out using special tooling mounted on a testing machine with a 20 kN load for 0.5 metrological class. Changes in the force as a function of the displacement of the punches were recorded using Test&Motion software that is commonly applied in research laboratories. Based on the obtained results at various technological parameters, possibility of flanging process was evaluated in industrial conditions. [ABSTRACT FROM AUTHOR]

During the production of recycled brass, trace amounts of Fe in the scrap brass stream can accumulate and, upon melting can precipitate and agglomerate in the matrix, which affects the performance of the brass. Microalloying control by adding trace amounts of other elements is expected to mitigate the effect of iron-rich phase agglomeration and improve the mechanical properties of recycled brass. This work added a small amount of Al (0.4–0.8 wt%) to improve the performance of Fe-containing brass (0.6 wt%) in cast and extruded states. It was found that the addition of Al changed the form, morphology, and type of the original Fe-rich precipitated phase. In the metallographic structure, Al was mainly combined with Fe in the matrix to form fine Fe3Al intermediate compounds. The hardness of as-cast brass was harder by the evolution of structure. Adding Al significantly improved the agglomeration behavior of the precipitated phase and enhanced the dispersion distribution characteristics. The reason for dispersion distribution was analyzed, which is the synergistic action of interfacial energy and capillary action energy. The mechanical properties of extruded states under a high extrusion ratio with different contents of Fe–Al microalloying were studied. For the extrusion state, the addition of Al significantly improved the mechanical properties of brass, including tensile and torsional properties. This study can provide a reference for microstructure control and property optimization of recycled brass. [ABSTRACT FROM AUTHOR]

This study undertakes a systematic investigation into the influence of cryogenic rolling (CR) deformation on the microstructure evolution and mechanical properties of low‐density Fe‐28Mn‐8Al‐1C steel. The results reveal that the microstructure undergoes a series of transformations, from equiaxed austenite grains to elongated grains with strain bands, twinning, dislocation entanglements, and dislocation cells. The texture evolves from brass to copper with increasing deformation. Besides, the mechanical properties exhibit a direct correlation with the extent of deformation, as evidenced by the notable increase in ultimate tensile strength, yield strength, and microhardness from 882 to 1861, 505 to 1791 MPa, and 284 to 578 HV, respectively. However, elongation decreases from 64% to 6.6%, indicative of the strength‐ductility trade‐off. The aforementioned findings provide insight into the potential for manipulating the microstructure evolution and mechanical properties of low‐density steels utilizing CR. [ABSTRACT FROM AUTHOR]

The influence of the microstructure of highly confined secondary explosive on the transition to detonation initiated by a thermal solicitation was studied. Three batches of HMX with three orders of magnitude in the granulometry were characterized and compacted in brass tubes to determine their CoDDT distance following a LASER pulse initiation. The post-compaction granulometry was less relevant than the pellets' pore size and the batch initial granulometry which were determinant. A pore size below 200 nm was not sufficient for a transition. The run length was scaled with the inner diameter for porosities higher than 15% for the big grains. [ABSTRACT FROM AUTHOR]

Let n be an odd positive integer. It was proved by Brass and Schmeisser that for every quadrature Q = α 1 f (x 1) + ⋯ + α m f (x m) (with positive weights) of order at least n + 1 and for every n - convex function f, the value of Q on f lies between the values of Gauss-Legendre and Gauss-Lobatto quadratures of order n + 1 calculated for the same function f. We generalize this result in two directions, replacing Q by an integral with respect to a given measure and allowing the number n to any positive integer (for even n Gauss-Radau quadratures replace Gauss-Legendre and Gauss-Lobatto ones). [ABSTRACT FROM AUTHOR]

Aluminium alloys have been one of the leading materials used in aircraft structural components due to their mechanical performance, low density, and different manufacturing and inspection techniques. The mechanical, chemical, and electrical properties of metallic alloys relate to the microstructural arrangement, which depends on the alloying elements and manufacturing parameters. Therefore, this study aims to experimentally develop an Al-2wt.%Ni-0.5wt.%Co alloy as an alternative for aerospace applications, evaluating the main metallurgical aspects influencing mechanical strength. The samples were solidified in brass moulds with four different diameters, allowing four different cooling rates. A statistical analysis of the correlation between microstructural parameters and mechanical properties is proposed to optimise the conditions for obtaining the best mechanical strength. A microstructure with an essentially cellular matrix of the α-Al phase was observed. The tensile strength limit values (σU) of 117 MPa, specific elongation (δ) of 13.8%, and average microhardness of 33 HV were obtained. The Al-2wt.%Ni-0.5wt.%Co alloy exhibits impressive high cycle fatigue performance, with an endurance limit of 91 MPa at 107 cycles, driven by the synergistic effects of Al3Ni for strength and Al9Co2 for enhanced ductility and toughness. [ABSTRACT FROM AUTHOR]

Brass is among the utility metals for daily life. We present an easy corrosion experiment for demonstration in high school or first-year undergraduate studies. Almost any kind of brass can be dezincified in 1 m hydrochloric acid. Copper as the noble component remains as salmon pink coating on the workpiece while zinc and lead, the latter being a frequent minor alloying component of brass, are dissolved. Lead can be detected as PbS (in-situ generation of H2S from a splinter of FeS or as PbI2 using KI). Zinc can be analyzed as Rinmann's green or via a microchemical drop reaction with dithizone. [ABSTRACT FROM AUTHOR]

The exploration of unleaded free-cutting Cu40Zn brass with excellent mechanical and tribological properties has always drawn the attention of researchers. Due to its attractive properties combining metals and ceramics, Ti3AlC2 was added to Cu40Zn brass using high-energy milling and hot-pressing sintering. The effects of Ti3AlC2 on the microstructure, mechanical and tribological properties of Cu40Zn-Ti3AlC2 composites were studied. The results showed that Ti3AlC2 could suppress the formation of ZnO by adsorbing oxygen impurity and promote the formation of the β phase by releasing the β-forming element Al to the substrate. The hardness and wear resistance of Cu40Zn-Ti3AlC2 composites increased with increasing Ti3AlC2 content from 0 to 5 wt.%. The proper Ti3AlC2 additive was beneficial to both the strength and plasticity of the composites. The underlying mechanisms were discussed. [ABSTRACT FROM AUTHOR]

The purpose of this study is to develop brass based composites using friction stir processing (FSP) for improved wear resistance. SiC particles (volume percentage of 0–18) were efficiently reinforced into Cu−40Zn dual phase brass using FSP. A tool rotational speed of 1600 rpm and a traverse speed of 60 mm/min were used. The FSP process provided an excellent distribution of SiC particles without aggression and segregation. The solid state processing subdued the role of density gradient to have an adverse effect on particle distribution. EBSD maps demonstrated extreme refinement of grains because of dynamic recrystallisation. TEM micrographs hinted that the dynamic recrystallisation was interrupted i.e. discontinuous. Few dislocation fields as well as twinned grains were spotted. SiC particles were beneficial to improve the resistance to wear of the brass composite. Further, the role of SiC particles on the mode of sliding wear as well as the size of wear debris was reported. [ABSTRACT FROM AUTHOR]

Salinity affects greatly cultivated land by reducing its fertility; also it can lead to potential damages to substructures or even conduct to a collapse in the long run by changing soil geotechnical properties. Electrokinetic technology (EKR) is a promising technique for removing salinity from low-permeability soils. For these, it is essential to study the parameters that govern electro osmotic permeability in order to predict effectiveness and optimize electrokinetic treatment. This work concerns the application of the (EKR) method on the saline-sodic soil of the Bordjias plain located in the south-western region of Mostaganem (Algeria). Due to the semi-arid climate prevailing in this region, vast tracts of land are currently being lost due to salinization. The efficiency of this method is studied by the variation of the electric voltage gradient (0.375, 0.50, and 0.625 V/cm) surface and the electrode materials (brass and copper) on electro-osmotic permeability and electrical energy consumption. The results showed that increasing the electric voltage gradient had no effect on the intensity of electrolysis reactions, which did not change beyond a specific limit, and did not increase the electroosmotic flow; but it generated more electric current than the admissible current for copper electrodes, causing corrosion, unlike brass electrodes, which resisted significantly. For the same electric voltage gradient, brass electrodes resisted longer and resulted in a higher flow rate than copper. Maximum electroosmotic flow was recorded at 0.5 (V/cm) voltage gradient for both material electrodes, but the highest volume of flow evacuated was recorded for EKB2 (brass) (GR2) tests. The coefficient of electroosmotic permeability is inversely proportional to the electrical gradient in contrast to the electrical energy consumption which is also influenced by the type of electrode material used. This implies that an increased voltage gradient results in higher current and energy consumption. The study revealed no significant difference in energy consumption between brass and copper materials in terms of value; however, the Brass exhibits greater durability compared to copper materials. The conducted tests lead to the conclusion that the efficiency of the process can be achieved at a lower applied voltage, using a brass electrode for soils with high salinity concentrations. Consequently, an appropriate electric voltage gradient needs to be determined to achieve efficient electroosmotic treatment while effectively reducing the corresponding energy consumption. [ABSTRACT FROM AUTHOR]

The production and characterization of UNS C65620 (CuZn3Fe2Si3) and UNS C87800 (CuZn15Si4) coded alloys were investigated. The alloys poured into the gravity die casting method were hot forged with a ram, followed by stress relief annealing heat treatment. While the formation of Cu4Si, Cu0.83Si0.17 and Cu5Zn8 phases were detected in the structure of the UNS C65620 coded alloy, Cu12.75SiZn2.92 and Cu3Zn intermetallics with the phases given above were observed in the structure of the alloy containing more Zn and Si. The formation of phases containing more Si and Zn resulted in an increase in both the hardness and strength of the UNS C87800 coded alloy, while the decrease in the % reduction of area and the observation of dynamic deformation aging caused the increase in both the wear rate and deformation hardening rate, which led to embrittlement of the alloy. The deterioration of the corrosion resistance of the UNS C87800 coded alloy can be attributed to the formation of Zn-rich corrosion products on the surface during corrosion.

Lacquered brass objects are widely present in scientific and technical heritage collections. Localized atmospheric corrosion occurs on the metal when the coating fails to play its protective role. Although lacquered brass objects are not necessarily endangered by this phenomenon, the presence of dark, unpleasant corrosion spots alters the surface appearance, affecting the readability of the objects. Conservators are therefore frequently asked to clean these surfaces. We hereby present the results of a study conducted in the framework of the CleanLaB (Cleaning of Lacquered Brass) project at the Haute Ecole Arc of Neuchâtel for the cleaning of lacquered brass. This work investigates the effects of several gelled cleaning systems applied on artificially aged, lacquered brass samples to remove the corrosion products without affecting the integrity of the coating. The performance of complexing agents commonly used in conservation was compared on lacquered brass mock-ups coated with shellac resin by means of multiple non-invasive characterization and imaging techniques. The tests included conventional complexing agents like sodium citrate and disodium ethylenediaminetetraacetic acid, as well as a bio-originated system based on deferoxamine, a microbial metal chelator investigated as a green alternative in cleaning formulations.

The existence of striations, and scratches in Abrasive waterjet (AWJ) cutting surface necessitates an exploration of these features for enhancing the cutting accuracy of AWJ machining. This article investigates surface roughness and micro-scratch morphology characteristics on brass cutting surfaces. According to the variation law of surface roughness values, the cutting section can be divided into three regions: the initial region, smooth region, and rough region. Numerous micron-scale scratches were observed in the cutting section. The scratch length, width, and depth values all show an increasing trend as the cutting depth increases, with the scratch length experiencing the greatest growth and variability. The influence of position and traverse speed on scratch size was studied using variance analysis. Furthermore, the length and width of the scratches on the cutting surface are significantly influenced by their position, accounting for 89.19% and 81.13%, respectively. Traverse speed had a minor effect on scratch length and width, accounting for 0.01% and 2.64% respectively. The depth of the scratches is influenced by their position on the cutting surface at a rate of 41.12%, while traverse speed had an impact of 38.10%. Finally, a mathematical method based on standard scores was proposed to assess the quality of the cutting section based on micro-scratch dimension. [ABSTRACT FROM AUTHOR]

Similar to conventional blanking, there are some characteristics, such as rollover, burnish, and fracture on the sides of micro blanked parts, and rollover height and fracture height vary with the blanking clearance. This paper attempts to reveal the effect of blanking clearance on the rollover height. An uncoupled ductile fracture criterion is used to describe the effect of the blanking clearance on the fracture height. The experimental and simulation results show that the increase in hydrostatic stress gradient on the foil around the die edge results in an increase in rollover height. The coefficients of the uncoupled ductile fracture criterion are determined by the method of inverse solution and data fitting. The criterion is evaluated by mean-square error to ensure its validity. This analysis method has been verified by micro brass blanked part. [ABSTRACT FROM AUTHOR]

Information on the flyer deformation during laser impact welding (LIW) is an important aspect to consider when high reliability of the welded components is required. For this reason, accurate numerical models simulating thermal and mechanical aspects are needed. In the present work, the cross-section morphology during LIW of Ti/Brass joints at varying laser pulse energies is modeled by a 2D finite element (FE) model. A hydrodynamic plasma pressure model able to describe the evolution of the pressure load step by step, taking into account the progressive deformation of the flyer, was implemented. Hence, this paper proposes an alternative method to the conventional node concentrated forces or predefined velocity as flyer boundary conditions. The levels of the equivalent plastic strain (PEEQ), shear stress, and critical flyer velocity at the collision point were used as reference parameters to predict the success of the welding bond, distinguishing the welded area from the unwelded area. The model was validated by comparison with the experimental data, which showed the effectiveness of the proposed FE code in predicting the cross-section morphology of the welded materials. Moreover, practical industrial information such as variation in the flyer impact velocity, collision angle, and process temperatures was predicted by varying the process laser pulse energy according to the basic principle of the process. [ABSTRACT FROM AUTHOR]

The current research investigates the effects of materials and riblets on cavitation-induced erosion morphology, depth, and cross-sectional area through experimental approaches. To achieve these aims, the erosion of pure aluminum (1xxxAl or Al) and alpha brass (CuZn37 or CZ108), in the presence and absence of bio-inspired sawtooth riblets, was examined after exposure to multiple collapses of single cavitation bubbles with a wall distance of 1.8 (dimensionless). The results indicate that the erosion morphology resembles a rounded cone with a circular cross-section. Brass provides 21.6% more erosion resistance compared to that of Al in terms of material properties. Furthermore, the erosion for both Al (depth by 3.8% and width by 18.3%) and brass (depth by 7.9% and width by 27.4%) decreases in the presence of riblets compared to the results for flat surfaces. The greater erosion resistance of brass compared to Al is attributed to the superior mechanical stability of brass, making it a potentially suitable alloy for use in propellers and hulls in the shipping industry. In summary, the results reveal that riblet-equipped materials with high mechanical durability are promising erosion-resistant materials for the shipping industry. However, the potential for chemical reactions in a cathodic environment should be addressed to provide a comprehensive perspective in regards to reducing corrosion intensity. [ABSTRACT FROM AUTHOR]

PEO coatings are formed by subjecting a metal substrate to an electrolytic plasma discharge, resulting in the formation of a porous and rough oxide layer. Herein, the significant role of the chemical composition of the electrolyte system and additives in the formation of an oxide coating on brass alloy in the PEO process was investigated. It was observed that the coating created with 8 g/l aluminate, 1 g/l NaOH, and 1 g/l KF electrolyte had higher homogeneity than other coatings. This is because a composite oxide coating of Cu 2 O, ZnO, and AlCuO 2 was formed. Methylene Blue (MB), a widely used dye in various industries, is known to be persistent and environmentally harmful. The photocatalytic activity of the PEO coating on brass for the removal of MB was investigated under visible light exposure. According to the results, the presence of the sample produced in an electrolyte containing 8 g/l Aluminate, 1 g/l NaOH, and 1 g/l KF resulted in a degradation rate of approximately 65 % for MB photodegradation after 6 h of irradiation. The PEO-coated brass shows promising photocatalytic efficiency compared to our research group's PEO-coated TiO 2 coatings, indicating its potential as a photocatalyst. The results highlight that PEO coating on brass could be a potential candidate for photocatalytic and photoelectrochemical applications. [ABSTRACT FROM AUTHOR]

The production and characterization of UNS C65620 (CuZn3Fe2Si3) and UNS C87800 (CuZn15Si4) coded alloys were investigated. The alloys poured into the gravity die casting method were hot forged with a ram, followed by stress relief annealing heat treatment. While the formation of Cu4Si, Cu0.83Si0.17 and Cu5Zn8 phases were detected in the structure of the UNS C65620 coded alloy, Cu12.75SiZn2.92 and Cu3Zn intermetallics with the phases given above were observed in the structure of the alloy containing more Zn and Si. The formation of phases containing more Si and Zn resulted in an increase in both the hardness and strength of the UNS C87800 coded alloy, while the decrease in the % reduction of area and the observation of dynamic deformation aging caused the increase in both the wear rate and deformation hardening rate, which led to embrittlement of the alloy. The deterioration of the corrosion resistance of the UNS C87800 coded alloy can be attributed to the formation of Zn-rich corrosion products on the surface during corrosion. [ABSTRACT FROM AUTHOR]

This research develops and validates a low-cost, simple hydraulic bulge test device designed to characterize the formability of thin metal foils under pure biaxial strain conditions. The study focuses on yellow brass foil (Cu-Zn) with a thickness of 0.2 mm, using a device with a small bulge diameter (20 mm), relevant for mini-forming applications. The collected data includes the relationship between pressure and bulge height, which is then converted into effective stress and effective strain. This device aims to directly generate stress-strain data for calculating the strain hardening exponent (n-value). Key innovations include the use of a small bulge diameter suitable for mini-forming and the application of circular markers on the specimen surface to facilitate the conversion of pressure-height data into stress-strain parameters. Validation results show that the device accurately measures the pressure vs. bulge height relationship. While initial data demonstrates accuracy in measuring pressure and bulge height, additional methods are required to directly convert these measurements into effective stress and strain parameters.This research provides an economical solution for material characterization in mini-forming applications and presents a reliable tool for further studies on various types of thin metal foils. [ABSTRACT FROM AUTHOR]

The relationship between acoustic parameters and the microstructure of a Cu30Zn brass plate subjected to plastic deformation was evaluated. The plate, previously annealed at 550 °C for 30 min, was cold rolled to reductions ranging from 10% to 70%. Linear ultrasonic measurements were performed on each of the nine specimens, corresponding to the nine different reductions, using the pulse-echo method to record the times of flight of longitudinal waves along the thickness axis. Subsequently, acoustic measurements were conducted to determine the nonlinear parameter β through second harmonic generation. Microstructural analysis, carried out by X-ray diffraction, Vickers hardness testing, and optical microscopy, revealed an increase in deformation twins, reaching a maximum at 40% thickness reduction. At higher deformations, the microstructure showed the generation and proliferation of shear bands, coinciding with a decrease in the twinning structure and an increase in dislocation density. The longitudinal wave velocity exhibited a 0.9% decrease at 20% deformation, attributed to dislocations and initial twin formation, followed by a continuous increase up to 2% beyond this point, resulting from the combined effects of twinning and shear banding. The nonlinear parameter β displayed a notable maximum, approximately one order of magnitude greater than its original value, at 40% deformation. This peak correlates with a roughly tenfold increase in twinning fault probability at the same deformation level. [ABSTRACT FROM AUTHOR]

Interest in recovering DNA from the surface of ammunition evidence for genotyping has increased over the past few years. Numerous studies have examined a variety of methods to maximize DNA recovery from these types of challenging samples, but successful DNA profiling has been inconsistent. Low amounts of DNA and PCR inhibition due to metal ions have been suggested as the leading causes of poor results; however, no study quantitatively examined the presence of metal ions at various stages of the DNA analysis workflow from DNA collection through to amplification. In this study, the effectiveness of six different DNA collection and purification methods commonly used by forensic laboratories to process brass ammunition for DNA evidence was investigated. The amount of copper, zinc, and other metals co-recovered from fired and unfired brass casings during DNA collection (using numerous soaking, swabbing, and direct PCR protocols) was quantified via Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). This same panel of metals was subsequently quantified after DNA lysis and purification steps. Results demonstrated that low amounts of DNA, DNA damage, and degradation are more detrimental to STR typing results than PCR inhibition, as metal ions were successfully removed by all DNA purification methods tested. Furthermore, the use of metal ion chelators increased the amount of DNA recovered and number of reportable STR alleles. This research informs the forensic community on the most effective way to collect and process trace amounts of biological material from brass ammunition and similar evidence. [ABSTRACT FROM AUTHOR]

The corrosion inhibition performance of air nanobubbles (A‐NBs) is expected to address the environmental problems arising from chemical corrosion. In order to regulate the corrosion inhibition performance of A‐NBs, the particle characteristics of A‐NBs in flowing composite salt solutions are investigated, and the corrosion inhibition effect of A‐NBs under different concentration ratios and rotational speed of simulated circulating cooling water is studied. High salt concentrations significantly reduced the particle size, concentration, and zeta‐potential value of A‐NBs, thus reducing the stability of A‐NBs. The flow velocity has a slight effect on A‐NBs. The results of the weight loss and electrochemical method showed that A‐NBs achieved the highest corrosion inhibition rate of 55% under a concentration ratio of 1.5 and a rotational speed of 100 r min−1. The surface characterization of brass specimens revealed that A‐NBs facilitated the formation of Cu2(OH)2CO3 passivation film, calcium carbonate scale film, and a layer of bubbles on the surface of brass, which subsequently mitigated the erosive impact of the fluid. A‐NBs can adsorb cations and thus reduce the concentration of corrosive ions. However, the increase in concentration ratio and rotational speed impeded the formation of the bubble layer and passivation film. [ABSTRACT FROM AUTHOR]

Free-cutting brass is a material whose machinability is improved by the addition of lead. It is used in a wide range of applications because of its high electrical conductivity and antibacterial properties. However, the use of lead is restricted by laws and regulations to reduce environmental damage. Therefore, the lead in free-cutting brass is being replaced by bismuth or silicon. The machinability of lead-free brass, improved by these additives, has been confirmed to be sufficient for milling and turning. However, when drilling deep small-diameter holes in leadless brass, the problem of premature drill breakage occurs due to chips clumping and clogging in the drill flutes. In a previous study, drilling of holes with an aspect ratio of nine was performed using a 1.0 mm diameter cemented carbide drill, and it was confirmed that the addition of trace elements improved the chip breaking and chip evacuation. However, the waveform of thrust force during machining demonstrated a decreasing trend, and the original machining conditions were not attained. In this study, the effect of feed rate on chip evacuation was investigated using a 0.5 mm diameter twist drill, which is subject to severe chip evacuation at high cutting speeds. As a result of examining chip evacuation by varying the feed rate, the chip evacuation exhibited good performance; where bellows-like chips were evacuated under a slow feed rate, and long-pitch chips were evacuated under a high feed rate. In the drilling process using these feed rates with good chip evacuation, 10,000 holes could be drilled, but the shape of the top of the hole was distorted and the straightness was poor at a slow feed rate. In contrast, hole accuracy was good at a high feed rate, further indicating that a high feed rate with long-pitch-shaped chip evacuation is effective for high efficiency when drilling deep holes of small diameters. [ABSTRACT FROM AUTHOR]

Copyright of Studia Academica Šumenensia is the property of Konstantin Preslavsky University of Shumen and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Studia Academica Šumenensia is the property of Konstantin Preslavsky University of Shumen and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve the machinability properties of CuZn-alloys, these are alloyed with the element lead. Due to its toxicity, a variety of legislative initiatives aim to reduce the lead content in CuZn-alloys, which results in critical machinability problems and a reduction in the productivity of machining processes. Basically, there are two ways to solve the critical machinability problems when machining lead-free CuZn-alloys: optimizing the machinability of lead-free materials on the material side or adapting the processes and the respective process parameters. In this study, the focus is on material-side machinability optimization by investigating the influence of a targeted variation in the process chain in the material production route. To evaluate the influence of the material production route, the brass alloy CuZn40 (CW509L) was produced in four variants by varying the degree of work hardening and the use of heat treatments, and all four variants were evaluated in terms of their machinability. To evaluate the machinability, the cutting force components, the chip temperature, the chip formation, and the chip shape were analyzed. Clear influences of the material production route were identified, particularly with regard to the chip formation mechanisms and the resulting chip shape. [ABSTRACT FROM AUTHOR]

Copper-containing materials are attracting attention as self-disinfecting surfaces, suitable for helping healthcare settings in reducing healthcare-associated infections. However, the impact of repeated exposure to disinfectants frequently used in biocleaning protocols on their antibacterial activity remains insufficiently characterized. This study aimed at evaluating the antibacterial efficiency of copper (positive control), a brass alloy (AB+®) and stainless steel (negative control) after repeated exposure to a quaternary ammonium compound and/or a mix of peracetic acid/hydrogen peroxide routinely used in healthcare settings. A panel of six antibiotic-resistant strains (clinical isolates) was selected for this assessment. After a short (5 min) exposure time, the copper and brass materials retained significantly better antibacterial efficiencies than stainless steel, regardless of the bacterial strain or disinfectant treatment considered. Moreover, post treatment with both disinfectant products, copper-containing materials still reached similar levels of antibacterial efficiency to those obtained before treatment. Antibiotic resistance mechanisms such as efflux pump overexpression did not impair the antibacterial efficiency of copper-containing materials, nor did the presence of one or several genes related to copper homeostasis/resistance. In light of these results, surfaces made out of copper and brass remain interesting tools in the fight against the dissemination of antibiotic-resistant strains that might cause healthcare-associated infections. [ABSTRACT FROM AUTHOR]

Copyright of Stratum Plus Journal is the property of P.P. Stratum plus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A facile method for preparing superhydrophobic brass mesh is proposed based on electrochemical etching and surface modification. The impact of processing time and the electric potential of the electrochemical etching were studied on the contact angle (CA) of the mesh. The samples were examined using scanning electron microscopy, Energy-dispersive X-ray spectroscopy analysis, X-ray diffraction, and Fourier-transform infrared spectroscopy. The electrochemical etching process caused the decrement of wires' thickness and imposed roughness. Results showed more dissolution of zinc than copper under 3 V of the electric potential and the processing times of 3 and 6 min. The optimum condition of electrochemical etching was obtained under the electric voltage of 3 V for a processing time of 6 min, which led to a CA of 155.5 ± 3.2°. The thickness of the mesh wires decreased by 17.7% due to electrochemical etching in this sample. This sample also showed low adhesion for a water drop. The efficiency of oil/water separation was above 95 for the xylene and ethyl acetate in a batch system. The effect of the flow rate of the oil–water mixture on separation efficiency was also examined. The optimum flow rate was 0.8 ml s−1 with a high separation efficiency of 96.8% for xylene/oil separation. [ABSTRACT FROM AUTHOR]

Lacquered brass objects are widely present in scientific and technical heritage collections. Localized atmospheric corrosion occurs on the metal when the coating fails to play its protective role. Although lacquered brass objects are not necessarily endangered by this phenomenon, the presence of dark, unpleasant corrosion spots alters the surface appearance, affecting the readability of the objects. Conservators are therefore frequently asked to clean these surfaces. We hereby present the results of a study conducted in the framework of the CleanLaB (Cleaning of Lacquered Brass) project at the Haute Ecole Arc of Neuchâtel for the cleaning of lacquered brass. This work investigates the effects of several gelled cleaning systems applied on artificially aged, lacquered brass samples to remove the corrosion products without affecting the integrity of the coating. The performance of complexing agents commonly used in conservation was compared on lacquered brass mock-ups coated with shellac resin by means of multiple non-invasive characterization and imaging techniques. The tests included conventional complexing agents like sodium citrate and disodium ethylenediaminetetraacetic acid, as well as a bio-originated system based on deferoxamine, a microbial metal chelator investigated as a green alternative in cleaning formulations. [ABSTRACT FROM AUTHOR]

Low friction and high wear resistance are critical properties for sliding bearings. In this research, advanced Cu/GO nanocomposite coatings have been developed by a brush plating method to improve the tribological performance of brass-based sliding bearings. A series of brush plating studies under voltages from 2 to 6 V with different GO concentrations (0.2–0.8 g/L) was conducted, and the coating microstructures were characterised by SEM, EDX, GDOES and XRD and the tribological behaviour of the Cu/GO composite coatings were evaluated using dry ball-on-plane tribological tests The experimental results have demonstrated that GO can be successfully introduced into the whole composite coating layer; the Cu/GO composite coatings can reduce the friction of brass and increase its wear resistance by two orders of magnitude, mainly due to the self-lubricating GO added into the coatings. [ABSTRACT FROM AUTHOR]

Phase equilibria were investigated between 200 and 800 °C in the Cu-Zn binary system. Wavelength dispersive spectroscopy (WDS) was performed to determine the equilibrium compositions, and differential scanning calorimetry (DSC) was performed to investigate the solidus and liquidus temperatures and the invariant reaction temperatures of the Zn-rich portion. The β/(α + β) boundary in the Cu-rich portion extended toward the Cu-rich side as the temperature decreased below the A2–B2 order–disorder transformation temperature, and the phase boundaries of the γ, δ and ε phases shifted toward the Cu-rich side. The liquidus temperatures of the ε + liquid were higher than those of the previous report. From the experimental results, the phase diagram of the Cu-Zn binary system was determined in the whole composition range. [ABSTRACT FROM AUTHOR]

Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) is successfully employed to determine the chemical composition of brass samples using the LIBS technique. The sample is irradiated with a Q-switched Nd: YAG laser with a pulse width of 5 ns to generate laser-induced plasma (LIP) on the sample surface. The time evolution spectra were recorded from the surface of the brass sample only with an accumulation of five laser shots to get one LIP spectrum. Time-resolved LIP spectra have been utilized to identify the most appropriate time window (where the plasma is optically thin and in local thermal equilibrium) suitable for CF-LIBS implementation. Stoichiometric ablation is also demonstrated for metallic brass samples with the aforementioned laser in the present study. To obtain definitive quantitative information from LIP, the characterization of the plasma, i.e., spectral line intensity, spectral line broadening, electron number density, and plasma temperature, has been analyzed in this paper. Based on two different CF-LIBS algorithms, the brass sample composition was determined and found to be in good agreement with the certified results. This paper also compares and contrasts both strategies, as well as discusses their place and importance. The results of the present manuscript illustrate the potential applicability of CF-LIBS for yielding precise and accurate compositions of brass. [ABSTRACT FROM AUTHOR]

Generally, brazing is completed when the brazing filler metal permeates the gap by uniform wetting. It is believed that the joining process is completed with the formation of joint defects 'voids' in the process of uniform wetting. However, previous studies have shown that what occurs when brazing is performed is non-uniform wetting. It is suggested that this non-uniform wetting is the cause of void generation. Wetting and spreading of brazing filler metal is tested on a metal plate, as described in JIS Z 3191. This is used to investigate the wetting of the brazing filler metal. However, this method does not cover the wetting of the molten brazing filler metal as it moves into the gap. Therefore, it is suggested that the JIS Z 3191 experiment is insufficient to evaluate the wetting of the molten brazing filler metal that penetrates into the gap. In this experiment, we created new specimen. It is called us 'V-groove specimen'. Specimens were created with two base metals. They are pure copper and lead-free brass in which bismuth was used as an alternative element. In order to do in situ experiments, it was not possible to observe the inside of a conventional electric furnace. Therefore, we produced a furnace with a window for in-situ observation and experimented with it. As a result of experiments with V-groove specimens, it was found that there are two types of wetting of brazing filler metal. They are called 'primary wetting' and 'secondary wetting'. The shape of the specimen was measured and evaluated for two types of wetting. The results showed that the primary wetting was measurable in shape and spread evenly. However, the shape of the secondary wetting could not be measured, and it was found to be non-uniformly spread. [ABSTRACT FROM AUTHOR]

Changing the morphology of intermetallic inclusions of two-phase alloyed brass is studied during its heating in a hot deformation temperature range. During heating, the redistribution of elements between silicide inclusions and matrix solution is found to occur, which, in a temperature range of 750–830°С, results in the silicide surface exfoliation and loss of coherence. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the response and local buckling of locally sharp-notched C2700 brass circular tubes (LSN C2700 brass circular tubes) under cyclic bending loads. The study considers four different notch orientations (0°, 30°, 60°, and 90°) and five distinct notch depths (0.2, 0.4, 0.6, 0.8, and 1.0 mm). The results reveal that notch orientation and depth exert minimal impact on the moment–curvature relationship, leading to the formation of stable loops. The ovalization–curvature graphs demonstrate a trend of symmetry, serration, and growth with an increasing number of bending cycles. Additionally, larger notch orientations or smaller notch depths result in reduced ovalization. Furthermore, the double logarithmic coordinates of controlled curvature–number of cycles necessary to induce local buckling reveal five non-parallel lines representing different notch depths when the notch orientation is fixed. Finally, by adopting the formulas for smooth tubes and for locally sharp-notched 304 stainless steel circular tubes (LSN SS304 circular tubes), this study adjusts the related material parameters accordingly. These modifications effectively describe the controlled curvature–number of cycles necessary to induce local buckling for LSN C2700 brass circular tubes with different notch orientations and depths under cyclic bending, demonstrating reasonable agreement with the experimental results. [ABSTRACT FROM AUTHOR]

In the current work, a novel medium entropy copper alloy was designed with the aim of avoiding the use of expensive, hazardous or scarce alloying elements and instead employing widely available and cost-effective alternatives. In order to investigate this unknown region of multicomponent alloy compositions, the thermo-physical parameters were calculated and the CALPHAD method was utilized. This led to the design of the Cu50Zn25Al20Sn5 at. % (Cu53.45Zn27.49Al9.08Sn9.98 wt. %) alloy with a relatively low density of 6.86 g/cm3 compared with conventional brasses. The designed alloy was manufactured through vacuum induction melting, producing two ingots weighing 1.2 kg each, which were subjected to a series of heat treatments. The microstructural evolution of the alloy in the as-cast and heat-treated conditions was assessed through optical and scanning electron microscopy. The hardness of the as-cast and heat-treated alloy at room temperature was also studied. The alloy was characterized by a multiphase microstructure containing a major Cu-rich (Cu–Zn–Al) matrix reinforced with a secondary Zn-rich (Zn–Cu) phase and pure Sn. In terms of mechanical properties, the developed alloy exhibited high hardness values of roughly 378 HV0.2 and 499 HV0.2 in the as-cast and heat-treated conditions, respectively. [ABSTRACT FROM AUTHOR]

This work deals with enhancing piezoelectric energy harvesting by incorporating different auxetic structures and varying geometrical parameters. A bimorph consisting of polyvinylidene fluoride as a piezoelectric layer and brass auxetic substrate (re-entrant, s-shape, and elliptical holes) are considered for analysis. A finite element method-based simulation is performed to find the best auxetic systems that provide higher power output. The environmental vibration is taken for energy harvesting; thus, the first resonance frequency is below 100 Hz. The maximum power of ∼0.52, ∼0.67, and ∼0.79 mW is estimated for piezoelectric energy harvesters (PEH's) re-entrant, s-shape, and elliptical holes. The auxetic re-entrant, s-shape, and elliptical substrate-based PEHs show 200%, 300%, and 333% more power than the solid substrate (conventional design). However, the elliptical-based auxetic structure obtains a maximum power density of 0.004 66 mW/mm3. The stresses in all structures are within the permissible limit; hence, any design can be used for practical applications. All three auxetics have comparable geometrical dimensions and the same material is used; thus, auxetic behavior is independent of the material employed and depends on the structure's shape. The estimated power is higher than that reported in the literature. [ABSTRACT FROM AUTHOR]