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Studies on load capacity enhancement for an interference fit mainly focused on the essential coupling material pair of steel–steel parts. With more complex requirements in technical assemblies, more notable cases of material pairs are applied in interference fits. Hence, it is crucial to highlight the variations across-coupling scenarios in order to identify a workable approach for load capacity augmentation. The goal of this study is to examine how nickel plating affects the interference fit between steel and brass assembly parts. The experiments in this research focus on comparing the load capacity of plated and non-plated specimens by evaluating the extraction force on a compression machine. The fit parameters are measured with a coordinate measuring machine and contact surface profiler. Some microscopic observations are made to confirm the phenomena of this coupling case. The axial extraction tests determined that the plated fits show an increase in axial force limits of around 20% in comparison with the non-plated ones. There are also some significant improvements in the plated shaft surface properties, which reduce the physical adhesions between the shaft and hub. These results confirm the possibility of reusing the plated assembly parts, which gives highly economic and environmental advantages. [ABSTRACT FROM AUTHOR]

Cryptocaryon irritans cause massive losses in the mariculture industry and are among the most threatening pathogens affecting teleost species. Copper‑zinc alloy (CZA) surface contact effectively kills C. irritans within minutes. Thus, this study employed integrated metabolomics and proteomics analysis to investigate the killing mechanism of CZA against C. irritans. Moreover, malondialdehyde contents, CuZn-SOD, and ATPase activities were evaluated. Proteomics analysis identified 142 differentially expressed proteins (DEPs), including 91 (59 upregulated, 32 downregulated), 92 (42 upregulated, 50 downregulated), and 43 (17 upregulated, 26 downregulated) DEPs at 0.5 h, 1 h, and 0.5 h vs 1 h of contact treatment with the CZA surface, respectively. Similarly, the metabolomic analysis identified 377 differentially expressed metabolites (DEMs). There were 237 (94 upregulated, 143 downregulated), 264 (112 upregulated, 152 downregulated), and 193 (101 upregulated, 92 downregulated) DEMs at 0.5 h, 1 h, and 0.5 h vs 1 h of contact treatment with the CZA surface, respectively. KEGG-based integrative analyses revealed that CZA exposure significantly enriched proteins and metabolites involved in oxidative phosphorylation, purine, pyrimidine, cysteine, and methionine metabolism. Notably, CZA exposure inhibited the TCA cycle, disrupting energy metabolism, as evidenced by downregulation of key TCA proteins, including citrate synthase and malate dehydrogenase, and metabolites like succinic and malic acids at both 0.5 h and 1 h of CZA treatment. Prolonged CZA exposure also affected protein metabolism, with significant downregulation of ribosomal protein S3a (RPS3a) and proteasome activity. Additionally, CZA surface contact downregulated key proteins involved in pyrimidine (DHFR-TS), purine (RRM1), and cysteine and methionine metabolism (AHCY), leading to disturbances in the methionine cycle, suppression of glutathione metabolism, and alterations in cellular redox status. Quantitative polymerase chain reaction (qPCR) analysis confirmed the upregulation of citrate synthase, proteasome subunit alpha type, and adenosylhomocysteinase with prolonged CZA exposure. Additionally, extended CZA exposure significantly decreased the MDA content due to the increased CuZn-SOD activity. Moreover, CZA exposure reduced Ca2+/Mg2+-ATPase and Na+/K+-ATPase activities. Altogether, CZA surface contact caused metabolic disruption, lipid peroxidation, and osmotic imbalance of C. irritans tomonts, highlighting the broad molecular impact of CZA on cellular processes. [Display omitted] • Metal copper, zinc, and alloy (CZA) effectively kill C. irritans. • Integrated metabolomics and proteomics analysis evaluated the CZA-killing mechanism against C. irritans. • CZA treatment inhibited the TCA cycle, disrupting energy metabolism. • CZA surface contact caused metabolic disruption, lipid peroxidation, and osmotic imbalance in C. irritans tomonts. [ABSTRACT FROM AUTHOR]

Studies on load capacity enhancement for an interference fit mainly focused on the essential coupling material pair of steel–steel parts. With more complex requirements in technical assemblies, more notable cases of material pairs are applied in interference fits. Hence, it is crucial to highlight the variations across-coupling scenarios in order to identify a workable approach for load capacity augmentation. The goal of this study is to examine how nickel plating affects the interference fit between steel and brass assembly parts. The experiments in this research focus on comparing the load capacity of plated and non-plated specimens by evaluating the extraction force on a compression machine. The fit parameters are measured with a coordinate measuring machine and contact surface profiler. Some microscopic observations are made to confirm the phenomena of this coupling case. The axial extraction tests determined that the plated fits show an increase in axial force limits of around 20% in comparison with the non-plated ones. There are also some significant improvements in the plated shaft surface properties, which reduce the physical adhesions between the shaft and hub. These results confirm the possibility of reusing the plated assembly parts, which gives highly economic and environmental advantages.

Lithium metal batteries (LMB) have been considered as the most promising energy storage devices for electric vehicles and portable electronic devices, however their applications are usually limited due to the poor cycle stability and serious safety problems of the battery, which were caused by uncontrolled growth of lithium dendrite and unlimited volume change of anode during Li plating/stripping. Herein, we design a three‐dimensional porous copper‐zinc alloy (3D Cu−Zn) by powder metallurgy method, which has suitable and controllable porous structure for lithium deposition in lithium metal battery. By systematically tailoring particle size of metal powder and other parameters, the 3D Cu−Zn was prepared, which can be used as current collector of lithium anode and shows good cyclic stability. The Li metal anode with 3D Cu−Zn porous current collector can stably cycle for as long as 800 h under a high Li plating/stripping capacity of 1 mA h cm−2 and high current density of 1 mA cm−2. Li@3D Cu−Zn||LiFePO4 cell has excellent rate performance and cycle performance. This work may open a new avenue for building better lithium metal battery with long cycle performance. [ABSTRACT FROM AUTHOR]

The study determined the kinetics of the selective anodic dissolution of the copper-zinc intermetallic compound Cu5Zn8 (gamma-phase) in an acetate buffer solution. Microscopic and X-ray analysis methods demonstrated the selective nature of the corrosive dissolution of Cu5Zn8. The dissolution results in the dezincification of the intermetalic compound and morphological development of its surface accompanied by the formation of the copper phase. A theoretical model of the transition of the electrode surface to the critical state together with the experimental concentration dependencies of the critical potential and critical overvoltage demonstrated that the dissolution of zinc from Cu5Zn8 is most probably limited by the non-stationary diffusion mass-transfer in the solid phase of the intermetallic compound. The study also demonstrated that the phase transformation during the overcritical selective anodic dissolution of the gamma-phase of Cu5Zn8 in an acetate environment accelerates following the growth of the anodic potential and is controlled by the surface diffusion of adatoms towards the three-dimensional nucleus of the copper phase with instantaneous nucleation.

Supported copper has a great potential for replacing the commercial palladium-based catalysts in the field of selective alkynes/alkadienes hydrogenation due to its excellent alkene selectivity and relatively high activity. However, fatally, it has a low catalytic stability owing to the rapid oligomerization of alkenes on the copper surface. In this study, 2.5 wt% Cu catalysts with various Cu:Zn ratios and supported on hierarchically porous alumina (HA) were designed and synthesized by deposition–precipitation with urea. Macropores (with diameters of 1 μm) and mesopores (with diameters of 3.5 nm) were introduced by the hydrolysis of metal alkoxides. After in situ activation at 350 °C, the catalytic stability of Cu was highly enhanced, with a limited effect on the catalytic activity and alkene selectivity. The time needed for losing 10% butadiene conversion for Cu1Zn3/HA was ~40 h, which is 20 times higher than that found for Cu/HA (~2 h), and 160 times higher than that found for Cu/bulky alumina (0.25 h). It was found that this type of enhancement in catalytic stability was mainly due to the rapid mass transportation in hierarchically porous structure (i.e., four times higher than that in bulky commercial alumina) and the well-dispersed copper active site modified by Zn, with identification by STEM–HAADF coupled with EDX. This study offers a universal way to optimize the catalytic stability of selective hydrogenation reactions.

Cryptocaryons irritans is a ciliate parasite responsible for cryptocaryoniasis, leading to considerable economic losses in aquaculture. It is typically managed using a copper–zinc alloy (CZA), effectively diminishing C. irritans infection rates while ensuring the safety of aquatic organisms. Nevertheless, the precise mechanism underlying cuproptosis induced C. irritans mortality following exposure to CZA remains enigmatic. Therefore, this study delves into assessing the efficacy of CZA, investigate cuproptosis as a potential mechanism of CZA action against C. irritans , and determine the alterations in antioxidant enzymes, peroxidation, and lipid metabolism. The mRNA expression of dihydrolipoamide S-acetyltransferase was upregulated after 40 and 70 min, while aconitase 1 was implicated in cuproptosis following 70 min of CZA exposure. Furthermore, the relative mRNA levels of glutathione reductase experienced a significant increase after 40 and 70 min of CZA exposure. In contrast, the relative mRNA levels of glutathione S-transferase and phospholipid-hydroperoxide glutathione peroxidase were significantly decreased after 70 min, suggesting a disruption in antioxidant defense and an imbalance in copper ions. Lipidomics results also unveiled an elevation in glycerophospholipids metabolism and the involvement of the lipoic acid pathway, predominantly contributing to cuproptosis. In summary, exposure to CZA induces cuproptosis in C. irritans , impacts glutathione-related enzymes, and alters glycerophospholipids, consequently triggering lipid oxidation. [Display omitted] • CZA didn't affect the fish growth rate. • CZA can cause cuproptosis in C. irritans and disturb antioxidant enzymes. • Glycerophospholipids increases and lipoic acid pathway input in cuproptosis death in C. irritans. [ABSTRACT FROM AUTHOR]

Room-temperature ball milling technique has been successfully employed to fabricate copper-zinc graphene nanocomposite by high-energy ball milling of elemental Cu, Zn, and graphene. Copper powder reinforced with 1-wt.% nanographene sheets were mechanically milled with 5, 10, 15, and 20 wt.% Zn powder. The ball-to-powder weight ratio was selected to be 10:1 with a 400-rpm milling speed. Hexane and methanol were used as a process control agent (PCA) during composite fabrication. The effect of PCA on the composite microstructure was studied. The obtained composites were compacted by a uniaxial press under 700 MPa. The compacted samples were sintered under a controlled atmosphere at 1023 K for 90 min. The microstructure, mechanical, and tribological properties of the prepared Cu-Zn GrNSs nanocomposites were studied. All results indicated that composites using hexane as PCA had a uniform microstructure with higher densities. The densities of sintered samples were decreased gradually by increasing the Zn percent. The obtained composite contained 10 wt.% Zn had a more homogeneous microstructure, low porosity, higher Vickers hardness, and compression strength, while the composite contained 15 wt.% Zn recorded the lowest wear rate. Both the electrical and thermal conductivities were decreased gradually by increasing the Zn content.

The influence of heat treatment process on microstructure and physiochemical properties of Cu77Zn21 alloy was studied. Samples were heated from 300 to 700°C for 15 minutes and gradually cooled to room temperature. Samples were characterized using mechanical testing and surface analysis techniques. It was observed that the grain size increases with the increasing temperature. The decrease in hardness is due to composition change of the Cu-Zn alloy attributed to zinc diffusion.XRD shows the presence of only α brass with a preferential orientation along the (111) plane. The analyses show that temperature affects the crystalline parameters. The rms microstrain was reduced mainly by thermal activation. The heat treatment promotes atomic diffusion and leads to a better crystallinity of the particles. The results of Raman investigations confirmed the changes in the Cu-Zn alloy surface composition with a clear enrichment in CuO. This behavior correlates with the results obtained by mechanical testing. [ABSTRACT FROM AUTHOR]

In this work, micrometer copper-zinc alloy particles-reinforced particleboard wood flour/poly (lactic acid) (mCu-Zn/PWF/PLA) wood plastic composites with high gloss and antibacterial properties for 3D printing were prepared by a melt blending process. The structure and properties of the composites with different contents of mCu-Zn were analyzed by means of mechanical testing, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and antibacterial testing. The results showed that the mechanical properties, thermal stability, and antibacterial performance of the composites were significantly improved, as mCu-Zn was added into the wood plastic composites. When adding 2 wt.% mCu-Zn, the flexural strength of mCu-Zn/PWF/PLA composites (with 5 wt.% of particleboard wood flour) (PWF) increased by 47.1% compared with pure poly (lactic acid) (PLA), and 18.9% compared with PWF/PLA wood plastic composites. The surface gloss was increased by 1142.6% compared with PWF/PLA wood plastic composites. Furthermore, the inhibition rates of mCu-Zn/PWF/PLA composites against Escherichia coli reached 90.43%. Therefore, this novel high gloss and antibacterial wood plastic composites for fused deposition modeling (FDM) 3D printing have potential applications in personalized and classic furniture, art, toys, etc.

Thermally conductive materials usually need to be used within a certain temperature range (−20 to 100 °C). However, the thermal conductivity conventional thermally conductive materials have a negative temperature dependence in this temperature range. This leads to a reduction in the thermal conductivity of thermally conductive materials at high temperatures (around 100 °C). Therefore, the thermally conductive composite of high impact polystyrene (HIPS) / copper-zinc alloy (Cu alloy) with thermal conductivity that does not vary with temperature was successfully prepared in the range of − 20∼80 °C in this work. The negative contribution of thermal conductivity due to thermal expansion of the composite is countered by the positive temperature-dependent property of thermal conductivity unique to metal alloys. The effect of Cu alloy content on the variation pattern of thermal conductivity of the composite with temperature was investigated. The results show that the higher the Cu alloy content, the higher the thermal conductivity tends to be in positive dependence. The material can be used in chemical heat exchangers and other devices that require high temperature heat dissipation, and provides accurate data for chemical production heat calculation. [Display omitted] • Prepared composites with no temperature dependence of thermal conductivity. • Equation for predicting λ of composite at various temperatures is proposed by EMT. • Analyzed the effect of thermal expansion on the thermal conductivity of composite. [ABSTRACT FROM AUTHOR]

Abstract: The current study involves fabrication and characterization of bio-composite scaffolds containing chitosan (CS), nano-hydroxyapatite (nHAp) and Cu–Zn alloy nanoparticles (nCu–Zn) by freeze drying technique. The fabricated composite scaffolds (CS/nHAp and CS/nHAp/nCu–Zn) were characterized by SEM, EDX, XRD and FT-IR studies. The addition of nCu–Zn in the CS/nHAp scaffolds significantly increased swelling, decreased degradation, increased protein adsorption, and increased antibacterial activity. The CS/nHAp/nCu–Zn scaffolds had no toxicity towards rat osteoprogenitor cells. So the developed CS/nHAp/nCu–Zn scaffolds have advantageous and potential applications over the CS–nHAp scaffolds for bone tissue engineering. [Copyright &y& Elsevier]

Supported copper has a great potential for replacing the commercial palladium-based catalysts in the field of selective alkynes/alkadienes hydrogenation due to its excellent alkene selectivity and relatively high activity. However, fatally, it has a low catalytic stability owing to the rapid oligomerization of alkenes on the copper surface. In this study, 2.5 wt% Cu catalysts with various Cu:Zn ratios and supported on hierarchically porous alumina (HA) were designed and synthesized by deposition–precipitation with urea. Macropores (with diameters of 1 μm) and mesopores (with diameters of 3.5 nm) were introduced by the hydrolysis of metal alkoxides. After in situ activation at 350 °C, the catalytic stability of Cu was highly enhanced, with a limited effect on the catalytic activity and alkene selectivity. The time needed for losing 10% butadiene conversion for Cu1Zn3/HA was ~40 h, which is 20 times higher than that found for Cu/HA (~2 h), and 160 times higher than that found for Cu/bulky alumina (0.25 h). It was found that this type of enhancement in catalytic stability was mainly due to the rapid mass transportation in hierarchically porous structure (i.e., four times higher than that in bulky commercial alumina) and the well-dispersed copper active site modified by Zn, with identification by STEM–HAADF coupled with EDX. This study offers a universal way to optimize the catalytic stability of selective hydrogenation reactions. [ABSTRACT FROM AUTHOR]

Room-temperature ball milling technique has been successfully employed to fabricate copper-zinc graphene nanocomposite by high-energy ball milling of elemental Cu, Zn, and graphene. Copper powder reinforced with 1-wt.% nanographene sheets were mechanically milled with 5, 10, 15, and 20 wt.% Zn powder. The ball-to-powder weight ratio was selected to be 10:1 with a 400-rpm milling speed. Hexane and methanol were used as a process control agent (PCA) during composite fabrication. The effect of PCA on the composite microstructure was studied. The obtained composites were compacted by a uniaxial press under 700 MPa. The compacted samples were sintered under a controlled atmosphere at 1023 K for 90 min. The microstructure, mechanical, and tribological properties of the prepared Cu-Zn GrNSs nanocomposites were studied. All results indicated that composites using hexane as PCA had a uniform microstructure with higher densities. The densities of sintered samples were decreased gradually by increasing the Zn percent. The obtained composite contained 10 wt.% Zn had a more homogeneous microstructure, low porosity, higher Vickers hardness, and compression strength, while the composite contained 15 wt.% Zn recorded the lowest wear rate. Both the electrical and thermal conductivities were decreased gradually by increasing the Zn content. [ABSTRACT FROM AUTHOR]

Abstract: In this paper several aspects involved in the chlorination of a Zn 48% wt.–Cu alloy between 250 and 500°C are investigated. The starting temperature for the chlorination of the alloy is determined, which is different from those of pure metals. Analysis of the chlorination thermogravimetric curves and reaction products reveal that there are interactions between reactants and products during the reaction, and that volatilization of ZnCl2 is diminished during the alloy chlorination. Metallic copper is detected at intermediate stages of the chlorination, and this element, which is not present in the initial sample, appears during the chlorination reaction. An oxidation–reduction type reaction between copper chlorides and metallic zinc is proposed to explain the behaviour observed. The occurrence of this reaction at room temperature was confirmed in separate experiments. At the beginning of the reaction, formation of zinc oxichloride was detected that is being formed from the zinc oxide layer that covers the alloy surface. According to the results obtained, a reaction mechanism is presented for the alloy chlorination. [Copyright &y& Elsevier]

Abstract: The initial stages of oxidation of Cu0.7Zn0.3(111) exposed to O2 at low pressure (7.0×10−7 mbar), at room temperature and at 120°C, have been studied by auger electron spectroscopy (AES), low energy electron diffraction (LEED) and, for the first time on brass surfaces, by scanning tunneling microscopy/spectroscopy (STM/STS). AES measurements show that the oxidation at room temperature quickly reaches saturation. The comparison with data obtained on Cu(111) indicates a higher and faster uptake of oxygen on brass. The STM images show that, contrarily to what was observed on Cu(111), the oxide nucleation is homogeneous on the surface. The behaviour at 120°C is drastically different. The oxygen uptake increases considerably and saturation is obtained for higher exposure. The AES signals of zinc and oxygen increase linearly with the exposure, indicating the growth of zinc oxide at the surface promoted by the segregation of Zn from the bulk. At saturation, STM images indicate that the surface is covered by ZnO islands. STS reveals that between the ZnO islands the conductive substrate surface is measured. Moreover two types of islands are differentiated by local spectroscopy. They may be attributed to ZnO{0001} islands of different polarity. [Copyright &y& Elsevier]

The characteristics of recrystallization determine the hot working process, the final properties, and the limits of the high-temperature service of metal materials. Metal recrystallization theory is also one of the most basic scientific issues in materials science. In this paper, a novel continuous heating stress relaxation method was proposed to determine the recrystallization temperature of metal sheets, and the recrystallization behavior of H65 brass with a cold rolling reduction rate of 70% is studied by this method. The results show that the stress relaxation method can accurately obtain the recrystallization temperature characteristic points of metal samples. The effects of external load and heating rate on stress relaxation are analyzed. Compared with the hardness method, the stress relaxation method can continuously monitor the mechanical properties of materials during recrystallization. The stress relaxation method can be used to determine the recrystallization activation energy Q r of metal through the less experimental workload. The Q r of the brass samples determined by the stress relaxation method is 127 KJ/mol, which is very close to the 131 KJ/mol determined by the hardness method. • Stress relaxation method can actually determine recrystallization temperature. • Stress relaxation method is simpler to determine activation energy. • The advantages and disadvantages of the stress relaxation method are discussed. [ABSTRACT FROM AUTHOR]

In this work, micrometer copper-zinc alloy particles-reinforced particleboard wood flour/poly (lactic acid) (mCu-Zn/PWF/PLA) wood plastic composites with high gloss and antibacterial properties for 3D printing were prepared by a melt blending process. The structure and properties of the composites with different contents of mCu-Zn were analyzed by means of mechanical testing, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and antibacterial testing. The results showed that the mechanical properties, thermal stability, and antibacterial performance of the composites were significantly improved, as mCu-Zn was added into the wood plastic composites. When adding 2 wt.% mCu-Zn, the flexural strength of mCu-Zn/PWF/PLA composites (with 5 wt.% of particleboard wood flour) (PWF) increased by 47.1% compared with pure poly (lactic acid) (PLA), and 18.9% compared with PWF/PLA wood plastic composites. The surface gloss was increased by 1142.6% compared with PWF/PLA wood plastic composites. Furthermore, the inhibition rates of mCu-Zn/PWF/PLA composites against Escherichia coli reached 90.43%. Therefore, this novel high gloss and antibacterial wood plastic composites for fused deposition modeling (FDM) 3D printing have potential applications in personalized and classic furniture, art, toys, etc. [ABSTRACT FROM AUTHOR]