A multi-core through steel wire reinforced brass composite rod was fabricated using a solid-liquid continuous casting and composite technique. Microstructure evolution, interface, mechanical properties, and deformation behavior of the composite rod during the room temperature tensile process were studied. The results showed that the steel wires in the composite rod were distributed in a regular hexagonal shape, forming a brass/steel interface with good metallurgical bonding. After annealing at 700 degrees C for 1h, the tensile strength of the composite rod was 376 MPa, and the elongation to failure was 46.3 %, whose tensile strength was 21 % higher than that of the brass cladding single steel wire composite rod with the same steel percentage. During uniform tensile deformation, each steel wire in the composite rod experienced a consistent and uniform tensile stress. When the tensile deformation became unstable, the central steel wire experienced the highest level of tensile stress, initially leading to the occurrence of necking and fracture. As the tensile strain increased, the brass grains underwent twisting and rotation. In addition, the steel grains were elongated along the tension direction, and the number of low-angle boundaries increased. The straight brass/steel interface was transformed into a wavy pattern with a good bonding interface, indicating that the composite rod exhibited excellent synergetic deformation capability. The mixing laws based on hybrid effects have good applicability to multi-core through steel wire reinforced brass composite rod, with a strength error of less than 7 %.

Al-30Zn-3Cu-2.5Si high Zn Al-based alloy was taken as the research object, the effects of Er and Zr on the microstructure and mechanical properties of as-cast and heat-treated alloys were investigated, and the action mechanism was analyzed and discussed. The results show that the grain size of the alloy can be obviously refined by adding 0.10wt% Er and 0.10wt% Zr, the average grain size is reduced from 74.28 mu m to 60.01 mu m, and the grains of alpha-Al are changed into fine equiaxed grains. The addition of rare earth elements Er and Zr can form fine particles of Al-3(Er, Zr) in the alloy and pin dislocations to improve the mechanical properties of the alloy. After adding Er and Zr, the tensile strength of as-cast alloy increases from 323.01 MPa to 358.29 MPa, which increases by 10.93%; the yield strength increases from 309.33 MPa to 315.00 MPa, which increases by 1.83%; the elongation barely changes. The tensile strength and yield strength of the alloy strengthened by solution-aging heat treatment are 449.48 and 408.51 MPa, which are 25.45% and 29.68% higher than those of the as-cast alloy, respectively. The coarse second phase exists at the grain boundary, which results in the poor elongation of the alloy.

A novel mechanical stirring-assisted double-melt in-situ reaction casting process was developed to prepare Cu-1TiB2 (wt

A Cu-9Ni-6Sn alloy bar with pronounced axial columnar grains and a diameter of 10.5 mm was fabricated by using directional solidification technology, which was directly cold-drawn into a superfine alloy wire with a diameter of 40 mu m without intermediate annealing. The strength and microstructure evolutions of the Cu-9Ni-6Sn alloy during the cold drawing were studied. The results indicate that twinning is more likely to occur in fiber structures ranging from 60 to 120 nm. A dual-fiber structure consisting of <111> and <100> orientations formed after cold-drawing. Unexpectedly, a large number of deformation twins were discovered within the <111> fibrous texture and later transformed into detwinning structures, disrupting the axial fibrous texture. The generation of deformation twinning primarily results from Ni and Sn elements disrupting crystal symmetry and reducing stacking fault energy of the alloy and the formation of <111> texture. The combined effects of detwinning structures and dislocation wall induced work-softening of the alloy, enabling high-strain processing and ultimately yielding nanocrystalline grains, i.e., the Cu-9Ni-6Sn alloy underwent cold drawing with a high train of 11.23 and obtained an average grain size of similar to 38 nm, which exhibited a tensile strength of 1453 MPa.

Aging is an important step in improving the comprehensive properties of Cu-3.5Ti alloy. However, both prolonged holding times and high heat treatment temperatures lead to significant oxidation and substantial energy consumption. The effects of heat treatment (HT) and electropulsing treatment (EPT) on the microstructure and mechanical properties of the solid solution Cu-3.5Ti alloy were comparatively examined in this study. The findings demonstrated that EPT quickly completed the processes of spinodal decomposition and short-range ordered to long-range ordered phase transformation, thereby fully precipitating fine and diffusive beta '-Cu4Ti phase, which greatly enhanced the precipitation strengthening effects. In addition to enhancing the strength of the alloy, EPT significantly reduced the peak aging time (to just 1/12 of that of HT) and greatly increased the plasticity (elongation to failure rose by 47 % compared to HT). The main reason for the rapid completion of the spinodal decomposition and the full precipitation process by the EPT was the additional free energy provided by the electropulsing, which significantly accelerated the Ti atomic diffusion and lowered the nucleation barrier of the beta '-Cu4Ti phase. EPT is a toughening heat treatment process for metallic materials, which offers the advantages of high efficiency, low energy consumption, and low cost.

Recrystallization annealing is a necessary process for refining the grain of processed metallic materials and eliminating work hardening. However, it can cause a large amount of precipitation and coarsening of the second phase in supersaturated solid solution alloys, which is detrimental to the subsequent processing and aging processes aimed at controlling the precipitation phase. This article compared the effects of electropulsing (EPT) and conventional heat treatment (CHT) processes on the microstructure and mechanical properties of cold-rolled Cu-3.5Ti alloy. The results indicated that compared with CHT, EPT achieved full recrystallization of the alloy at a lower temperature (650 °C, 100 °C lower than CHT) and in a shorter time (10s, 1/360 of CHT), and effectively inhibited the precipitation of β-Cu4Ti phase, resulting in a fine and uniform supersaturated solid solution. This process significantly improved both the strength and plasticity of the alloy. The yield strength, tensile strength and elongation to failure of the EPT-650 °C/10s sample were 570MPa, 598MPa and 21.2%, respectively, which were 27.8%, 25.9% and 19.1% higher than those of the CHT-750 °C/1h sample. EPT significantly increased the recrystallization nucleation rate of the alloy, while its rapid heating method inhibited the precipitation of β-Cu4Ti phase, ensuring the recrystallization process was not affected by the precipitated phase, which was the main reason for rapid recrystallization and grain refinement of Cu-3.5Ti alloy by EPT at lower temperatures and shorter time.

Copper-based alloys have garnered significant attention for their potential in antimicrobial applications aimed at mitigating medical-related infections. Nonetheless, the alloying elements in conventional copper alloys frequently exhibit biotoxicity. This study explored the corrosion behavior, antimicrobial activity, and ion release of Cu-Fe alloys with varying iron contents and aging treatment. The results indicate that increasing the iron content in Cu-Fe alloys and applying appropriate aging treatment can enhance both the antibacterial efficiency and corrosion rate. Transmission electron microscopy (TEM) observations revealed a corrosion mechanism in which dispersed iron phases act as nucleation sites. These nanoscale precipitates increase the Cu/Fe interfacial area, thereby promoting ion release at the interface. Furthermore, in-situ scanning electron microscopy (SEM) revealed that corrosion products are more likely to detach in iron-rich segregated areas, which effectively promotes the sustained release of copper ions.

Improving high-temperature strength and resistance to high-temperature softening is an important method to promote the application of high-performance Cu-Cr-Zr alloy in fields such as resistance welding electrodes and high-speed railway contact wires. A Cu-1.0Cr-0.4Zn-0.1Zr-0.05Si alloy was designed and the combining effects of Zn and Si elements on the microstructure and high-temperature mechanical properties of the alloy were studied. The tensile strength of the alloy at room temperature was 556 MPa, and it was 349 MPa at 500 & DEG;C with a softening temperature of 620 & DEG;C. The main strengthening phases of the alloy were submicron Cr3Si and nano-scaled Cr-rich precipitates. The Zn elements were uniformly solid-solved in the Cu matrix, and the addition of Zn and Si elements significantly retarded the phase transformation of the Cr-rich precipitates. Thermodynamics and kinetics analysis showed that Zn and Si elements promoted the dispersive precipitation of the nano-scaled FCC coherent Cr-rich precipitates by reducing the nucleation energy barrier, while the Si and Zr elements inhibited the coarsening of the Cr-rich precipitates by enriching at the phase boundaries, effectively impeding dislocation motion and grain boundary migration, which mainly contributed to good high-temperature strength and resistance to softening of the Cu-Cr-Zn-Zr-Si alloy.

铜铁合金以其高强度、优良的导电导热性能和独特的软磁性能为特点,在低频段表现出卓越的电磁屏蔽性能.作为磁性导电材料和电磁屏蔽材料等,铜铁合金在航空航天电子对抗屏蔽系统、机器人通信控制设备以及OLED屏等领域具有广阔的应用前景.此外,还可作为抗菌抑菌材料,应用于医用敷料和医疗器械等行业.然而,Cu-Fe合金制备过程中的亚稳液相分离现象限制了合金的工业化生产.本文回顾了铜铁合金的性能与应用和制备方法,探讨了Cu-Fe合金制备过程中遇到的挑战,并提供了潜在的解决方案,让工业界和学术界了解Cu-Fe合金的优势,促进Cu-Fe合金制造业的发展.

A Cu–1.3Ni–1.2Co–0.7Si–0.3Cr–0.1Mg alloy with high strength and medium conductivity was designed and prepared. The effects of multistage thermomechanical treatment on the microstructure and properties of the alloy and its strengthening mechanism were studied. The results showed that a large number of nanoscale β-Ni3Si, δ-(Ni,Co)2Si and Cr phase particles precipitated in the high-density dislocation region and sub-grain boundaries during aging, and submicron Cr3Si phase particles formed during solidification of the alloy. The tensile strength, yield strength and electrical conductivity of the alloy were 882 MPa, 857 MPa and 46.7% (IACS), respectively. The main strengthening mechanisms of the alloy were precipitation strengthening, strain strengthening and sub-structure strengthening through the strengthening model calculation and measured strength.

The evolution of grain structure, precipitates and mechanical properties of the ZL205A alloy prepared by wire arc additive manufacturing were investigated. The results show that the as-deposited alloy consists of equiaxed and columnar grains in the bottom region. As the deposition height increases, the alloy mainly consists of equiaxed grains. The evolution of columnar to equiaxed grains is explained by the solidification theory. The needle-like q0-Al2Cu precipitates in Cu-rich regions surrounding the a-Al thorn q-Al2Cu eutectics. As the part deposited first is subjected to multiple cycles of heating by the subsequently deposited layers, the volume fraction and average size of q0 precipitates gradually decrease with the increase of deposition heights. The microhardness of the as-deposited alloy fluctuates in the range of 74.6-84.5 HV. The mechanical properties of the horizontal specimens at different heights are affected by the combination of grain structure, precipitates and pores, and that of the specimens in the middle region are optimal. The mechanical properties of the horizontal and vertical specimens show isotropic. Attributed to the grain boundary strengthening and precipitation strengthening, the yield strength (132.9 MPa) and elongation (15.9%) of the as-deposited alloy are approximately 31.3% and 211.8% higher than that of the as-cast alloy, respectively. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

As a variant of zinc blend structure, p -type semiconducting Cu 2 SnSe 3 exhibits high potential in the field of thermoelectric energy conversion, due to the low lattice thermal conductivity and large abundance of consisting elements. Till now, the bottleneck of achieving comparable thermoelectric performance in Cu 2 SnSe 3 with state-of-art thermoelectric material systems is its unsatisfactory electrical power factor. In this work, we realized a simultaneous increment of charge carrier concentration and mobility through In/Sb co-doping at Sn site; detailed X-ray diffraction (XRD) Reltveld refinement and density function theory (DFT) band structure calculation revealed a gradual phase structure (and associated band structure) transition from low-symmetry monoclinic to high-symmetry cubic one, which was further verified by Cs-corrected scanning transmission electron microscopy (Cs-corrected STEM) characterization. Eventually, we achieved a peak figure of merit ZT max ~ 0.90 at 773 K and average ZT avg ~ 0.36 (323-773 K) in the composition of Cu 2 (Sn 0.85 In 0.05 Sb 0.05 Ti 0.05 )Se 3 , representing the state of art for all Cu 2 SnSe 3 -based thermoelectric materials reported thus far.

In order to shorten the production process of Cu-Fe alloy and improve the microstructure homogeneity and properties and properties, Cu-10 wt%Fe alloy billet was prepared by double-melt mixed casting process and then cold rolled. Microstructure and mechanical property evolutions of the alloy and its deformation behaviours were investigated. The results showed that the alloy billet had dispersed spherical Fe phase particles and dendritic Fe phases. The alloy billet had excellent plasticity, and the cumulative cold rolling reduction without intermediate annealing reached 98%. When the reduction was 30%, numerous dislocations produced in the Cu matrix and the Cu matrix near the Fe phase underwent local crystal rotation, and the Fe phase particles deformed slightly. When the reduction exceeded 90%, dynamical recrystallization of the Cu matrix happened, fine grains with average diameter of similar to 300 nm formed, and the dendritic Fe phases were evenly distributed along the rolling direction, which mainly contributed to achieve large-reduction of cold rolling. When the reduction was 98%, the tensile strength and hardness increased from 340 MPa and 87 HV of the as-cast alloy to 543 MPa and 164 HV, respectively, and the elongation and electrical conductivity was reduced to 3.0% and 13.5%IACS. A process of double-melt mixed casting -> cold rolling can work as a novel high-efficiency and compact method to produce Cu-Fe alloy sheet.

Cu–Fe alloys with different Fe contents were prepared by vacuum hot pressing. After hot rolling and aging treatment, the effects of Fe content on microstructure, mechanical properties and electrical conductivity of Cu–Fe alloys were studied. The results show that, when w(Fe)<60%, the dynamic recrystallization extent of both Cu phase and Fe phase increases. When w(Fe)≥60%, Cu phase is uniformly distributed into the Fe phase and the deformation of alloy is more uniform. With the increase of the Fe content, the tensile strength of Cu–5wt.%Fe alloy increases from 305 MPa to 736 MPa of Cu–70wt.%Fe alloy, the elongation decreases from 23% to 17% and the electrical conductivity decreases from 31%IACS to 19%IACS. These results provide a guidance for the composition and processing design of Cu–Fe alloys.