The W-Cu functionally graded material (FGM) interlayer is considered an effective approach to mitigate thermal mismatch between W and CuCrZr, but achieving robust interfacial bonding between W and W-Cu FGM remains a key technical challenge. In this work, an interface-strengthening strategy combining W surface sandblasting with spark plasma sintering (SPS) was developed to reinforce the interfacial bonding of joints. The impact of W surface sandblasting on the interfacial morphology, element diffusion, and comprehensive performance of the joints was thoroughly evaluated. Results reveal that the formation of a serrated interface structure significantly enhances interfacial bonding strength and alters the crack propagation path. Furthermore, surface defects introduced by W surface sandblasting, such as grain boundaries and dislocations, serve as fast diffusion channels, thereby promoting elemental diffusion and strengthening the interfacial bonding. Notably, the joint fabricated with a sandblasting pressure of 0.7 MPa achieves a shear strength of 223.35 MPa, corresponding to a 55.77 % increase over the untreated joint. Additionally, the sandblasted joint also exhibited improved thermal conductivity and interfacial bonding rate at elevated temperatures, indicating superior thermal stability. This work provides a practical and scalable strategy to achieve reliable W/CuCrZr joints in plasma-facing components (PFCs).

A novel method was developed to fabricate WCu functionally graded materials (WCu FGMs) featuring a pure tungsten layer. WO3 served as a pore-forming agent, was mixed with W powders in varying proportions. The mixture undergoes stacking pressing, hydrogen reduction and sintering to form a W skeleton with gradient porosity. Cu was subsequently infiltrated to produce the WCu FGMs. The effects of sintering temperature on microstructure, W skeleton porosity, Cu content and thermal conductivity of the WCu FGMs were systematically investigated. Experimental results demonstrate that W skeleton porosity decreased with increasing sintering temperature. At 2000 °C, W skeleton porosity ranged from 4.3% to 56.85%, with Cu content in the infiltrated WCu FGMs varying from 0% to 37.9 wt% and thermal conductivity reaching 223 W·(m·K)−1.

The large mismatch in the physical properties of W and Cu limits the rapid fabrication of W-Cu composites with both high densification and a homogeneous microstructure by conventional methods. In this study, W skeletons with controllable pore structures were produced from W powder using ultrafast high-temperature sintering (UHS), followed by Cu infiltration to obtain W-Cu composites. UHS completes skeleton sintering within an extremely short time, and the sintering temperature effectively regulates pore connectivity and the open and closed pore fraction. Increasing the sintering temperature reduces total porosity of the W skeleton from 41.4% to 32.9% while increasing closed porosity from 1.3% to 5.2%. Consequently, the open porosity loss decreases Cu content from 22.2 wt.% to 13.8 wt.% and lowers relative density from 97.1% to 92.9%. Higher skeleton sintering temperatures enhance mechanical performance, with microhardness increasing from 233.2 HV to 281.4 HV and tensile strength from 323.4 MPa to 384.2 MPa. In contrast, thermal conductivity decreases from 203.2 W·m-1·K-1 to 173.2 W·m-1·K-1 due to increased closed porosity and reduced continuity of the Cu network. Overall, tailoring the interconnected pore structure of W skeletons via UHS temperature control enables wide tunability of mechanical and thermal properties in W-Cu composites.

In this study, a novel method for preparing continuous W-Cu functionally graded materials (FGMs) was developed. The W powder was distributed in layers within a liquid medium based on differences in particle size. W skeletons with a porosity gradient were formed through degreasing, reduction, and sintering processes. Finally, W-Cu FGMs with continuous variation in W(Cu) composition were prepared by Cu infiltration. To further broaden the range of W and Cu composition distribution in the W-Cu FGMs, WO3 was introduced as a poreforming agent. The effects of WO3 addition on the microstructure and properties of the W-Cu FGMs were investigated, along with an analysis of the sedimentation process. The results demonstrate the feasibility of fabricating W-Cu FGMs with a pure tungsten layer using this preparation method, which yields a continuous gradient in composition. Additionally, when 10 wt% WO3 was added, the gradient range of W-Cu FGMs is maximized, with Cu content gradually increasing from 0 to 45.7 wt%, the relative density of each region exceeds 95 %. The thermal conductivity reaches up to 256 W & sdot;(m & sdot;K)- 1.

Low-energy and high-flux helium plasma irradiation can cause serious erosion and damage to the surface of tungsten (W), resulting in the formation of defects, holes and fuzz structures. The formation of these surface structures will significantly degrade the material's thermal conductivity, disrupt surface temperature distribution, and lead to surface degradation, thereby reducing the irradiation resistance of the material.To address this issue, this study introduces lanthanum oxide (La2O3) as a second phase to effectively reduce large-angle grain boundaries on the W surface and inhibit helium bubble formation by preventing helium plasma accumulation. The result shows that compared with pure tungsten (PW), W-La2O3 composite (the mass fraction of La2O3 second phase is 1 %) exhibits stronger resistance to helium plasma irradiation. Under the irradiation condition of helium plasma beam current of 2.91x1021 ions/m2 center dot s and the dose of 3.492x1024 ions/m2, the W-La2O3 composite surface presents a wavy surface structure, which is different from the typical fuzzy surface structure formed on the pure W, indicating a significant alteration in defect evolution. With the irradiation dose increased to 13.020x1024 ions/m2, the wavy surface structure disappears, and the surface structure exhibits a classical pyramidal surface structure. The simulation results of SRIM software further reveal that the La2O3 second phase helps to transfer the helium plasma gathered on the W surface to a deeper place inside the material. In this way, the aggregation of helium ions on the surface is effectively alleviated, the formation process of the fuzz structure is delayed, and the stability of the irradiated surface structure is significantly improved. This study provides a novel design strategy for improving the anti-radiation performance of W-based plasma-facing materials in extreme fusion environments.

Owing to their high electrical/thermal conductivity, Gr-Cu composites have been increasingly investigated as advanced electrical and thermal management materials. The formation of Cu-Gr interface/microstructure are widely reported, however, the impact of Gr on the Cu matrix has not been clearly investigated where the Cu orientation may be affected by Gr in deposition and deformation process. In this work, we first report the Gr as template to transfer commercial polycrystalline Cu foil to fully Cu{111} textured via a scalable hot-pressing process. The as-synthesized Gr-Cu laminated structure with poly-crystal Cu could be inversed to totally (111) orientation as Gr-Cu{111}by hot-pressing and inversion process could only be triggered by “pressure”. The as-synthesized Cu texture, with very few misoriented grains could be formed in the resulting Gr-Cu composite materials. The continuous Gr layer promotes the phenomenon of preferential growth of Cu(111) grain under downward pressure, and Cu(111)/Gr shows the lowest binding energy, -0.501 J/m2, which imply that Cu grains in Cu/Gr composite are more likely to shift towards Cu(111) under pressure. The anisotropic thermal conductivity could be enhanced to 477 W/mK by the highly oriented Cu{111} texture due to little in-plane grain-boundaries. It is very likely that this approach can be scaled up to achieve exceptionally large size and high-quality Cu{111} textured composite in order to realize a number of industrial-level applications such as high-power electronic devices at low cost.

Additive manufacturing (AM) of cemented carbide is attracting a progressively greater focus within the scope of production research. Among various AM techniques, direct ink writing (DIW) stands out for its operational simplicity, elimination of laser systems, and room-temperature processing capability. However, the challenges in regulating the rheological properties of high-solid-content aqueous WC-Co slurries and achieving sintering densification remain key bottlenecks hindering its widespread application. This study has formulated an aqueous WC-8Co slurry containing 92 wt% solids with rheology performance favorable for DIW, using deionized water as the solvent while controlling additive type and proportion. Subsequent debinding and sintering of printed green bodies achieved a relative density of 98.55% and a hardness of 1825 ± 29 HV30. These promising properties could be attributed to their refined microstructure featuring uniform submicron grains (0.57 ± 0.01 μm) and negligible porosity, which fully validates the feasibility of preparing high-performance WC-8Co cemented carbides via aqueous-based DIW technology.

The development of cost-effective and durable nonprecious metal catalysts with high oxygen reduction reaction (ORR) activity is essential for advancing anion exchange membrane fuel cells (AEMFCs). However, simultaneously achieving high ORR activity and long-term stability remains a challenge. In this work, a sulfur-doped bimetallic carbon-based catalyst (CuFe-S-N-C) is synthesized through a hydrothermal method followed by high-temperature pyrolysis. As an ORR catalyst, CuFe-S-N-C exhibits a half-wave potential (E 1/2) of 0.883 V and a Tafel slope of 65.6 mV dec-1. After 10,000 cycles, the E 1/2 decreases by only 7 mV, indicating high electrochemical durability, which could be attributed to the synergistic effects of sulfur doping and Cu/Fe dual-metal sites. When CuFe-S-N-C is used as the cathode catalyst, the AEMFC achieves a peak power of 673.8 mW cm-2 and maintains 96.2% of its initial performance after 15 h of continuous operation.

This study addresses the issue of performance limitations caused by the uneven distribution of high-melting-point elements (Mo) in ferrous powder metallurgy materials. It systematically investigates the effects of different types of Mo-containing powders (pure Mo powder, prealloyed Mo-Fe powder, and mechanically alloyed Mo-Fe powder) and sintering temperatures (1100, 1150, 1200, and 1250 degrees C) on the microstructure and properties of Fe-1.1C-15Cu-1.7Ni-7.3Cr-7Co-9Mo materials. The research aims to fundamentally improve the uniformity of Mo distribution by preparing Mo-Fe composite powders via a mechanical alloying process. As the sintering temperature increases, the material's properties exhibit a trend of first increasing and then decreasing. Within the temperature range of 1100-1150 degrees C, the rise in temperature promoted atomic diffusion and the formation of liquid Cu, which in turn facilitated particle rearrangement and pore closure, thereby improving the material's densification and mechanical properties. However, beyond 1150 degrees C, oversintering resulted in the accumulation of liquid Cu at grain boundaries and pores, inhibiting effective solid-state diffusion and densification, which led to a decline in the material's properties. At 1150 degrees C, the sintered samples containing mechanically alloyed Mo-Fe powders showed the highest performance, with a density of 7.50 g cm-3, Rockwell hardness of 92.36 HRB, and radial crushing strength of 665.72 MPa, which was superior to that of the sintered samples with pure Mo powders and prealloyed Mo-Fe powders. Additionally, the sintered samples with mechanically alloyed Mo-Fe powder demonstrated a more homogeneous microstructure and superior wear resistance, with a coefficient of friction of 0.53, a wear rate of 1.95 & times; 10-9 mm3 N-1 mm-1, and a wear mass loss of 0.0022 g, representing a 65% reduction in wear mass loss compared to sintered samples containing pure Mo powder.

In this study, W-Cu functionally graded material/CuCrZr alloy (W-Cu FGM/CuCrZr) joints was successfully bonded by hot isostatic pressing (HIP). The effects of bonding temperature (850-1000 degrees C) on the microstructure, mechanical properties and thermal conductivity of the joints were systematically investigated. In addition, their damage behavior under thermal shock cycling between 800 degrees C and room temperature was evaluated. The results indicate that increasing the bonding temperature significantly promotes the bonding strength and thermal conductivity of the joint. The joint fabricated at 1000 degrees C exhibited the optimal performance with a shear strength of 204.4 MPa and a thermal conductivity of 264.6 W/(m & sdot;K). Thermal shock testing reveals that cracks initiate at the W/CuCrZr interface due to the coefficient of thermal expansion mismatch between the W-Cu FGM and CuCrZr, as well as the extrusion of Cu under cyclic thermal stress. With increasing numbers of thermal shock cycles, these cracks then propagate along W/Cu interfaces and the fatigue CuCrZr matrix, hereby accelerating interfacial damage and leading to a marked decrease in shear strength.

The depletion of fossil fuels and growing environmental concerns are accelerating the development of clean hydrogen production technologies. Anion exchange membrane water electrolysis (AEMWE) has emerged as a promising approach owing to its cost-effectiveness and improved stability of nonprecious materials. However, its efficiency is restricted by the sluggish kinetics of the oxygen evolution reaction (OER). Herein, we report a catalyst derived from a high-entropy alloy (HEA), CuFeMnCoNi-NC/MXene, which exhibits remarkable OER activity and durability. The catalyst achieves an overpotential of 267 mV at 10 mA cm-2 and a Tafel slope of 50.9 mV dec-1. It also exhibits low charge-transfer resistance (R ct = 3.4 Omega) and a large double-layer capacitance (C dl = 27.2 mF cm-2), thereby enhancing the overall electrochemical performance. Notably, the catalyst demonstrates excellent durability, with the overpotential increasing by only 3 mV after 10,000 cyclic voltammetry (CV) cycles. An AEMWE electrolyzer assembled with this catalyst presents 1.91 A cm-2 at 2.0 V and operates at 1.0 A cm-2 for 20 h with a low degradation rate of 0.9 mV h-1.

Y-doped BaZrO3 (BZY) is a promising electrolyte for protonic ceramic fuel cells, but its poor sinter-ability usually requires high-temperature treatment and may cause phase instability. In this work, BZY electrolytes containing 1 wt

Copper conductive slurries were prepared using Cu powder as conductive phase, specially prepared SiO2-Na2O-CaO-MgO-K2O glass powder as adhesive phase, and terpineol as vehicle, in addition to some other organic gradients. The resultant Cu conductive slurry was screen-printed onto both sides of a Pb(ZrTi)O3 substrate, followed by degreasing and sintering, to obtain a single-layer capacitor consisting of a Pb(ZrTi)O3 substrate and double-sided Cu conductive films. The influence of the glass powder content in the slurry and the sintering temperature on the porosity, sheet resistivity, and adhesion strength of the resultant films was investigated. The capacitance and dielectric properties of the single-layer capacitors prepared in this work were compared with those of two commercial single-layer capacitors. The results show that Cu conductive films prepared using 10.0 wt.

Copper-clad aluminum nitride (Cu-clad AlN) substrates are critical materials for heat dissipation and interconnections in high-power electronic devices, and their performance depends heavily on the quality of the AlN/Cu interface. This paper reviews the principles, processes, and interfacial bonding mechanisms of four Cu cladding technologies: direct bonded copper (DBC), active metal brazing (AMB), direct plated copper (DPC), and thick printed copper (TPC). Additionally, it analyzes the causes of interfacial defects and the evolution of residual stresses in Cu-clad AlN substrates. Based on this, it summarizes recent improvements of Cu-clad AlN substrates in process control, surface treatment, stress management, and machine learning-assisted design. Finally, it identifies current technical challenges and outlines future development directions for Cu-clad AlN substrates. This paper provides a theoretical reference and technical basis for the fabrication and reliability enhancement of Cu-clad AlN substrates for high-power devices.

Cu-W composites are widely used in electrical, electronic and aerospace fields due to the excellent mechanical properties. In this study, basic copper carbonate, ammonium metatungstate and ammonia solution were used as raw materials to prepare Cu-20 wt% W composite powders by chemical co-precipitation combined with multistage hydrogen reduction. The effects of the hydrogen reduction process on the morphology of the powders, as well as the influence of sintering parameters on the properties of the Cu-20 W composites, were investigated. The obtained powders show a narrow size distribution (average similar to 0.41 & micro;m) and homogeneous elemental distribution, with edge dislocations on Cu (111) planes that improve sinterability. To explore the effect of sintering temperature on the composite properties and the underlying mechanism, Cu-20 W composites were sintered in the range of 930 degrees C-1020 degrees C. When sintered at 960 degrees C for 90 min, the average grain size and relative density of the composites are approximately 0.63 & micro;m and 93.79%, respectively, and the microhardness and tensile strength reach their maximum values of 143.89 Hv and 379.56 MPa. Therefore, this study further investigated the effect of holding times (60 min-150 min) on the properties of the composites at a sintering temperature of 960 degrees C. The results indicate that with holding time of 120 min, the grain size of the composite material grows to 0.75 & micro;m, at the same time the relative density and tensile strength are further improved, which are 95.84% and 422.71 MPa, respectively. This work presents a novel approach for the preparation of high-performance Cu-20 W composites.

In this study, gas-atomized CuSn10 powders were used as raw materials to manufacture 3D-printing CuSn10 samples via powder extrusion printing (PEP) technology. A laser powder bed fusion (LPBF) CuSn10 sample was prepared for comparison. The friction and wear behaviour and corrosion resistance of CuSn10 alloy were investigated. The results showed that the PEP samples prepared from unscreened CuSn10 powders had high porosity, wear rate, friction coefficient and corrosion rate. However, the properties could be improved by adjusting the powder particle sizes, including friction and wear behaviour, wear surface roughness, corrosion resistance and so on. In particular, the PEP CuSn10 samples prepared from less than 1000 mesh powders exhibited the lowest wear rate, friction coefficient and corrosion rate, which were 3.06 × 10−6 mm3 N−1 m−1, 0.565 and 0.0411 mm per year. In addition, the PEP samples prepared by the combination of coarse and fine powders exhibited a relatively smooth wear surface. On the contrary, the wear surface of the LPBF sample had some large furrows and high surface roughness after performing the friction and wear test.

Although WCu functionally graded material (FGM) interlayers have shown potential in mitigating the thermal-expansion mismatch between W and CuCrZr, insufficient bonding strength at the W/W-Cu FGM interface limits their applications in plasma-facing components (PFCs). Here, femtosecond laser texturing was introduced into the fabrication of W/W-Cu FGM/CuCrZr joints to improve interfacial bonding. The relationships among interfacial morphology, thermo-mechanical performance, and residual stress distribution were systematically established. At an optimized laser power of 6 W, regular pit arrays were generated on the W surface and subsequently evolved into a periodic interlocking W/W-Cu FGM interface during SPS. Consequently, the laser-treated joint at 6 W achieved a shear strength of 242.48 MPa, which is 1.68 times that of the untreated joint. Finite element analysis (FEA) further reveals that the interlocking architecture at the W/W-Cu FGM interface redistributes the residual-stress field and mitigates stress concentrations. Compared with the untreated joint, the laser-treated joint exhibits improved interfacial structural stability after thermal conductivity testing up to 600 °C. These findings provide a practical route to fabricate reliable W/W-Cu FGM/CuCrZr joints for engineering applications.

To develop high-performance WC-based cemented carbides, La₂O₃/WC composite powders were first synthesized via a co-precipitation-carbonization route, followed by high-energy ball milling with Co powders and subsequent spark plasma sintering (SPS) to fabricate La₂O₃/WC-10Co cemented carbides. The effects of the carbonization parameters and C/W molar ratio on the phase constitution, microstructure, and elemental distribution of the La₂O₃/WC composite powders were systematically investigated. The influence of La₂O₃ addition on the microstructural evolution and mechanical properties of the sintered cemented carbides was also further elucidated. The results show that ultrafine La₂O₃/WC composite powders with high phase purity and homogeneous elemental distribution can be obtained under the optimized carbonization conditions, with particle sizes ranging from 320 to 400 nm. The addition of La₂O₃ effectively suppresses WC grain growth during sintering and improves the mechanical properties of the cemented carbides. At a La₂O₃ addition of 0.6 wt.%, the La₂O₃/WC-10Co cemented carbide exhibits better mechanical properties with a Vickers hardness of 1951.31 HV30 and a fracture toughness of 15.36 MPa·m¹/², corresponding to increases of approximately 10% and 8.7% compared with the La₂O₃-free sample, respectively. These findings indicate that combining co-precipitation–carbonization with SPS is an effective approach for producing high-performance ultrafine-grained La₂O₃/WC-10Co cemented carbides.

Proton concentration scales positively with Ca 2+ ratio, peaking at 0.112 mol% for BFC20 at 600 °C, which achieves the best performance with 0.4 Ω cm 2 resistance and demonstrating that proton plays a critical role in electrode reaction.