Casting of high surface area electrodes enabled by low-temperature welding of copper nanoporous powders and nanoparticles hybrid feedstocks
Casting of high surface area electrodes enabled by low-temperature welding of copper nanoporous powders and nanoparticles hybrid feedstocks
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DOI：
10.1016/j.apmt.2023.101802
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发表时间：
2023-06
影响因子：
8.3
通讯作者：
S. Niauzorau;N. Kublik;Emmanuel Dasinor;A. Hasib;Aliaksandr Sharstniou;B. Azeredo
中科院分区：
文献类型：
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作者：
S. Niauzorau;N. Kublik;Emmanuel Dasinor;A. Hasib;Aliaksandr Sharstniou;B. Azeredo
纳米多孔金属粉末被提议作为用于制氢的电极、电池中的集流体或推进剂中的活性材料，以克服它们的大块固体对应物的反应动力学的限制。然而，它们通过粉末冶金固结成3D部件，同时保持高机械性能，受到烧结过程中热力学不稳定性和流动性差的限制。本文展示了通过Cu-Al气体雾化前体的高通量（即，0.1 kg/hr），中等流动性（即，Carney流速为32.9s/50 g），中等氧含量（即，< 12原子%），高表面积（1012 m2/g）和无沉淀。由PCu（65.5 - 91.2体积%）组成的混合原料的纳米级可焊性和铜纳米颗粒（8.8 - 34.5体积%）在低至其熔点三分之一的温度下烧结，克服了PCU的亚稳定性，以保持其高表面积。在300 - 700 °C的温度下在还原性气氛中采用开式压铸，得到具有3.6 - 17.8MPa的极限压缩强度的部件，同时形成具有保留的纳米孔隙率的导电固体（即，孔径24 - 36纳米）。这样的原料可以与基于粉末的制造工艺（例如粉末注射成型和增材制造）集成以产生复杂的架构。
Nanoporous metallic powders are proposed as electrodes for hydrogen production, current collectors in batteries, or active material in propellants to overcome limitations in reaction kinetics of their bulk solid counterpart. However, their consolidation into 3D parts via powder metallurgy while maintaining high mechanical performance is limited by their thermodynamic instability during sintering and poor flowability. This paper demonstrates the synthesis of spherical nanoporous copper powders (PCu) via dealloying of Cu-Al gas-atomized precursors with high-throughput (i.e., 0.1 kg/hr), moderate flowability (i.e., Carney flowrate of 32.9 s/50 g), moderate-oxygen content (i.e., < 12 at.%), high-surface area (∼12 m2/g) and free of precipitates. The nanoscale weldability of hybrid feedstocks composed of PCu (65.5 – 91.2 vol.%) and copper nanoparticles (8.8 – 34.5 vol.%) were harvested to sinter them at temperatures as low as a third of its melting point and overcome the metastability of PCu to preserve its high-surface area. Open-die casting in reducing atmospheres was employed at temperatures between 300 – 700 °C resulting in parts with ultimate compression strength of 3.6 – 17.8 MPa while forming electrically conductive solids with preserved nanoporosity (i.e., pore size 24 – 36 nm). Such feedstocks may be integrated with powder-based manufacturing processes such as powder injection molding and additive manufacturing to produce complex architectures.