Abstract

High-performance polymers such as poly(ether ether ketone) (PEEK) are appealing as composite components for a wide variety of industrial and medical applications due to their excellent thermomechanical properties. However, conventional PEEK metallization methods can often lead to poor quality control, low deposition rate, and high cost. Cold spray is a promising potential alternative to produce polymer–metal composites rapidly and inexpensively due to its relatively mild operating conditions and high throughput. In this study, we investigated the deposition characteristics of metal–polymer composite feedstock, composed of PEEK powder and copper flake in varying ratios, onto a PEEK substrate. Copper-PEEK powder blends were prepared by both hand-mixing and cryogenic milling (cryomilling), which predominantly creates composite particles with micron-scale copper domains coating PEEK particle surfaces. This process non-monotonically affects the relative dominance and length scales of the multiple contributing deposition mechanisms present in mixed-material cold spray. In low-pressure cold spray, deposits showed significant changes in deposition efficiency and composition as a result of milling, with improvements in these characteristics most dramatic at lower Cu fractions. Deposits of a cryomilled blend of nominally 30 vol.% copper in PEEK exhibited minimal porosity under scanning electron microscopy, complete retention of powder composition, and the highest deposition efficiency among all samples tested. Notably, neither neat PEEK nor neat Cu meaningfully deposited at the same mild conditions as this 30 vol.% Cu blend, indicating a synergistic departure from linear mixing rules driven by the relative balance of local deposition interactions (e.g., hard–soft, soft–soft, etc.). Intentional powder and process design toward optimizing this balance may facilitate cold spray metallization applications.

中文翻译：

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用于金属-聚合物复合材料冷喷涂增材制造的混合材料原料

摘要

聚醚醚酮 (PEEK) 等高性能聚合物由于其优异的热机械性能，作为复合材料组件在各种工业和医疗应用中颇具吸引力。然而，传统的 PEEK 金属化方法往往会导致质量控制差、沉积速率低和成本高。由于其相对温和的操作条件和高产量，冷喷涂是快速且廉价地生产聚合物金属复合材料的一种有前途的潜在替代方案。在本研究中，我们研究了由不同比例的 PEEK 粉末和铜片组成的金属聚合物复合原料在 PEEK 基材上的沉积特性。铜-PEEK 粉末共混物通过手动混合和低温研磨（低温研磨）制备，主要产生具有涂覆 PEEK 颗粒表面的微米级铜域的复合颗粒。该过程非单调地影响混合材料冷喷涂中存在的多种沉积机制的相对优势和长度尺度。在低压冷喷涂中，由于铣削，沉积物在沉积效率和成分方面表现出显着变化，这些特性的改善在铜含量较低时最为显着。在扫描电子显微镜下，PEEK 中名义上含有 30 vol.% 铜的低温研磨混合物的沉积物在扫描电子显微镜下表现出最小的孔隙率、粉末成分的完全保留以及所有测试样品中最高的沉积效率。值得注意的是，纯 PEEK 和纯 Cu 在与这种 30 vol.% Cu 混合物相同的温和条件下都没有有意义的沉积，这表明由局部沉积相互作用的相对平衡（例如，硬-软、软-软等）。旨在优化这种平衡的有意粉末和工艺设计可能会促进冷喷涂金属化应用。