This article studies copper (Cu)-based composites alloyed with nickel (Ni) and reinforced with carbon nanotubes (CNTs) fabricated via powder metallurgy under pressureless sintering methodology and vacuum. Different compositions of matrices containing 0, 3, and 30 wt% Ni are compared after sintering at 550 and 750 °C. The formation of phases for the different compositions is analyzed by high-temperature X-ray diffraction (HT-XRD) in the solid-state range up to 800 °C, in which reduction of oxides along with the sintering can be identified. Subsequently, the matrices are reinforced with pristine multiwalled CNT (MWCNT) in contents of 0, 0.5, and 1.0 wt% prior to sintering, whose dispersion is influenced by the powder's morphology. A custom-made electrical contact resistance (ECR) setup is used to investigate the electrical behavior of the sintered samples, which, particularly, allows the identification of improvements in electrical conduction of samples containing 0.5 wt% CNT and 3 wt% Ni. A reduction in chemical incompatibilities between Cu and CNT can be attributed to the presence of Ni in solid solution.

中文翻译：

---

多壁碳纳米管增强铜镍复合材料的粉末冶金制造和电接触电阻表征

本文研究了铜 (Cu) 基复合材料与镍 (Ni) 的合金化和碳纳米管 (CNT) 的增强，这些复合材料通过粉末冶金在无压烧结方法和真空下制造。在 550 和 750 °C 下烧结后，比较了含有 0、3 和 30 wt% Ni 的基质的不同成分。通过高温 X 射线衍射 (HT-XRD) 在高达 800 °C 的固态范围内分析不同成分的相形成，其中可以识别氧化物的还原以及烧结。随后，在烧结前用含量为 0、0.5 和 1.0 wt% 的原始多壁 CNT (MWCNT) 增强基体，其分散受粉末形态的影响。使用定制的电接触电阻 (ECR) 设置来研究烧结样品的电性能，特别是可以识别含有 0.5 wt% CNT 和 3 wt% Ni 的样品的导电性改善。Cu和CNT之间化学不相容性的降低可归因于固溶体中Ni的存在。