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Metals. 11(4), 591 (2021)

Ag/carbon nanotube (CNT) composite films were prepared by electrodeposition from non-cyanide baths. An iodide bath and multiwalled CNTs were used. The stability of the iodide bath under ambient conditions at various pH levels was examined, along with the changes in visual appearance, pH, and triiodide ion (I-3(-)) concentration. The electrodeposition was conducted under galvanostatic conditions using iodide baths with and without CNTs. The microstructure of the Ag and Ag/CNT composite films was characterized, and the hardness, electrical conductivity, and coefficient of friction of the films were measured. The iodide bath was stable at higher pH levels under ambient conditions. The obtained Ag/CNT composite films exhibited a compact structure, and CNTs were homogeneously distributed in the interior of the deposited Ag matrix. The CNT content in the deposits increased with increasing CNT concentration in the plating bath. The hardness of the Ag/1.2 mass%-CNT composite film was 63.2 HV, which was slightly greater than that of the Ag film (60.4 HV). The resistivity of the composite film was 1.9 mu omega cm, which was slightly higher than that of the pure Ag film (1.8 mu omega cm). The coefficient of friction of the composite film was lower than that of the Ag film., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 167(12):122515 (2020)

Carbon nanotube (CNT)/Cu composite yarns were formed via a single-step electrodeposition process. A twisted CNT yarn composed of multiwalled CNTs (MWCNTs) was used. Copper was directly electrodeposited onto the CNT yarn under galvanostatic conditions using copper sulfate baths with and without additives. Four additives (polyethylene glycol (PEG), chloride anion (Cl-), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB)) that are well known as "via-filling additives" were used together. The surface and cross-sectional microstructures of the copper-deposited CNT yarns were analyzed. Copper was electrodeposited only onto the surface of the CNT yarn from the bath without additives, resulting in a copper-coated CNT yarn. By contrast, copper was deposited not only onto the surface but also into the interior of the CNT yarn from the bath with the additives. The amount of copper deposited into the CNT yarn tended to increase with increasing PEG and Cl-concentrations. The current density also affected the size and location of the deposited copper particles. When the electrodeposition conditions were optimized, copper was relatively homogeneously deposited into the interior of the CNT yarn, resulting in a CNT/Cu composite yarn. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited., Article, JOURNAL OF THE ELECTROCHEMICAL SOCIETY. 167(10):102509 (2020)

The durability of the dissimilar material joint between a steel coated with a roughened nickel plating-film and a thermoplastic resin is assessed. The roughened nickel film is fabricated by electrodeposition using carbon nanotubes (CNTs) as the roughening agent and a polyphenylenesulfide (PPS) resin as the thermoplastic resin. The plated steel and PPS resin are joined by injection molding without adhesive. The bonding strength is determined by a tensile lap shear strength test during the durability tests that includes a high-temperature and high-humidity test (85 +/- 2 degrees C, 85 +/- 2% relative humidity; 0-2000 h) and a thermal shock test (-50 degrees C-150 degrees C; 0-1000 cycles). During the high-temperature and high-humidity test, the bonding samples maintain their initial bonding strength (>40 MPa) even after 2000 h. By contrast, during the thermal shock test, although the bonding strength gradually decreases with increasing number of cycles, it remains above 20 MPa even after 1000 cycles. The mechanism of the deterioration of the bonding strength during the thermal shock test is analyzed in detail. The present joining method, which uses a roughened plating film as an interlayer, offers a way to achieve not only high initial bonding strength but also bonding durability for dissimilar material joining between steels and resins., Article, ADVANCED ENGINEERING MATERIALS. 22(12):2000739 (2020)