Microcapsules containing abietic acid, which is the main ingredient of the flux for the solder plating, were incorporated with tin electrodeposition. The microcapsules containing abietic acid were fabricated by the polymerization between the oil-soluble and water-soluble monomers. The incorporation of the microcapsules in the tin film was confirmed by surface observation with a confocal laser scanning microscope. Furthermore, the dispersibility of the microcapsules in the plating bath was investigated. It was found that the dispersibility of microcapsules involving fluorobenzene was superior, since the ratio of the specific gravity of the microcapsule to the plating bath was close to unity. As a result, the stable incorporation of microcapsules could be carried out by the present plating method.
A compositionally graded film (type-G film) that had Si-rich composition near a substrate of Si or Ti alloy and C-rich composition near the surface and a Si-rich monolithic film (type-S film) were prepared by the ionization deposition method using hexamethyldisiloxane and benzene as raw materials. Diamond-like carbon (DLC) films were deposited successively on to the type-G film, type-S film and the substrate directly. These are denoted in this paper as DLC/G, DLC/S and single-DLC, respectively. There was no difference among their Raman spectra, which suggested that existence of the intermediate layers, type-G and type-S films, did not affect the bonding structure of the DLC film surface. The hardness of DLC/G was 30 GPa, being about as high as that of single-DLC (33 GPa). The type-G film was about 1.4 times harder than the type-S film. X-ray photoelectron spectroscopic analysis revealed that a fairly large amount of SiC and graphite components existed on the surface of the type-G film, which increased the film hardness. In the scratching test, the critical load of DLC/G was 3 or more times grater than that of the single-DLC film, and was 1.2 or more times that of the DLC/S. The scratched mark on DLC/G was clearly different from those of other DLC films. The type-G film was proven to be effective as an intermediate layer in obtaining good adhesion between the DLC film and the substrate.
The influence of a redox active surfactant (4-Ethylazobenzene-4’-(oxyethyl)trimethylammonium bromide, AZTAB) and a redox inactive surfactant (n-Dodecyltrimethylammonium bromide, DTAB) on the codeposition of diamond particles with nickel has been investigated. A nickel bath containing DTAB did not deposit a higher amount of diamond particles with nickel, whereas the nickel bath containing AZTAB deposited more than twice the amount of the particles (45.5 vol.%) that were deposited by the former bath (21.6 vol.%). An electrochemical investigation showed that AZTAB is reduced during the nickel deposition. Therefore, it has been assumed here that the reduction of free AZTAB at the cathode surface leads to desorption of AZTAB adsorbed on the particles in the vicinity of the cathode. As a result, deposition of these particles at the cathode surface takes place before these particles are being entrapped in the layer of growing nickel. The wear resistance of the Ni/diamond composite coatings containing various volumetric content of particles was also investigated. This showed that a higher degree of wear resistance accompanied increased particle content.
Sulfate(SO42-) and hexafluorosilicate(SiF62-) ions in chromium plating bath were simultaneously analyzed by capillary electrophoresis(CE), using a chromate buffer with indirect UV-detection at 270 nm. Determination was carried out within 10 minutes by diluting the solution with water without any pretreatment. The CE method was found to be powerful technique for chromium plating bath control.