Ni-Fe alloy shots (Ni-50% Fe) in a titanium basket were used as the anode for the electrodeposition of bright Ni-Fe alloy coatings from a dilute Watts type bath.
Active dissolution of the Ni-Fe alloy anode in the plating bath was observed; however, the surface roughness of the anode increased slightly with increases in plating time. The anode efficiency was found to be close to 100% during prolonged electrolysis. Continuous electrolysis using the initial nickel plating bath and Ni-Fe alloy anode for 24 hours at 5A/dm² resulted in an increase in Fe²⁺ and a decrease in Ni²⁺ in the bath leading to a gradual increase in Fe content in the Ni-Fe alloy deposits.
The hardness of the Ni-Fe alloy deposits obtained at pH 3.2 and 50°C was found to be 520-560Hv when Fe content was 12-38wt%. Microscopic observation of the alloy deposits revealed that the bright Ni-Fe alloy coatings had a banded microstructure. Effects of the Fe content on the X-ray diffraction profiles of the Ni-Fe alloy deposits obtained was also examined.
These results suggest that the metallurgically produced Ni -Fe alloy shots are acceptable anode material for the electroplating of Ni-Fe alloy coatings.

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The influences of the median size of SiC particles, current density and SiC concentration in slurry on the adhesive wear resistance of Ni-SiC composite coatings electrodeposited from a Watts type bath were studied. Complex behavior of the Ni-SiC electrodeposited composite coatings was observed in wear resistance tests, and no relationship was observed between wear resistance and the preparation parameters. It was found that SiC particles co-deposited in the Ni matrix seemed to have a definite particle size (1-2.5μm) regardless of the median size of the SiC particles used.

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Recently, the need has increasingly been felt for a non-destructive, rapid and precise method of testing, which can be used to measure the thickness of functional film. Use of the microscope and eddy-current instrument recommended by JIS H8680, however, produces unsatisfactory test results for thicknesses below 2μm.
Thickness of anodic oxide films and chromate coatings was therefore measured using interference fringes obtained by spectrophotometer, and the results obtained were compared with those obtained by microscope and TEM in terms of precision and measurement limits. The thickness test results obtained for sulfuric film and chromate coating using the spectrophotometer were good, with mimits for the thickness test of 0.14μm on sulfuric film (n=1.6) and 0.11μm on chromate coating (n=2.0) at wavelengths from 200 to 2500nm, where n is the refractive index.

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For the purpose of imparting adhesive properties to electroplated zinc surfaces, a trial has been conducted to control the roughness of the deposit surface. It was found that the addition of DTAC (dodecyltrimethylammonium chloride) cation and/or POELA (polyoxyethylenelaurylamine) nonion to the zinc sulfate bath yielded a “fan-shaped” zinc deposit, with a surface unevenness of 7-8μm height. Although POELA is nonionic, it behaved as a cationic surfactant, like DTAC. X-ray diffraction revealed that the fan-shaped zinc deposit was aligned perpendicular to the substrate, which had (1010) preferred orientation. The surface morphology of the fan-shaped zinc deposit has a very close resemblance to that of the zinc phosphate coating that was used prior to coating paints. The adhesive properties of the fan-shaped zinc surface and the zinc phosphate coating in regard to painted coatings were investigated using the Erichsen test, and it was found that the fan-shaped zinc deposit showed excellent adhesive properties nearly equals to those of the zinc phosphate coating. The results are explained in terms of the anchoring effect, which arised from the surface unevenness of the zinc deposits.

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