The composite plating codeposition mechanism is important to control the volume fraction of particles embedded in plated films. Effects of the plating bath fluid flow on particles adsorbed onto a deposition frontier must be considered because particle embedding occurs during agitation. For this study of fluid flow effects using a rotating disk electrode（RDE）during rotation at 0-1200 rpm, we prepared diamond particles of various diameters with a homogeneous surface state. Dependence of the volume fraction of embedded particles on the rotation rate was investigated. Results show that the volume fraction of 5 nm and 20 nm diameter particles increased concomitantly with the flow rate because mass transport was promoted. In contrast, 100 nm, 200 nm, 500 nm, and 1000 nm diameter particles decreased concomitantly with increase of the flow rate. We inferred Magnus force as the factor which decreased the volume fraction of the particle in this case. The force was estimated as sufficiently stronger than gravity and buoyancy. Accordingly, that force dominated the codeposition process for particles with 100 nm or greater diameter.
Internal stresses of electroplated Ni-P alloys and electrolytic hydrogen charging to the deposits were investigated using a spiral stress contract-meter technique. The current density increased the internal stress of the deposit, but the bath temperature decreased it. Internal stress depends on the P content of the Ni-P alloy deposits. Deposits containing more than about 20 at% P are stressed compressively, whereas those with lower P content undergo tensile stress. Effects of hydrogen penetration into and escape from deposits on the stress of Ni-P alloy deposited spirals were examined in terms of the electrolytic hydrogen charge, which led to classification into two groups. The first group showed great change of stress by the hydrogen charge and showed tensile stress under electrodeposition. The second group showed no change of stress by the hydrogen charge. They show compressive stress that depends on the hydrogen diffusion constant of the deposits. Hydrogen incorporation, its trapping in the deposits, and its subsequent escape under electrodeposition play important roles in the internal stress of Ni-P alloy electrodeposits.
Because of their high hardness, wear resistance, corrosion resistance, and oxidation resistance, CrXAlYN protective coatings with differing X and Y values are used widely for cutting tools, slide members, and mechanical components. To enhance these properties further, Si atoms were incorporated to CrXAlYN with metal ratios close to the phase boundary separating cubic and hexagonal phases. The CrXAlYSiZN maintained its NaCl-type cubic structure without hexagonal phase segregation. The maximum value of microhardness was 38 GPa at Z＝0.14, where a lower friction coefficient was obtained because abrasion progression was prevented. Thermogravimetric analyses showed that oxidation resistance at 800-1000 ℃ was improved by increasing the Si contents. The flank wear of CrXAlYSiZN-coated cutting tools was lower than that of non-coated tools. This paper presents surface properties such as microstructure, microhardness, tribological properties, oxidation resistance, and tool wear behaviors of CrXAlYSiZN synthesized from alloy targets using radiofrequency magnetron sputtering.