Titanium-based hard coatings have been developed by adding different metals to TiN in order to obtain mechanical, tribological, and thermal properties that are superior to those of TiN. In this study, Ti_1－XW_XN films were synthesized from Ti_1－X-W_X alloy targets（X＝0, 0.25, 0.35, 0.5, 0.75, and 1.0）by radio-frequency magnetron sputtering. X-ray diffraction analysis indicated that all of the prepared films were solid solutions with a NaCl-type structure, and their interplanar spacing changed as the W content（X）was varied. The microhardness gradually increased from 21 GPa（at X＝0）to 28 GPa（at X＝0.66）and then decreased to 22 GPa（at X＝1.0）. The average coefficient of friction varied between 0.4 and 0.8, and the wear track had a depth below 0.15 μm in the films with X＝0-0.66. The exothermic peak of differential thermal analysis shifted from 814 ℃（at X＝0）to 846 ℃（at X＝0.34）during dynamic oxidation. Correspondingly, the film with X＝0.34 showed the smallest mass gain during isothermal oxidation at 600-700 ℃, and its resistance against oxidation was better than that exhibited by TiN（at X＝0）. The surface properties in terms of microstructure, microhardness, tribological properties, and oxidation resistance were also characterized as functions of the W content.

Relationship between the adsorption state of organic additives and their suppressive effects on copper electrodeposition was studied. Adsorption on the electrode surface was characterized using atomic force microscopy（AFM）, quartz crystal microbalance with dissipation monitoring technique（QCM-D）, and ellipsometry. Suppressive effects of the additives were evaluated using polarization curves and electrochemical impedance spectroscopy（EIS）. Results demonstrated that suppressive effects did not always correlate with the QCM-D measured adsorption amount. Instead, the adsorption rates of the additives and the viscoelastic properties of the adsorbed films strongly influenced the suppressive effects. A cationic surfactant（hexadecyltrimethylammonium bromide, CTAB）can adsorb to the solid surface rapidly and can form a rigid film, giving the strongest suppressive effect among the organic additives investigated in this study. A water-soluble polymer（poly（vinyl alcohol）, PVA）forms a highly hydrated soft film on the solid surface and shows a weak suppressive effect. An anionic surfactant（sodium alkylbenzensulfonate, LAS）can adsorb to the solid surface, but because the adsorption rate is very low, the suppressive effect was very weak. In several nonionic surfactant systems, the adsorption amount and the suppressive effect were mutually correlated, qualitatively reflecting the similar structures of their adsorption films.

To comply with zinc effluent regulations, we investigated the influence of plating chemicals on zinc removal from zinc chloride solutions by coagulation with sodium hydroxide. Plating chemicals including ethylenediaminetetraacetic acid disodium salt（EDTA･2Na）, ammonium chloride, sodium citrate, triethanolamine（TEA）, sodium diphosphate, and potassium dihydrogen phosphate decrease zinc removal capabilities. The zinc removal capability in the solutions depends on the concentrations of additive compounds. Especially, the addition of EDTA･2Na and sodium diphosphate exert an important influence that is attributable to the complex forming reaction of zinc and EDTA･2Na. For the addition of 8.8 mg/L EDTA･2Na, removal of zinc from the solutions and exceeding the effluent regulation value of zinc was difficult. Furthermore, to reduce compounds interfering in wastewater, we examine emissions management. Results demonstrated that the drain of barrel processing increases the interfering compounds in wastewater. Plating chemicals disturb the zinc wastewater treatment.

We investigated the metal ion concentration effects on film composition of Fe-W alloy plating and tungsten deposition on the iron group metal cathode. Tungsten was deposited at a limited atomic ratio to iron group metals. Tungstate ions can be reduced to a metallic state on the iron group metal cathode by complexing with citrate ions.