The correlation between the surface morphology of zinc films electrodeposited from various solutions and their laser beam energy absorption rates have been investigated by SEM, surface roughness measurement and the laser flash method The laser flash method revealed that fan shaped zinc films electrodeposited from sulfate solutions containing surfactants showed the greatest energy absorption rate, and the rate for fan shaped zinc films increased with increasing surface roughness These results suggest that fan shaped films are suited for laser treatment
Diamond particles and films can be synthesized from vapor phase using low pressure CVD, but to obtain films, the surface of the substrate must first be scratched using diamond powder. Nucleation density depends on this pretreatment and it is difficult to keep the nucleation density and the film thickness uniform. In this study diamonds were synthesized on various transition metal substrates from methane-hydrogen reaction gas system using microwave plasma CVD. Deposits were characterized by XRD and Raman spectroscopy, and substrate surfaces were measured by XPS. It was found that films were formed on both scratched and unscratched substrates of Ru, Rh, Ir and Pt in the platinum-group metal. This deposition of films is attributed to such properties of the platinum-group metals as their catalytic effect with respect to hydrocarbons, and chemisorption of radicals, atoms, ions, and molecules.
Plasma polymerization of hexamethyldisiloxane (HMDSO) and vinylmethoxysilane (VMS) was carried out by audio-frequency (1∼20kHz) and radio-frequency (13.56MHz) glow discharge, and the effects of the polymerization conditions on film properties were studied. Films produced by RF discharge were brown in color, whereas those produced by AF discharge were colorless and transparent. The contact angle of water was greater-typically about 100°and 75°for HMDSO and VMS films polymerized by AF discharge than for those polymerized by RF discharge. In films polymerized by RF discharge, the monomer structure was destroyed and there were many inorganic linkages and crosslinks. Films deposited on stainless steel suppressed dissolution of the substrate in sulfuric acid solution.
Electroless nickel-tin-boron alloy deposits containing dimethylamine boron as a reducing agent were investigated to determine the effect of tin(IV) chloride on the deposition rate and on the tin and boron contents. The effect of the tin content of the deposits on their structure, resistivity, hardness and contact resistance was also studied. The basic bath composition was found to be nickel chloride 0.1mol/L, dimethylamine boron 0.051mol/L, sodium citrate 0.2mol/L and ammonium chloride 0.5mol/L. The pH was 7 (adjusted with NH4OH), the bath temperature was 90±1°C. The maximum tin content of the nickel-tin-boron deposits was found to be 18wt% and boron content decreased from 5.3wt% to 1.5wt% as tin content increased. Deposits with no tin content were amorphous, and crystallization was greater as tin content increased. The slope of the diffraction curve of Ni-Sn shifted to a low diffraction angle because of the formation of a solid phase. Hardness and electrical resistivity decreased as tin content increased. Contact resistance versus variable load was high for those deposits containing 16wt% tin, but low for all others.
Investigation of the effects of continuous precision filtration on electroless copper plating has confirmed that the extraneous deposition phenomena occurring during long-term plating are caused by insoluble particles that accumulate in the plating bath. Simulation of 5 turnovers of an aging bath indicated the presence of more than two millions particles larger than 1μm diameter per liter of bath, and that they were mainly composed of Al, Si, Fe and Na. The properties of the copper film deposited were greatly influenced by this extraneous deposition, which decreased with batch type filtration, but tend to increase with the passage of plating time. Continuous precision filtration during plating, however, drastically suppressed extraneous deposition and increased the elongation of the deposited copper film about twofold.
Various factors influencing the adhesion between glass and electroless nickel plated films were investigated. In terms of the film, it was found that the use of glycine as a complexing agent resulted in films that exhibited good adhesion. Adhesive strength also increased at lower pH and lower plating bath temperature. In terms of pretreatment, etching was important to improving adhesion. Adhesive strength was greatest when the glass was first etched with sodium hydroxide, next etched with hydrofluoric acid and then treated with methylate. Adhesion was also increased by decreasing the level of dissolved oxygen in the catalyzing treatment solution and plating bath.
The effects of plasma sprayed Al2O3, TiO2, and Al2O3-TiO2 coatings on surface properties and far infrared radiation were investigated by observation of surface roughness, measurement of relative reflection density, conductivity of the coatings, and the spectral energy distribution at wavelengths of 1.4∼14μm at 227°C. Increasing the TiO2 content of plasma-sprayed Al2O3-TiO2 coatings smoothed the surface, darkened the color of the coating, and resulted in semi conductivity and high far infrared radiation. Radiation energy increased with darkening of coating color.
Structural changes in dry-in-place chromate films at drying temperatures up to 400°C have been investigated using DTA, SIMS, XRD and XPS. DTA of the deposits from a solution containing Cr(VI), Cr(III) and PO43- species showed two distinct peaks due to endothermic (85∼200°C) and exothermic (200∼400°C) reactions. MASS analysis indicated the presence of fragments of high molecular fragments at the final endothermic stage (∼200°C), suggesting that polymerization occurs, but the polymerized films, partially decomposed at the subsequent exothermic stage (around 300°C). XPS analysis disclosed that the deposits consist of CrO3, Cr2O3, Cr(OH)3 and CrPO4 at the exothermic stage. In respect to the ratio of water-insoluble components of the deposits, however, the endothermic reaction caused a decrease in the Cr(III) species (major part) and an increase in the Cr(VI) (minor part), while in the subsequent exothermic reaction, the Cr(VI) decreased, suggesting that a deoxygenation reaction occurs.
The effect on the distribution and bonding state of Zr and O in the denaturizing layer of 3Y-TZP zirconia due to Ti-Ag-Cu active metal brazing was studied by means of EPMA, XRD, IMA and XPS. The results show that O was diffused from the denaturizing layer, reacting with the Ti active metal zone to produce TiO. The amount of O in the denaturizing layer was found to discrease, and the bonding state of Zr in the denaturizing layer changed from Zr4+ to Zr2+.
Ti alloys have poor wear resistance and gas carburizing has been applied in an effort to improve it. The surface hardness of Ti alloys was found to increase by the synergistic effect of the formation of oxides and carbides and the diffusion of oxygen and carbon during carburizing, but in terms of the depth of diffusion, the effect of carburizing was incomparably less than that of oxidation.