Ilguk Jo

Surface and Photolytic Characteristics of Ni-TiO 2 Composite Layer Electro-Plated from Non-Aqueous Electrolyte

Composite plating is a method of co-deposition of plating layer with metallic and/or non-metallic particles to improve the plating layer properties such as high corrosion resistance and photolysis of organic compounds. The properties of nickel-ceramic composite plating are significantly depend on the surface characteristics of co-deposited particles as well as the quantity in electrolyte. In this study, Ni- composite coating layer was produced by electrodeposition technique from non-aqueous eletrolyte and its surface characteristics as well as photolytic properties were investigated. The amounts of immobilized particles increased with increasing the initial particles contents in the bath. Samples electroplated with the current density of showed the significantly improved homogeneous particles distribution. The corrosion resistance of Ni- composite coating layer also improved with increaing the amounts of particles. Etched sample showed about 10% increased photolytic rate of organic matter compare to that of the non-etched.

Fabrication of CNT dispersed Cu matrix composites by wet mixing and spark plasma sintering process

Multi-walled carbon nanotube (MWCNT)-copper (Cu) composites are successfully fabricated by a combination of a binder-free wet mixing and spark plasma sintering (SPS) process. The SPS is performed under various conditions to investigate optimized processing conditions for minimizing the structural de...

Chromium carbide/Carbon Nanotube Hybrid Structure Assisted Copper Composites with Low Temperature Coefficient of Resistance

In order to explore the possibility of using carbon nanotube (CNT) to introduce and control the temperature coefficient of resistance (TCR) of metal matrix composite, relatively thick and short multi-walled CNTs (MWCNTs) were introduced in the metal matrix with in-situ formation of chromium carbide (Cr7C3) at the CNT/copper (Cu) interface. We demonstrate that incompatible properties such as electrical conductivity and TCR can be achieved simultaneously by introducing MWCNTs in the Cu matrix, with control of the interfacial resistivity using the MWCNT/Cr7C3–Cu system. High electrical conductivity of 94.66 IACS and low TCR of 1,451 10–6 °C−1 are achieved in the 5 vol.% MWCNT–CuCr composite. In-situ formation of Cr7C3 nanostructures at the MWCNT/Cu interface by reaction of diffused Cr atoms and amorphous carbon of MWCNTs would assist in improving the electrical properties of the MWCNT–CuCr composites.

Photolytic Characteristics of Ni-TiO 2 Composite Coating from Electroless Plating

Many fundamental studies have been carried out regarding waste water and hazardous gas treatments technologies using the photolysis effect of . However, a permanent use of particles immobilized using organic or organic-inorganic binders is impossible. In this study, Ni- composite coating was produced by electroless plating to trap particles in the Ni coating layer. The electroless plating was performed in the bath solutions with three different concentrations of particles : 10 g/l, 20 g/l, and 40 g/l. The surface and photolytic characteristics of the coating layer was investigated by the use of SEM, a scratch tester, and an UV-Visible spectrophotometer. The results showed that the amounts of immobilized particles and the photolytic rate of the coating increased with the initial content of particles in the electroless bath. In addition, the photolytic rate of the Ni- composite coating was remarkably promoted by etching process in 10% HCl solution.