Mechanical properties of oxide based materials could be improved by nanocomposite processing. To investigate optimum route for fabrication of nanocomposite enabling mass production, high energy ball milling and Pulse Electric Current Sintering (PECS) were adopted. By high energy ball milling, the -based composite powder with dispersed Cu grains below 20 nm in diameter was successfully synthesized. The PECS method as a new process for powder densification has merits of improved sinterability and short sintering time at lower temperature than conventional sintering process. The relative densities of the -5vol%Cu composites sintered at and with holding temperature of were 95.4% and 95.7% respectively. Microstructures revealed that the composite consisted of the homogeneous and very fine grains of and Cu with diameters less than 40 nm and 20 nm respectively The composite exhibited enhanced toughness compared with monolithic . The influence of the Cu content upon fracture toughness was discussed in terms of microstructural characteristics.

This study was carried out to investigate the possibility whether Metal Injection Molding (MIM) process could be applied to 95wt.%W-3.5wt.%Ni-1.5wt.%Fe heavy alloy in order to obtain an intricate shape. Methylcellulose was used in the injection molding for binder. was added in solvent substituting Fe powder and was doped on W-Ni premixed powder. When was added in solvent, the binder separation occurred for injection molding so that the matrix content was changed. Such problem was solved when was doped. In this study. the debinding process did not affect residual carbon content. The sintered microsouctures as addition methods of Fe element and the sintering temperature from to , which are around the temperature of liquid phase formation, were observed.

Sintering kinetics of ball-milled was studied with the addition of Ni. powder with the average particle size of 1 was obtained from ball-milling of 10 powder. Small amount of Ni was added to the ball-milled powder by salt solution and reduction method. The powder was compacted into cylindrical shape at 200 MPa and isothermally sintered in a atmosphere at the temperature range of 1100~ for 3~600 minutes. The changes of linear shrinkage and sintered density were monitored as a function of sintering time. The microstructure was observed by using optical microscopy and scanning electron microscopy. Phases were identified by X-ray diffratometer and electro-probe micro analysis. Sintering kinetics of Ni-added powder was compared to as-milled powder and the apparent activation energy was calculated from Arrhenius plot.