| Solid and liquid phase sintering behaviors of ball-milled 75W-25Cu have been studied by using a dilatometry technique. The ball-milled 75W-25Cu was prepared by high energetic ball milling under argon atmosphere of 1 atm with duration times of 50 to 400 hrs. The sintering was performed in the dilatometer under flowing hydrogen atmosphere with a heating rate of 3℃/min. To compare with the ball milled 75W-25Cu, blended 75W-25Cu was also prepared and sintered. Sintering shrinkage, dl/1, increased with increasing milling time from 50 to 400 hrs. The shrinkage versus temperature plots of the ball-milled 75W-25Cu can be divided into three regions, while for that of the blended 75W-25Cu two regions. The characteristics of ball-milled 75W-25Cu were analyzed by energy dispersive spectroscopy (EDS), differential scanning calorimeter(DSC) and scanning electron microscopy (SEM). The considerable grain growth of W particles was observed during the liquid phase sintering of the ball-milled 75W-25Cu. From these results, the solid and liquid phase sintering behaviors were discussed in terms of the size, the stored energy, and the distribution of W and Cu particles embedded in the ball-milled 75W-25Cu composite powders. (Received August 18, 1992) |
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