Abstract
Dimensional tolerance of complex P/M parts is improved by uniformly filling powders in a die cavity. In our previous study, the powder behavior in filling the die cavity was investigated using a visual apparatus. It was clarified that the particle size segregation occurred in filling with low flowability of powders. In order to improve the flowability of powders in a feed shoe, an aeration powder filling method has been developed by blowing a small amount of nitrogen gas into the feed shoe. The effect of aeration powder filling was confirmed using the visual apparatus. The decreasing of particle size segregation and the shortening of the filling time by improving the flowability of powders were obtained even in the case of thin die cavity filling, compared with the conventional gravity filling.
