2017 Volume 58 Issue 4 Pages 635-640
The effect of coat permeability on mold filling for thin wall aluminum alloy castings in the expendable pattern casting (EPC) process was investigated experimentally. Thin wall aluminum alloy plates were cast by the EPC process, using eight kinds of coats with different permeabilities. The fluidity length and melt velocity were measured. The use of thin expendable polystyrene (EPS) pattern led to shorter fluidity length of melt. When the coat permeability was less than approximately 2, the fluidity length of the melt and melt velocity increased with increasing coat permeability. When the coat permeability was greater than approximately 2, even when the coat permeability increased, the fluidity length of the melt and melt velocity did not increase so much. The application of high expansion ratio of EPS pattern or high pouring temperature, led to long fluidity length of the melt. The distances of melt flow stop were predicted based on the heat transfer from the molten metal to the mold through the coat using measurement melt velocity values. The predicted values more or less agreed with experimental values for fluidity length.
This Paper was Originally Published in Japanese in J. JFS 88 (2016) 192–197.