ME 477 Lecture Notes - Lecture 2: Die Casting, Porosity, Surface Tension
Document Summary
Consideration #2 is important because being kept open to atmospheric pressure adds extra pressure on the. When the rate of pouring molten metal into a mold is slow, the fluidity will be lower because the rate of cooling. Having the proper rate of heat transfer is extremely important for mold materials. Cooling too quickly could cause the material to not have time to develop the proper grain structure, lowering the material strength and other properties. If the mold material has a low coefficient of heat transfer, if will give the metal plenty of time to fill the mold and cool to its final grain structure. However, this can add an extreme amount of time to the process before the mold can be broken and the part removed. In this example, production rates would be slowed: we know that pouring molten metal at a high rate into a mold has certain disadvantages.
