Question

In a certain pressing operation, the metallic powder fed into the open die has a packing factor of 0.5. The pressing operation reduces the powders to 70% of their starting volume. In the subsequent sintering operation, shrinkage amounts to 10% on a volume basis. Given that these are the only factors that affect the structure of the finished part, determine its final porosity.

Answer 1

0.2063

Step-by-step explanation:

Given data:

packing factor = 0.5

percentage of reduction of powders = 70%

Calculate the final porosity

after sintering Bulk specific volume = 0.9 * 0.7 = 0.63

assuming true specific volume = 1

packing factor = 0.5 , bulk specific volume = 2

packing factor after pressing and sintering

= 1 / ( 2 * 0.63 ) = 0.7937

hence : porosity = 1 - packing factor

= 1 - 0.7937 = 0.2063