Answer:
Vgr = 0.122 = 12.2 vol %
Step-by-step explanation:
Density of ferrite = 7.9 g/cm^3
Density of graphite = 2.3 g/cm^3
compute the volume percent of graphite
for a 3.9 wt% cast Iron
W∝ = (100 - 3.9) / ( 100 -0 ) = 0.961
Wgr = ( 3.9 - 0 ) / ( 100 - 0 ) = 0.039
Next convert the weight fraction to volume fraction using the equation attached below
Vgr = 0.122 = 12.2 vol %