1. ω M / (M+2m)
2. ω M / (M+m)
3. 2ω M / (M+2m)
4. ω
ω M / (M+2m)
1. (mAω2)/2r
2. (Aω2r)/4m
3. 1/2 Aω2mrs
4. (2mω2)/Ar
1/2 Aω2mrs
1. Freeze after the casting freezes
2. Freezing before the casting freezes
3. Freeze at the same as the casting
4. Minimize the time of pouring
Freeze at the same as the casting
1. Liquid contraction
2. Solidification contraction
3. Solid contraction
4. All the above three types of contractions
Solid contraction
1. Achieve directional solidification
2. Reduce possibility of blow holes
3. Reduce the freezing time
4. Smoothen the metal for reducing
Achieve directional solidification
1. Flowability to go through a maxima
2. Permeability to go through a maxima
3. Compressive strength to go through a maxima
4. Strength to go through a maximum
Flowability to go through a maxima
1. 4:8:3
2. 1:3:3
3. 1:2:4
4. 1:2:1
1:2:4
1. Pouring temp of the liquid metal
2. Freezing temperature of the liquid metal
3. The component size
4. Coefficient of thermal contraction of solidified metal
Pouring temp of the liquid metal
1. Increase the rate of feeding
2. Quickly break off the protruding portion of the casting
3. Decrease wastage of cast metal
4. Avoid aspiration of air
Avoid aspiration of air
1. Less chance of gas porosity
2. Uniform flow of molten metal into the mold cavity
3. Greater dimensional stability of the casting
4. Less sand expansion type of casting defect
Greater dimensional stability of the casting