Types Of Casting Defects

Types Of Casting Defects

Define casting defects. Classify and enumerate in detail the different types of porosities and their causes.
Answer:

A casting defect is an irregularity in the metal casting process that is very undesirable.

Classification and Enumeration of Different Types of Porosities:

1. Those caused by solidification shrinkage:

• Localized shrinkage porosity
• Suck back porosity (irregular in shape)
• Microporosities.

2. Those caused by gas.

• Pinhole porosity
• Gas inclusions (spherical in shape)
• Subsurface porosity.

3. Those caused by air traps in mold, i.e. back pressure porosity (see Table below).