Casting Defect Caused by Erosion of Sand

Erosion of sand can cause several casting defects. The most common casting defect caused by the erosion of sand is a drop. Let's understand this in detail:

What is a Drop?

A drop is a casting defect that occurs when molten metal leaks out of the mold cavity due to erosion of sand. This results in a hole or depression in the casting.

Causes of Drop

The main cause of drop is the erosion of sand in the mold cavity. This erosion can occur due to several reasons such as:

- High pouring rate of molten metal
- Inadequate venting of the mold
- Improper gating system
- Poor quality of sand used in the mold
- Lack of compaction of sand in the mold

Effects of Drop

The drop can have several adverse effects on the casting such as:

- It weakens the casting and reduces its load-bearing capacity
- It can cause leakage of fluids or gases in the casting
- It can lead to the rejection of the casting due to poor quality

Prevention of Drop

The drop can be prevented by taking the following measures:

- Using high-quality sand in the mold
- Ensuring proper compaction of sand in the mold
- Reducing the pouring rate of molten metal
- Proper venting of the mold
- Using an appropriate gating system

Conclusion

The drop is a serious casting defect that can affect the quality and strength of the casting. It is caused by the erosion of sand in the mold cavity. By taking appropriate measures, such as using high-quality sand, proper compaction of sand, and an appropriate gating system, this defect can be prevented.

The first type is mold erosion, which is the wearing away of the mold as the liquid metal fills the mold. This type of defect usually only occurs in sand castings because most other casting processes have more robust molds. ... This can be caused by a sand with too little strength or a pouring velocity that is too fast.