Mechanical Engineering - Workshop Technology - Discussion

The correct answer is Option B.

Refer: R. S. KHURMI.

D is the right option.

Chill= chill are used to increase the cooling rate.

Padding= it safe restless defect or penetration defect.

D will be the correct answer.

The correct answer is: chills, chaplets, and padding.

Directional solidification in casting refers to the controlled solidification of molten metal to achieve a specific grain structure and orientation. This can be improved by using:

- Chills: Metal inserts that absorb heat and promote solidification in a specific direction.
- Chaplets: Small metal pieces that support the sand mould and help to direct solidification.
- Padding: A layer of insulating material (e.g., sand, graphite) that slows down solidification in certain areas.

Using a combination of chills, chaplets, and padding can help to:

- Control the rate of solidification
- Prevent porosity and shrinkage defects
- Achieve a more uniform grain structure
- Improve the overall quality of the casting

The other options are incorrect because:

- Chills and chaplets alone may not provide sufficient control over solidification.
- Chills and padding alone may not provide adequate support for the sand mould.
- Chaplets and padding alone may not effectively control the direction of solidification.

The specific combination and arrangement of chills, chaplets, and padding will depend on the casting design, material, and process requirements.