Mechanical Engineering - Workshop Technology - Discussion

The correct answer is Option B. I agree with the given answer.

Ref: R.S. KHURMI.

What is padding?

Be aware cheplets only support the core.

Padding on which chills rests and used to transmit the cooling effect to bottom of the casting.

I think D is the answer.

Chaplets are used for supporting cores while chills are used for used for increasing directional solidification.

Chaplets are used to support the core and also doing the function of directional solidification. I think the answer D.

D is the answer. All improve solidification.

The two thick portions of the casting have been provided with risers. The cooling of this casting will initiate from thin section and move towards the heavier sections.

For the production of a sound casting, the temperature gradients should be such that no part of the casting remains without metal during the full solidification cycle.

For this, the thinner section should be tapered towards heavier sections to change the progressive solidification to directional solidification.

This tapering of thinner section towards thicker section is known as 'padding'. However, this will require extra material. If padding is not provided, centre line shrinkage or porosity will result in the thinner section.

What is meant by sound casting?