Ablation casting

Ablation casting is a variation of a sand casting involving a soluble binder. The mold is dissolved and washed away, allowing rapid cooling of the casting.

Procedure

Ablation casting is a sand casting process that uses water to wash away the mold while the metal solidifies. This process produces castings with high mechanical properties, reduced defects, and a fine microstructure.

There are three steps in the ablation casting process:

1. Mold preparation: A mold is made from sand particles bonded with a water-soluble binder.
2. Filling: The mold is filled with molten metal.
3. Ablation: While the metal is still molten, a spray of water erodes away the mold. The water allows direct contact with the metal, which eliminates the air gap that usually forms in other casting processes.

Advantages

Ablation casting has several advantages, including:

• No fumes or dust The mold is washed away without producing fumes or dust.
• High cooling rates The water spray produces high cooling rates, which results in a fine eutectic microstructure.
• Directional solidification The water spray allows for directional solidification, which can help reduce problems with casting alloys.
• Low porosity The high temperature gradient and solidification speeds can help eliminate shrinkage porosity.

Examples

Honda used ablation casting to produce the Acura NSX hybrid supercar. Honda chose ablation casting because conventional castings would have been too brittle for the car's crush zones.