Which process involves making a solid material into a liquid, pouring it into a mold, and allowing it to harden?

The process described involves transforming a solid material into a liquid form, followed by pouring that liquid into a mold and allowing it to solidify. This is characteristic of casting, which is a manufacturing technique widely used for creating complex shapes in various materials, including metals and plastics.

Casting typically involves heating the material to its melting point until it becomes liquid. Once in this state, the liquid material can be easily poured into a mold that contains a hollow cavity in the desired shape. After allowing sufficient time for cooling and solidification, the mold is removed to reveal the finished product. This technique is particularly advantageous for producing intricate designs and shapes that would be difficult to achieve through other manufacturing processes.

In contrast, the other processes listed—molding, extrusion, and forging—do not accurately fit the description provided. Molding entails forming material into shapes using rigid molds but does not specifically emphasize the heating and pouring of liquid material. Extrusion involves forcing material through a die to create long shapes or profiles rather than pouring. Forging refers to shaping material through compressive forces, typically while it is solid rather than liquefied. Each of these methods has distinct applications and characteristics that differentiate them from the casting process.