In which method does thermal energy help in shaping the material without reaching its melting point?

Sintering is a method where thermal energy is used to shape materials, typically powders, without reaching their melting point. In this process, the heat causes the particles to bond together through diffusion, which allows for the densification of the material while retaining its solid form. This is particularly useful in ceramics and metal part fabrication, as it enables the creation of strong, solid structures from powder without fully melting the components.

Using excess heat allows for the alteration of the microstructure and improvement of mechanical properties without the challenges that come with melting, such as changes in shape or composition. In contrast, other methods like melting require materials to reach their liquid state before they can be molded or shaped, which distinguishes sintering as a viable alternative when working with high-temperature materials that do not easily melt.