In recent years, it has become possible to use laser beams and electron beams to 'print' engineering objects with complex shapes that could not be achieved by conventional manufacturing. The additive manufacturing (AM) process, or 3D printing, for metallic materials involves melting and fusing fine-scale powder particles -- each about 10 times finer than a grain of beach sand -- in sub-millimeter-scale 'pools' created by focusing a laser or electron beam on the material.
