Which process uses a laser to fuse particles to produce a 3D object, commonly used for rapid prototyping?

• A. Sketches
• B. Solid modelling
• C. Stereo-lithography
• D. Selective laser sintering

Answer: (D)

This question is about an additive manufacturing method where a laser fuses powder to build a part layer by layer. In selective laser sintering, a laser scans over a bed of fine powder, fusing the particles only where the cross-section dictates. Each new layer of powder is spread on top and fused, building the object from the bottom up. The surrounding unfused powder supports complex geometries, so no separate support structures are always needed. This approach is widely used for rapid prototyping and functional parts because it can produce durable components from materials like nylon and other polymers (and in some systems, metals).

By contrast, stereo-lithography uses a laser to cure a liquid resin, not fuse powder, and the other options are design or drafting activities rather than fabrication processes. So the process described is selective laser sintering.