CAMT Study Guide 2026

The rapid solidification rates in LPBF produce fine grain structures and can create metastable phases in certain alloys, resulting in mechanical properties that differ substantially from cast or wrought versions of the same material.

Residual stress in metal AM parts arises from the rapid heating and cooling cycles during the layer-by-layer melting and solidification process. These internal stresses can cause the part to warp, crack, or distort during or after printing, potentially leading to premature part failure. Managing residual stress through design and post-processing is critical.

Direct Metal Laser Sintering (DMLS) is a powder bed fusion process specifically designed for metal alloys. It uses a high-power laser to selectively melt and fuse metallic powders layer by layer, enabling the production of dense, high-strength metal parts with excellent precision and complex geometries. Other options are for polymers or less precise metal methods.

Stereolithography (SLA) is one of the oldest additive manufacturing processes, utilizing a vat of liquid photopolymer resin. A UV laser selectively cures and solidifies layers of this resin, building the part from the bottom up. FDM uses thermoplastic filaments, SLM uses metal powders, and Binder Jetting uses a liquid binder on powder.

In Powder Bed Fusion (PBF) processes, the ability of the powder to flow smoothly and evenly across the build platform is crucial for creating uniform layers. The particle size distribution affects powder packing density, laser absorption, and ultimately the mechanical properties and surface finish of the printed part. Poor flowability or inconsistent particle size can lead to defects and print failures.

Slicing software converts 3D CAD models into layer-by-layer toolpath instructions (G-code) that guide the additive manufacturing machine during the build.