LMM

Step 1

Printing

The build plate of the LMM printer sits above a reservoir of the material which consists of photopolymeric binder and an MIM grade metal powder. At the start of the process, the printer’s build platform is lowered and submerged in the reservoir of material where the light source exposes a raft layer off which the part will be suspended by its network of supports. At the completion of the first layer the build platform lifts up above the surface of the photopolymer when a levelling arm spreads and agitates the material. For all remaining layers, the previously hardened part layer returns to the photopolymer and a digital light source projects each layer onto it until the part build is complete, culminating is in a green part.

Step 2

Post Processing

The green part is then placed inside an oven where the photopolymeric binder is thermally decomposed, leaving behind only the metal powder.

Step 3

Support Removal

Manual Removal Supports are typically printed in the same feedstock and are removed after debinding/sintering; may require cutting, snapping, or machining. Soluble Support Removal Non-applicable at this stage. Manual Cleaning Note: After printing, green parts (pre-debinding) are fragile and handled carefully; supports are easiest to remove after sintering.

Step 4

Surface Finishing

Sanding / Polishing Common after sintering to refine surface finish; LMM already provides smoother surfaces than most powder-bed metal AM. Chemical Smoothing / Coating Possible for some metals (e.g., electropolishing stainless steel); coatings like passivation or nickel plating may be applied. Painting / Priming Typically used in consumer or decorative applications; requires surface preparation. Gloss / Matte Control Naturally fine matte finish; surface sheen can be adjusted with polishing or coating.

Step 5

Curing / Heat Treatment

UV / Thermal Curing UV curing is used during the printing process to solidify layers of metal slurry. Annealing / Stress Relief Essential steps post-print include: - Debinding: Polymer binder is removed in a thermal or solvent process. - Sintering: Metal particles are fused into a dense structure at high temperature.

Step 6

Assembly and Functional Finishing

Gluing or Bonding Possible for non-structural assembly; welding or brazing may be used for stronger joins. Drilling / Tapping / CNC Common, especially for fine adjustments, tight tolerances, or threaded features. Inserts / Fasteners Threaded inserts or helicoils can be added post-process; used widely in industrial assemblies.

Step 7

Special Treatments

Infiltration / Sealing Generally not required, as sintering can produce high-density parts; however, HIP (hot isostatic pressing) may be used to enhance density in some cases. Functional Coatings Commonly used coatings include corrosion-resistant or wear-resistant layers, depending on application.