Post Processing for Direct Metal Laser Melting (DMLM)
A practical guide to the post-processing stages required after Direct Metal Laser Melting, from loose powder removal to final surface finishing.
Published 2024-07-17
Key findings
What's inside
- Loose Powder Removal
- Thermal Processing
- Stress Relief Treatment
- Hot Isostatic Pressing (HIP)
- Gas Nitriding
- Supports Removal
- Metal Surface Treatment
- Subtractive Finishing Process
- Additive Finishing Process
Who it's for
- Engineers working with metal 3D printing
- Product designers specifying DMLM parts
- Manufacturing professionals selecting post-processing methods
About this resource
Direct Metal Laser Melting (DMLM) parts require several post-processing steps to achieve the desired mechanical properties, dimensional accuracy and surface finish. This guide walks through each stage, including loose powder removal, thermal treatments such as stress relief, HIP and gas nitriding, support removal, and both subtractive and additive surface finishing.
Loose Powder Removal
Unfused powder is removed with brushes, hand tools, compressed air or ultrasonic cleaning equipment.
Thermal Processing
- Stress Relief Treatment: reduces residual stresses caused by rapid heating and cooling to minimize warping.
- Hot Isostatic Pressing (HIP): uses heat and pressure to improve density by removing internal and surface porosity.
- Gas Nitriding: adds nitrogen to the surface at around 520°C to increase hardness and wear resistance.
Supports Removal
Parts are separated from the build plate after heat treatment using hand tools, wire EDM or handsaws.
Metal Surface Treatment
Surface finish is improved through media blasting, machining, polishing, anodizing, electroplating, painting or PVD coating.