What post-processing steps are typically required for WAAM aluminum parts?

Machining and Dimensional Refinement

WAAM aluminum parts typically require precision machining as a primary post-processing step due to their coarse bead geometry and higher surface roughness compared with powder-bed processes. CNC machining is used to achieve final tolerances, flatness, sealing surfaces, and interface geometries. For components integrated into critical assemblies in sectors such as aerospace or power generation, machining may remove several millimeters of material to ensure dimensional accuracy and repeatability.

Heat Treatment and Stress Relief

Because WAAM introduces high heat input over long deposition times, residual stresses can accumulate within the aluminum structure. Stress-relief heat treatments are commonly applied to stabilize the microstructure, prevent distortion during machining, and enhance mechanical properties. For alloys such as AlSi10Mg, aging or solution-treating may be used to increase strength and homogenize the material.

Surface Conditioning and Polishing

WAAM surfaces are typically rougher than SLM or DMLS builds, so additional surface preparation may be required. This may include sanding, grinding, bead blasting, or polishing depending on the functional requirement. For aerodynamic or fluid-flow components, smoother surfaces help reduce turbulence and increase performance, making surface conditioning essential.

Non-Destructive Evaluation and Quality Assurance

Critical WAAM aluminum structures often undergo non-destructive inspection to verify integrity before final use. Techniques such as X-ray, ultrasonic testing, and metallographic sampling help detect voids, lack-of-fusion regions, or thermal-cycle-related anomalies. Advanced material testing and analysis ensures the final part meets mechanical and structural requirements, especially for aerospace-grade applications.

Final Assembly and Functional Processing

Depending on the application, WAAM components may require coating, anodizing, or sealing treatments to increase corrosion resistance and durability. After all machining, heat treatment, and inspection steps are complete, parts are assembled with mating hardware and prepared for real-world operational testing.