Metal 3D printing is increasingly becoming a crucial technology in various industries due to its ability to produce complex parts with high precision. However, to achieve optimal product quality, the post-processing steps play a critical role. 

This article delves into the post-processing workflow for 3D printed metal products, from removing excess powder, surface finishing, to important considerations that ensure the product meets mechanical and aesthetic requirements.

Post-Processing Steps for Metal 3D Printed Products 

Post-processing is an essential step to ensure that 3D printed products meet quality, mechanical performance, and aesthetic requirements. Below are the basic steps in this process: 

1. Powder removal

After printing, the product often has residual metal powder from the printing process. This powder needs to be removed using methods such as compressed air, brushing, or vacuuming.

Vacuum excess metal powder after printing

2. Heat treatment

Metal 3D printed products often undergo heat treatment to relieve residual stress in the metal structure and improve mechanical properties like strength and hardness. This process can include steps such as annealing, quenching, tempering, etc. During heat treatment, the printed models remain attached to the build plate along with support structures to ensure that the models are securely anchored and do not deform during stress relief. 

3. Separating the metal prints from the build plate 

After heat treatment, the parts are cut from the build plate using a bandsaw for softer materials like aluminum or copper, or wire electrical discharge machining (EDM) for harder materials like titanium, stainless steel 316L, Inconel, etc. 

4. Support removal 

Support structures printed along with the product to maintain shape during printing need to be removed after printing. This is typically done using cutting tools or manually.

The support structure can be removed by hand or machine

5. Surface treatment 

To achieve a smooth surface and remove minor defects, the product often undergoes surface treatments such as grinding, polishing, or sandblasting. The goal is to improve aesthetics and prepare for further finishing steps.

6. Additional machining

For parts requiring high precision or complex details that cannot be printed directly, additional machining may be needed, such as milling, turning, or drilling.

7. Quality inspection

After completing the post-processing steps, the product undergoes thorough quality inspection. This includes checking dimensions, geometry, and mechanical properties to ensure the product meets technical specifications. 

8. Coating or final treatment 

Finally, the product may receive a protective coating, such as painting, galvanizing, or anodizing, to protect against corrosion or enhance aesthetics. 

9. Assembly 

For parts that are part of a complex system, post-processing may also include assembling them together to create the final product.

Important Considerations in Post-Processing 

The post-processing workflow for metal 3D printed products depends on several factors related to the characteristics of the product. These characteristics will determine the specific post-processing steps required to achieve the desired quality. Below are some key factors affecting the post-processing workflow: 

1. Material 

- Type of material: Different metals, such as aluminum, stainless steel, titanium, or copper alloys, require different processing methods. For example, titanium often requires careful heat treatment to avoid brittle phase formation, while aluminum may need strict temperature control to maintain mechanical properties. 

- Thermal and electrical conductivity: Products requiring high thermal or electrical conductivity may need special surface treatments to optimize these characteristics. 

Read more: ALL ABOUT 3D PRINTING MATERIALS: METAL AND CERAMICS

2. Geometry complexity 

- Support structures: Products with complex structures often require support structures during printing, and removing these supports may require different post-processing methods, such as mechanical cutting or using automated support removal machines. 

- Complex surfaces: Products with complex surfaces or small holes may require special surface treatment techniques such as sandblasting, electropolishing, or abrasive flow machining to smooth out hard-to-reach areas. 

3. Size and thickness of the product 

- Large size: Large metal 3D printed products may face issues with uniform mechanical properties, thus requiring more uniform and prolonged heat treatment to reduce residual stress. 

- Wall thickness: Products with thin walls or uneven thickness may require different surface treatments and temperature control during heat treatment to avoid warping or cracking. 

Read more: DESIGN FOR 3D METAL PRINTING: 2 SUCCESSFUL AND COST-SAVING CASE STUDIES

4. Surface finish requirements 

- Surface roughness: If low surface roughness is required, methods like grinding, polishing, or electropolishing may be used. 

- Aesthetics: For products requiring high aesthetics, techniques like anodizing, painting, or coating may be applied after the basic processing steps. 

5. Mechanical properties required 

- Tensile strength, hardness, and ductility: These requirements may necessitate special heat treatment processes, such as quenching, tempering, or age hardening. 

- Wear resistance: If the product needs high wear resistance, processes such as surface hardening or protective coating may be required. 

6. End-Use application 

- Medical industry: Medical products may require stringent post-processing to ensure hygiene standards, including mechanical polishing and sterilization. 

- Aerospace: Products for the aerospace industry often require non-destructive testing (NDT) and surface treatment to ensure no minor defects. 

- Automotive industry: For automotive parts, dimensional accuracy and mechanical properties are critical, requiring precise machining after printing. 

7. Functional requirements 

- Heat resistance: Products that need to operate in high-temperature environments may require heat treatment or heat-resistant coating. 

- Corrosion resistance: If the product will be exposed to corrosive environments, surface treatment like plating or applying anti-corrosion coatings may be necessary. 

Depending on these factors, the post-processing workflow will be customized to ensure that the final product fully meets the technical and quality requirements. 

Read more: 5 DANGEROUS MISTAKES AND SOLUTIONS WHEN USING METAL 3D PRINTING TECHNOLOGY

Contact Vinnotek today for detailed advice on metal 3D printing solutions and professional post-processing services to bring your creative ideas to life! 

CONTACT INFO: 

☎Phone number: (+84)905300382 

📩Email: sales@vinnotek.com 

💻Website: https://vinnotek.com/ 

⚡LinkedIn: https://tinyurl.com/VINNOTEKlinkedin 

⚡Facebook: https://tinyurl.com/VINNOTEK