Every part created through laser powder bed fusion (L-PBF) technology must go through post processing. Some of these post-processing options are standard and applied to every part. Other processes are optional yet can have a significant effect on the appearance and functionality of a part. This guide highlights the different post-processing options available when creating metal parts through additive manufacturing.
Removing supports from a part created with L-PBF is a standard process. It's also a manual process. First, the part is cut from the build plate, typically with a bandsaw or a wire-eroding machine. Next, the supports are removed using tools (such as a hammer, chisel, tongs, or grinders). This can be a time-consuming and labor-intensive process, but it's also a necessary one.
This process highlights the need for optimized designs. The best additive manufacturing designs limit or outright eliminate the need for support structures. A surface where support was attached tends to be rough and needs to be manually smoothed.
Once this grinding is complete, the media blasting process can begin.
When to use this: Always when support is printed
Media blasting is a standard process included in any order from the MakerVerse platform. During this process, also known as sandblasting, corundum is applied to the part at high pressure. The primary function of this process is to clean a surface or to smooth scratched or marked surfaces. Corundum comes in various sizes, so it's possible to achieve the desired level of polish or roughness, depending on what's needed.
When to use this: Always
Computer Numerical Control (CNC) machining is a computerized manufacturing process. Software is programmed to determine the movement of different factory tools, such as mills, CNC routers, lathes, and other machinery. The CNC process offers dimensional stability, low surface roughness, and broad flexibility through these pre-programmed movements.
On the MakerVerse platform, CNC machining requires an additional drawing for our engineers and the production to assess the work required.
When to use: If higher feature tolerances are needed
Learn more about optimizing designs for Laser Powder Bed Fusion with this guide.
Some materials require heat treatment at completion or before continuing with other post-processing options. That's because L-PBF technology can cause internal stress when printing a part. Once the part is separate from the build platform, the internal stress might cause deviations or, worst case, part failure.
A stress relief heat treatment is often recommended. First, the material is heated to the required temperate. Once that temperature is maintained for a specific time, the material is cooled back down. Once the process is complete, the material properties change with less stress, improved elongation, and better fatigue.
For additional options, check out the datasheets for our materials to see how the hardening process or solution annealing can change the material properties significantly.
When to use: When special mechanical properties are required - such as high-strength hardened parts with very low elongation (e.g., tool steel applications)
Quality measurements don't change the properties of a part, but this can be an invaluable process that ensures that the part is printed exactly as expected. There are several quality measurements available on the MakerVerse platform.
Optical 3D Scan: High-quality stereo cameras compare the original design geometry with the finished part. This option is ideal for fast lead times.
Tactile – CMM: A coordinate measurement machine (CMM) precisely measures a part to see if there are any deviations between the finished part and the original design. Lead times are longer than 3D scans, but the measurements are more precise. This is especially recommended for CNC machined parts.
Surface Roughness: A sensitive stylus measures the roughness of a part's surface. Best performed when the statistical deviations of a surface from the ideal form are required.
Computer Tomography: Think of this as an X-ray of the part. A full 3D measurement of internal material properties using a computed tomography scanner. This should be performed when the part's internal properties must be checked against defects, errors, pores, inclusions, or voids.
When to use: Whenever in-depth quality control is needed – especially of internal features. Also, before sourcing a larger batch of parts.
When creating parts using L-PBF or any other additive manufacturing technology, choosing the best post-processing options is a critical step. These options affect the appearance, functionality, and integrity of the final part, so be sure to give proper attention to potential post-processing options.