Metal 3D Printing Finishing Processes / /
Several finishing methods can help a part achieve a professional surface finish. The finishing process can add strength, rust resistance, and metal conductivity to a part while improving its appearance. Some of the finishing processes offered by Fathom include shot peening, electrochemical polishing, CNC finishing and more.
Abrasive Blast (Grit & Ceramic)
Abrasive blasting removes imperfections, rust, or other contaminants from the surface of a part. It is often used in preparation for a coating application. Abrasive blasting methods include micro-abrasive blasting, bristle blasting, bead blasting, and more. Steel grit, silicon carbide, pumice, and other abrasive materials may be used during the abrasive blasting.
Shot peening is used to add strength and reduce the stress profile of a part. During the shot peening process, the surface of the part is hit with multiple shots which cause deformation on the part’s surface. After shot peening, the part has a compressive stressed layer.
Optical polishing is used to create a microfinish or superfinish on a surface for further processing. It is best used on projects with geometries in low quantities that are not tolerance dependent. Optical polishing is a cost-effective finishing method that provides a brilliant finish.
Electrochemical polishing produces a mirror-like finish on metal surfaces and is sometimes used to prepare a metal part for additional finishing. During electrochemical polishing, the part is placed into an electrolytic solution alongside a cathode of copper or lead. An electric current moves through the solution, smoothing the part’s surface.
Abrasive Flow Machining
Abrasive flow machining is used for deburring and to polish parts. Abrasive flow machining uses chemically inactive media. The abrasive works to polish the part and remove any unwanted material.
Electroplating adds a metal layer to the outside of a part, increasing its strength and durability. Electroplating dissolves metal in an electrolytic solution and transfers it onto the surface of the part. Some of the most common metals used during electroplating are copper and zinc.
Micro Machining Process (MMP)
The micro machining process is used to produce a mirror-like finish with great technical precision while preserving the geometries of the part. During MMP, the part is first mapped using a profilometer to create a roughness profile. The part is then moved to an MMP envelope where micro-milling cutters begin to polish the part.
CNC finishing methods can improve a part’s wear resistance, metal conductivity, strength, rust resistance and more. CNC machining can also improve the look of a part and make it easier to apply a final coating. Depending on the type of surface finish needed, finishing may involve several different methods, including powder coating, bead blasting, passivation or anodizing.