Understanding Metal Filament for 3D Printers

Metal filaments have expanded the scope of use of metal 3D printing. Compared with traditional metal 3D printing methods (such as metal powder bed fusion and laser sintering), metal filament printing technology is not only more economical (saving 60%-90% of costs), but also avoids the safety risks associated with metal powders, providing similar design freedom and part quality. This article will introduce the characteristics and functions of metal filaments, as well as precautions during the printing process.

Source:  https://www.raise3d.com/news/raise3d-launches-metalfuse-a-3d-printing-full-in-house-solution-using-ultrafuse-metal-filaments-from-basf-forward-am-which-allows-small-batch-production-of-metal-parts-with-full-design-freed/

What is metal filament?

Metal filament is not a simple metal color or decorative material, it is a composite filament. Metal filament is made by uniformly injecting metal particles into plastic to form a material with a high metal content. This composite material can provide both strong metal parts and chemical resistance. Unlike traditional plastic filaments, parts printed with metal filaments require two to three steps of post-processing before they can finally be transformed into complete metal parts.

Precautions during metal filament printing

Although metal filament 3D printing technology provides great design freedom for the manufacture of metal parts, it also brings some unique challenges, especially in printing accuracy and post-processing. Here are a few areas that require special attention during the printing process:

Model Design

Metal filament requires that the design follow certain proportions and structural requirements. According to MakerBot's recommendations, the aspect ratio of the model should be kept below 3:1, and the wall aspect ratio should be controlled within 6:1 to prevent collapse or deformation during debinding and sintering. In addition, the design needs to add as many support structures as possible to ensure the stability of the part during debinding and sintering.

Part Shrinkage

Due to the process of plastic material removal and metal particles being compressed during post-processing of metal filament parts, the dimensional accuracy of the print may be affected. To compensate for this, users can appropriately scale the part size in the CAD model, and the slicing software can also automatically adjust based on the known shrinkage factor.

Special Post-Processing

3D printing metal filament cannot produce strong or usable metal parts immediately from the print bed. The parts after metal filament 3D printing are usually called "green blanks". These parts are very fragile and do not have metal properties before sintering, so post-processing is required to obtain strong metal parts. Post-processing processes typically include:

Debinding: Removing polymer or binder components through heat or solvent to create a void structure within the part. This process is critical to ensuring the success of the sintering process.

Sintering: The debinded part is heated in a sintering furnace to near the melting point of the metal, so that the metal particles fuse and form a dense metal part.

The post-processing process is usually complicated, so many manufacturers provide matching debinding machines and sintering furnaces to help users complete this post-processing process. If the user does not have the corresponding equipment, you can choose the professional post-processing service of the 3D printing supplier.

Mechanical properties of metal filament 3D printed parts

Metal filament 3D printed parts have significant mechanical properties, especially in terms of strength, corrosion resistance and high temperature resistance. They are stronger than almost all plastics used in standard desktop FDM 3D printing. They are ideal for low-cost, small-batch production and non-critical parts manufacturing, especially for applications that require corrosion resistance and strong toughness, such as metal nozzles, gears and valves. But it may not be suitable for applications that are subject to extreme stress. For high-strength and high-load parts, traditional metal processing methods (such as CNC processing) may still have more advantages.

Through proper design, adjustment of print settings, and reasonable post-processing, users can obtain high-quality metal parts from affordable FDM printers. With the continuous advancement of technology and continuous optimization of materials, metal filament 3D printing is expected to be widely used in more application fields. JLC3DP provides metal 3D printing and CNC processing services, which can manufacture high-precision metal parts for you, and professional post-processing services ensure that every product meets perfect standards.