Comparing Metal 3D Printing Technologies

Metal FFF is the most accessible and safe metal additive manufacturing technology on the market today.

How Metal FFF Works

This process uses bound powder feedstock made from metal injection molding media (metal powder bound together in waxy polymers). It uses a debinding system and a sintering furnace.

Metal FFF is a three step process. It uses bound powder and sintering, a high energy process that turns 3D printed parts using a metal powder media fully into a solid metal:

Differentiators

• Affordability. Ownership of a metal FFF printer is a significantly lower investment to own and operate than other metal printers.

• Safety. Metal 3D printer filament consisting of bound powder is relatively safe to use, and machines can be used effectively with minimal training and PPE.
• High first part yield. This is accomplished by using a bulk sintering process, which introduces fewer internal stresses than selective sintering.
• Wide material availability. In the future, there is potential for even broader future state compatibility. Industrial 3D printer metal types may include exotics and alloys.

Considerations

• Not optimized for solid parts. Typically, the machines print parts with closed cell infill. While metal FFF can print solid parts, this can either lead to increased print times or limit the variety of parts that can be manufactured.
• Near net shape parts. While parts can be post-processed to hit tight tolerances if needed, the metal FFF process typically prints near net shape parts.

Current Outlook

Metal FFF is rapidly maturing, with machines still becoming more capable and reliable. New features continually expand the application base. Many industries are tapping into cutting edge applications with metal FFF.

Long Term View

As metal FFF continues to mature, more materials and capabilities will continue to diversify the applications the technology can be used for. Metal FFF printers will become a regular fixture in manufacturing facilities due to their affordability, accessibility, and versatility when 3D printing metal parts with complex designs.

How Powder Bed Fusion Works

A laser mounted on a gantry traces the path of a given layer, precisely fusing the metal powder together.

1. A powder distribution system pushes a new layer of loose powder over the forming part.

2. The laser fuses the next layer, and the process repeats.

3. After printing, parts are de-powdered and post processed as needed.

Differentiators

• Can print specialized parts. This includes ultra-complex geometries, large parts, and large fully dense parts.
• Mature technology. As a result, there is a large material selection and several industry players offering a wide selection of machines.

Considerations

• Price. Powder bed fusion remains expensive, and metal 3D printer price tags for this technology are usually upwards of $500K to acquire and install.
• Operations. Requires a skilled operator to run, significant isolated space on a manufacturing floor, and expensive personal protective equipment (PPE) and facilities modifications. These increase the metal 3D printing cost.
• Dialing in on refined parts. Complex 3D printed metal parts will require many iterations to get a successful and accurate print. The process yields internal stresses, which can lead to cracking and deformation. High-quality parts can be printed once printing and design parameters are dialed in, however.

Current Outlook

Powder bed fusion remains the market leader in the metal 3D printing industry. There are a small number of leading industry players with advanced capabilities, and a class of new entrants attempting to fulfill a specific niche or offer a more cost competitive solution. Industries known for ultra specialized, high-performance applications have led the way in adopting powder bed fusion — including aerospace, automotive, and medical.

Long Term View

It is expected that broader adoption will drive even more innovative applications of powder bed fusion technology. As more industries start to leverage this 3D metal printing technology, more distinct applications will emerge. Increased competition will help drive more accessible machines.

Binder jetting uses specialized liquid polymer binders to form parts by adhering loose metal together. This process creates lightly bound parts that can be sintered in batches. Binder jetting, which is an emerging technology, has great potential and is a developing technology to watch.

How it Works

Binder jetting uses a two-step processes, featuring loose powder and post-print sintering:

1. During this 3D metal printing process, an inkjet-style print head precisely deposits a specialized binder on a bed of metal powder. After each layer is printed, the machine deposits more powder on top in a similar manner to powder bed fusion, repeating the print and spread process until parts are built.
2. The fragile parts are first carefully depowdered and then sintered, burning away the binder and fusing them together into fully metallic parts.

Differentiators

• Fast print speeds. Printing process is extremely fast and can fabricate many parts simultaneously.
• Precision. Precise inkjet heads lend well to creating complex parts and intricate features.

Considerations

• Safety and handling. Use of loose powder carries safety and handling concerns.
• Price. Minimum acquisition cost is at least $300K. Prices can go upwards of $2M.
• Part porosity. This process has not been proven to have reliable and repeatable mechanical properties on a broad scale.
• Part size and design constraints. Much is still unknown about the size and complexity of parts that binder jetting machines can effectively produce.
• Durability of green parts. After printing, the 3D printed metal strength is very low, which can potentially impact throughput and part constraints.
• Repeatability. If you can 3D print metal parts accurately and repeatedly with this technology is an unanswered question.

Current outlook

Binder jetting is still a developing technology, with only a few manufacturers in the space. While major players are investing in the technology, there are not many actual users.

Long Term View

Some industry analysts predict that binder jetting might be the future of mass production when 3D printing functional parts in metal. However, these projections depend on whether manufacturers find answers to the key technical questions facing the process.