Binder Jetting vs. Metal FFF 3D Printing

According to the SmarTech Analysis report “Bound Metal & Metal Binder Jetting AM 2022,” metal binder jetting and bound metal extrusion technologies will produce $54 billion in parts through 2030. Bound metal is considered by the additive manufacturing (AM) market research firm to be the fastest growing segment in the industry.

While they are categorized together, metal binder jetting and bound metal extrusion, also referred to as metal fused filament fabrication (FFF), are two distinct technologies with their own advantages, disadvantages, and applications. In this article, we’ll attempt to break them down to make those distinctions easier to understand.

Similarities: What Are Metal Binder Jetting and Metal FFF?

Whereas metal binder jetting relies on the deposition of a binder onto a bed of metal powder to create a part layer by layer, metal FFF sees the metal powder already bound together with a polymer that is then melted and extruded out of a heated print head. In both cases, the printer produces a green part that must be debound, so that the binder is extracted, and then sintered in a furnace, fusing the metal particles together into a dense, final object.

Differences: How Do Metal Binder Jetting and Metal FFF Stack up?

The similarities between the two technologies essentially stops at this shared workflow. There are numerous differences between binder jet and metal extrusion, key among which are cost and accessibility. Whereas a binder jet machine can cost upwards of $1 million, metal FFF can be performed on the least expensive of desktop 3D printers, which run about as low as $150.

A part printed with Ultrafuse® metal filament.

This means that anyone with a few hundred dollars or access to a library or makerspace can 3D print with metal. Additionally, metal FFF can be performed in a traditional environment, including well-ventilated offices and classrooms, because metal extrusion doesn’t require a great deal of space and, more importantly, doesn’t rely on caustic powders. Working with metal binder jetting can necessitate the use of ventilators and a clean room, where metals may be potentially explosive. Altogether, metal binder jetting thus requires additional infrastructure, including depowdering systems, that aren’t necessary for metal FFF.

Debinding and sintering is another story. Debinding stations and furnaces are not as accessible, nor is the experience to properly use this equipment. For this reason, metal FFF materials providers like Forward AM, the BASF 3D Printing Solutions brand for 3D printing materials and solutions, promote third-party services for performing expert debinding and sintering. In the case of Forward AM, this can be ordered through the Debinding and Sintering Order Management Portal.

The material options for metal FFF are just beginning to grow. As of now, Forward AM offers Ultrafuse® 316L and Ultrafuse® 17-4 PH. The former stainless-steel composite is ideal for tooling, jigs and fixtures, functional prototypes, and small series production. The latter stainless steel offers high hardness and mechanical strength, as well as good corrision resistance.

Other Benefits of Metal FFF over Binder Jetting

Outside of accessibility, metal FFF offers a number of benefits over metal binder jetting. For instance, while binder jetting can potentially be used to produce large batches of components, green parts are actually weaker. This typically means a limit in terms of size, wall thicknesses, and post-processing. With Ultrafuse® metal FFF, a wall thickness of no less than 1mm in the green part is recommended. More information on wall thickness can be found here.

An image showcasing Ultrafuse® Support Layer material before and after sintering. 

For metal extrusion, green parts can be polished, grinded, milled, drilled, and shipped. Thin walls and overhangs are also possible. The use of dual extrusion opens up the possibility of 3D printing with specialty support material Ultrafuse® Support Layer that creates a barrier between the support and the component so that the support can be detached from the part afterwards, without causing any mechanical impact. In contrast, binder jetting requires thick walls that so that they do not collapse under pressure, with supports nearly impossible to create unless they are printed separately.

The Metal Extrusion Market

At the moment, there are few manufacturers of metal filaments. Among them is BASF, the world’s second largest chemical company after ChemChina. The German giant manufactures a metal injection molding (MIM) material called Catamold that has been used within manufacturing for some 30 years.

As it stands, metal FFF is the least expensive way to enter the metal 3D printing space, making an ideal entry point for those exploring the possibilities. In fact, this author has been able to test the technology through a combination of metal filament and sintering bureau. Beginning with metal extrusion, it’s then possible to move onto more expensive technologies or scale up one’s own use of metal FFF.

While there is a great deal of hype around metal binder jetting, particularly as a solution for large manufacturers to mass produce 3D printed parts, metal extrusion offers its own benefits that could see large batch production take place as well. Just as polymer FFF has been leveraged for print farms, we can imagine metal FFF take a similar route.

For these reasons and more, in its “Bound Metal & Metal Binder Jetting AM 2022” report, SmarTech Analysis projects hardware sales for metal FFF to exceed $1 billion by 2030. This will likely include machines for in-house metal part prototyping, spart parts, small service bureaus, and print farms.

If you just want to try it out, order metal parts already debound and sintered from Sculpteo. Alternatively you can leverage BASF Forward AM’s great debinding and sintering network in various regions to debind and sinter your printed green parts via the Debinding and Sintering Order Management Portal.

Images courtesy of Forward AM.