Advantages and disadvantages of the Metal Binder Jetting process

What are the advantages of the metal binder jetting (mbj) process?

The Metal Binder Jetting (MBJ)  is an additive metal manufacturing process that, by definition, has all the benefits of 3D printing:

 

  • Freedom of design (complex shapes and geometries, not feasible by conventional means, customization)
  • Short deadlines
  • Green technologies (energy, material consumption, reduction of stocks, reduction of assemblies, carbon footprint of manufacturing, etc.)

 

The  Metal Binder Jetting is an emerging technology with distinct advantages that make it a process for the future. It differs from other 3D printing technologies by several advantages.

Economical process for a very wide range of part quantities

First of all, Metal Binder Jetting (MBJ)  is the most productive metal additive manufacturing process on the market. Today, some MBJ machines are capable of producing up to 7 dm3 of parts per hour, which is about 30 times higher than powder bed laser melting machines.

This productivity is illustrated by a wide range of part number and a significant reduction in costs. Indeed, the  Metal Binder Jetting  adapts to the production of 1 to 100,000 pieces per year.

No printing support

Unlike LBM, the printing phase does not require manufacturing support. This means that the parts can be "stacked" in the build box. There is therefore no need for a specific machining step after the process.

Good surface condition

The surface roughness of the as-sintered parts (i.e. without any post-treatment) is approximately 6 m Ra (generally between 4 and 10 µm Ra depending on how the orientations influence the effect of the binder and the "staircase" effect). Other industrial 3D printing technologies generally give rise to surface roughness greater than 10 µm Ra, excluding post-processing. Starting from a good surface condition makes it easier to reach very low roughness levels with post-treatment steps. For example, with a simple sandblasting step it is possible to achieve a surface finish of 2 µm Ra. By combining different post-treatments, it is then possible to obtain mirror-polished surface states.

Unlike LBM, the printing phase does not require manufacturing support. This means that the parts can be "stacked" in the build box. There is therefore no need for a specific machining step after the process.

Dimensional precision and quality

The MBJ process   makes it possible to achieve a precision of the order of  ± 0.5% on the dimensional dimensions with a resolution of 35 µm.

This makes it possible to achieve a quality of detail equivalent to or better than other 3D printing technologies.

Many eligible materials

Metal Binder Jetting technology   is based on the powder sintering process. Powder sintering makes it possible to address a very wide range of materialsTo date, however, mature materials remain limited.

For example, powder bed laser (LBM) technologies can only address weldable materials.

Homogenity of the microstructure

Sintering makes it possible to obtain a homogeneous microstructure of the materials which ensures better repeatability in terms of mechanical strength.

By way of comparison, LBM technologies work with weld seams, thus rendering the microstructure inhomogeneous.

IS MBJ metal 3D printing synonymous with eco design and eco production?

Metal 3D printing technology and more specifically MBJ technology  offers both eco design and eco production thanks to the following aspects:

The ability to optimize the structure to reduce the amount of material used. (Example: lattice structure)

The use of only the necessary amount of material.

Reduced energy consumption because it consumes less energy than other technologies.

Reuse of unbound powder.

Limiting production to what is strictly necessary thanks to its speed of production.

The reduction of production steps and the resulting number of transportations.

lancement d'une impression 3D métal

Ordering a part from us is a step towards eco-design, the design of tomorrow. For more information you can download our brochure  here .

What are the obstacles of the metal binder jetting (mbj) process?

The Metal Binder Jetting is linked to certain constraints that do not make it accessible to the greatest number and may require complementary to other technologies.

Substantial investments

The  Metal Binder Jetting  is a process comprising several manufacturing steps and requiring several associated equipment (printing machine, mixer, dépoudreuse / sieving, ovens, sintering furnace, post-processing equipment). The whole system can lead to a significant budgetary investment. Thus, in order to access a process that is both industrial and competitive, the most important item of expenditure is the sintering furnace and its equipment. 

 

Regarding this aspect, the Poral company, whose core business is sintering, was able to access the  MBJ while limiting its initial investment.

 

Note that there is also a human investment to be taken into consideration because to date there are also manual steps which require operating time (management of green parts, depouding, installation for sintering, layer removal for separation of supports, …).

Important technical mastery

The sintering causes a shrinkage of the part, that is to say a reduction in volume of more than 40%. Controlling this sinter shrinkage is therefore essential to obtain parts with the right dimensions.

On certain types of parts, iterative loop tuning may be necessary to maintain tight tolerances.

Many materials still to be developed

Among the 3D printing technologies, one of the strengths of the  MBJ  is its panel of eligible materials, although at present it still knows its limits. Here you will find  the materials available today on the market in  MBJ .

 

To date, the development of materials that can be used in  MBJ  occupies a central place among machine manufacturers, technical centers and manufacturers who use this technology, such as the PORAL company  

Some types of inappropriate parts for the MBJ

In general, the  MBJ  is preferably dedicated to parts of limited size because the step of dusting green parts is tricky for those of very large size. The order of magnitude of the majority of parts made in  MBJ  fit into a cube of 100mm side with a length of up to 250mm.

The  MBJ  is also limiting for very thin wall thicknesses (less than 0.5mm) or very thick (upper than 3cm).

Certain types of parts have little or no interest in being manufactured in  MBJ  and other processes will be more appropriate, from a technical or economic point of view, for parts of simple shapes, easily machinable. This also applies to parts with tight tolerances. Although having a very satisfactory resolution and repeatability compared to other 3D printing technologies, the MBJ process   will be limited to tolerances of ±0,5%. In some cases, the combination of  MBJ  and machining can be an optimal solution. 

For more information on the constraints of this technology,  contact us  !

Why choose poral additive metal?

Why choose poral additive metal

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