Metal Binder Jetting is one of the most productive additive manufacturing technologies. However, before a printed green part can be transformed into a functional metal component, it must undergo a crucial process step: sintering.

This is precisely where one of the process’s greatest challenges lies. During sintering, the parts shrink significantly and sometimes deform under their own weight. To still be able to produce precise parts with tight tolerances, Desktop Metal has developed the simulation software Live Sinter™.

Why do Binder Jetting parts shrink?

After printing and the subsequent debinding process, the part is heated to a temperature just below the melting point of the metal powder.

During this phase, the individual metal particles fuse together to form a dense structure. It is only at this point that the desired material properties—such as strength, hardness, and density—develop.

At the same time, the voids between the metal particles close. As a result, the component shrinks. Typically, the linear shrinkage for metal components is about 20 percent. This means that a component that will eventually measure 100 mm must initially be printed with a significant amount of excess material so that it reaches the desired final dimensions after sintering.

The challenge: Every component shrinks differently

The difficulty lies in the fact that shrinkage does not occur identically for every component. The behavior depends, among other things, on:

• The geometry of the component
• The wall thickness
• The position in the sintering furnace
• The contact points
• The sintering parameters used

Overhangs, thin-walled structures, asymmetrical geometries, and delicate lattice structures are particularly critical. These areas may undergo additional deformation or sagging during sintering. Predicting this shrinkage behavior is therefore one of the greatest challenges in industrial metal binder jetting.

Live Sinter™ : Virtual sintering before the actual sintering process

To solve this problem, Desktop Metal has developed the simulation software Live Sinter™.

The software simulates a component’s behavior during the sintering process even before printing.

It takes various physical factors into account, including:

• Gravitational forces
• Frictional forces
• Material properties
• Thermal stresses
• Geometry-dependent deformations

Based on these calculations, the software predicts how a component will deform during sintering.

Negative Compensation Instead of Post-Processing Correction

The real highlight of Live Sinter™ is that the predicted deformations are specifically compensated for.

Instead of printing the part exactly to its target geometry, the software generates a deliberately deformed green part.

A typical example:

If an overhang sags downward during sintering, it is deliberately bent upward in the CAD model or in the green part.

After sintering, the actual deformation compensates for this pre-deformation, so that the finished component achieves the desired geometry.

The simulation therefore uses what is known as a negative offset, which takes the expected deformations into account even before printing.

The Path to Mass Production: Printing, Sintering, Scanning

For industrial mass production, a one-time simulation is often not enough.

That is why dimensional accuracy is optimized through an iterative process:

• Print
• Sinter
• Scan
• Update Simulation
• Print Again

By incorporating actual measurement results, the simulation can be continuously improved.

This data-driven approach enables increasingly accurate predictions of shrinkage behavior and significantly reduces the effort required for physical iterations.

Precision Measurement with ZEISS 3D Scanners

AM Pioneers uses ZEISS optical measurement technologies to capture the actual geometries of components.

For components up to about the size of a fist, the ZEISS GOM Scan 1 is used. The high-resolution 3D scanner generates precise point clouds and enables a direct comparison between the target and actual geometries.

The scan data obtained is then integrated into the optimization process and serves as the basis for further improvement of the simulation models.

For more information about the scanner used, click here:

https://am-pioneers.com/en/gom-scan-1/

What levels of accuracy are possible?

Through the combination of binder jetting, live sintering simulation, high-precision 3D measurement technology, and iterative process optimization, tolerances of up to ±0.15 mm can be achieved, depending on the part geometry. This makes binder jetting an attractive option even for demanding production applications that require both high volume and precise part geometries.

Depending on the part geometry, tolerances of up to ±0.15 mm can be achieved.

This makes Binder Jetting an attractive option even for demanding production applications that require both high production volumes and precise part geometries.

Conclusion

Shrinkage during sintering is one of the biggest challenges in metal binder jetting. Without appropriate compensation strategies, many parts would fall outside the required tolerances after sintering.

With Live Sinter™, Desktop Metal offers a powerful simulation solution that predicts deformations even before printing and automatically compensates for them. Combined with precise 3D measurement technology and a data-driven optimization process, this enables the cost-effective mass production of dimensionally accurate metal parts.

For companies looking to adopt binder jetting as a production process, sintering simulation is therefore a crucial step toward achieving reproducible mass production.

Would you like to learn more about Live Sinter?

Then please feel free to contact us—we’ll be happy to advise you personally.

Frederik Nussbaumer
Head of Sales
+49 172 4059105
frederik.nussbaumer@am-pioneers.com