For the DMD (Direct Metal Deposition) process, metal powder (50 µm to 150 µm) or wire is introduced into a laser beam, where it is melted and deposited layer by layer. The layer thicknesses are up to 2 mm. The process is also very well suited for repairing complex and expensive components, e.g. in the aerospace industry. With the DMD process, it is possible to produce components from different powder materials (multi-material components) by simply changing the feed tank or the wire coil. Depending on the requirements, different areas of the same component can thus be provided with adapted material properties, for example with wear-resistant surfaces, tough bulk properties and corrosion-resistant channels.

Compared to laser melting in a powder bed, the DMD process is able to work up to 10 times faster and produce larger components. However, the finest lattice structures or component details cannot be implemented with this process – this is already evident with the metallic DIRECT METAL DEPOSITION (DMD) powder used, whose ideal particle size of 50 µm to 150 µm is more than three times larger than with laser beam melting. In production practice, the DMD process can be combined with classic ablative processes such as milling or turning. On the one hand, so-called hybrid machines allow the production of complex components with the help of additive manufacturing, but on the other hand, they can also handle the most precise milling jobs in the same setup.

Why direct metal deposition?

With laser buildup welding, new components can be built up and existing geometries can be modified. This not only allows geometric changes to be made, but also the properties of the surface can be permanently altered. Thermal conductivity, corrosion resistance and heat resistance can be increased, wear can be reduced at the same time. These functional layers can be applied selectively (partially or over the entire surface) to cost-effective base materials, producing a virtually pore-free result. Popular applications include hot and cold forming, forging and deep drawing dies.

Requirements for the coating material during buildup welding:

• abrasive wear resistance
• Corrosion/oxide resistance (even at high temperatures)
• Low coefficient of friction or high sliding friction
• Thermal conductivity
• Erosion resistance
• mechanical processing/weldability
• Toughness
• Low crack inclination/porosity

Application areas and materials

For more detailed information on our materials and applications, you can contact us here.

Construction of new geometries using aluminum alloys

The light metal aluminum is becoming increasingly important in today’s world. Due to the shortage of resources, lightweight, high-strength and isotropic materials are playing an increasingly important role. Aluminum is therefore indispensable in various industries such as aerospace, the automotive industry and mechanical engineering.

Differences to steel, such as the lower melting point, the higher reflectance, the higher thermal conductivity and the higher coefficient of expansion, but also the large delta between the melting points – oxide layer and aluminum – demand a lot from the welding process. Meeting the high quality requirements of the industries is done by high-precision, high-energy and automated processes such as laser powder buildup welding.

Problem with laser powder cladding of aluminum

The high affinity of aluminum for oxygen leads to the formation of a thin oxide layer on the surface. The melting point of the oxide layer is above 1900°C and thus more than three times higher than that of aluminum. This oxide layer interferes immensely with the welding process and leads to bonding defects. Furthermore, the solidification process of aluminum releases hydrogen, which can lead to increased pore formation.

Our solution

voestalpine eifeler Lasertechnik GmbH has developed laser buildup welding to the extent that it is able to weld components with e.g. to modify the powder material AlSi10Mg generatively or to improve the wear resistance of aluminum materials by the use of various additives. Increase materials. The range of applications for aluminum materials has thus significantly increased.

The result of the process

• Almost non-porous – < 94 – 99 % density
• Pore size < 30 μ
• Close contour structure
• High flexibility through automated process

Contact

Ms. Anna Mad
Business Development Manager
3D Printing, Coating & Components
T +43 664 615 6016
anna.mad@voestalpine.com

Contact us for more information