VIGA Systems

Vacuum Induction Melting Inert Gas Atomization Systems for Charge Weights from 5 up to 2500 kg

ALD Vacuum Technologies GmbH is the market and technology leader for vacuum inert gas atomizers used in the production of high-quality metal powders. In addition, ALD has extensive experience in combining various melting technologies with inert gas atomization systems to address particular material requirements. The application-specific combination of melting and atomization techniques enables production of a wide range of super-clean metal powders, including super-alloys, precious metals, refractory and reactive metal powders. Our clients can choose between two main atomizer types, namely EIGA and VIGA, for charge weights from 5 kg up to 2500 kg. Customized EIGA and VIGA design variations are available to meet customer specific requirements.

ALD’s Vacuum Induction Melting Inert Gas Atomization System for the production of high-quality, spherical metal powders

Vacuum induction melting and inert gas atomization is the leading process for production of a variety of high-performance metal powders and essential for quality manufacturing of Ni-based super-alloys as well as Fe-, Co-, Cr-based and other special alloy powders. In the VIGA system, a vacuum induction melting unit is integrated with an inert gas atomization unit. The starting materials are melted using electromagnetic induction which couples electrical power into the crucible/material under vacuum or in an inert gas atmosphere. Once the desired melt homogeneity and chemical composition have been achieved, the material is poured into a tundish by crucible tilting. The fine metal stream flowing from the tundish orifice into the atomization nozzle system is subject to a high-pressure, inert-gas jet and then atomized. The combination of molten metal and gas jet creates a spray of micro-droplets that solidifies in the atomization tower and forms fine powder with spherical shape.

Powder Characteristics

Powders produced with ALD’s VIGA systems typically have the following characteristics:

  • Spherical shape
  • Good rheological flow characteristics
  • Particle size ranging from 30 µm ≤ d50 ≤ 90 µm
  • High purity
  • High flow ability
  • Low O, N, and H concentrations
  • Rapidly solidified and homogeneous microstructure

Materials and Metal powder applications

VIGA systems are the most versatile method for processing a variety of metallic elements and alloys into metal powders. Powders produced by the VIGA process are used in numerous applications highlighted below:

Materials

  • Ni-base super-alloys
  • Fe-, Co-, Cr-base alloys
  • High alloy steels
  • High purity Cu-, Al- and Mg-alloys
  • MCrAlY alloys
  • Precious metals and their alloys

Applications

  • Solder and brazing metals
  • Wear and oxidation protection coatings
  • Ultrapure reactive copper and aluminum alloys
  • Sputtering targets
  • Feedstock for additive manufacturing technologies (e.g. 3-D printing)
  • Feedstock for MIM and HIP

Markets served

  • Aviation industry
  • Power engineering
  • Electronics and chemical industry
  • Bio-medical engineering
  • Precious metal industry
  • Research and development

Large Scale VIGA Systems

ALD offers large-scale VIGA systems with capacities up to 2500 kg per batch for high-volume production of metal powders. The ALD design for large-scale production VIGA systems is optimized for high-throughput and cost-efficient production of high-quality metal powders. The systems are known for their reliability with highest equipment uptimes and designed for operational safety and convenient equipment operation. For example, furnaces can be equipped with double crucible doors on the melting chamber.

Large-scale VIGA system equipped with double door melting furnace chamber

 

With this configuration, each furnace door is equipped with its own vacuum induction melting station for quick crucible exchange and less process overhead time. While one crucible is in production, the second crucible can be cleaned or re-lined in stand-by position, ready to use for the next melt. With this design, equipment downtime is minimized and production flexibility is improved. The system design also allows the flexibility to use different crucible sizes that share a single gas atomization system.

Another custom design for high-throughput VIGA systems uses two tundishes arranged on a movable cart. Should the outlet nozzle of the first tundish system become clogged, the second pre-heated tundish system is moved into atomization position to continue and finish the process. The redundant tundish system increases the operational safety and minimizes potential production losses whenever the outlet nozzle requires cleaning.

VIGA2B-EIGA Dual Front End System

The VIGA2B-EIGA integrated system was specifically developed for laboratory use and R&D projects. This system is operated with either a VIGA2B melting chamber or an EIGA melting chamber, and the chamber change over requires only a few hours. All other equipment and sub-assemblies are used for both operational modes without any need for system component changes.

The two operational modes of VIGA2B-EIGA integrated system enable production of a broad spectrum of different metal powders.

Customer Benefits

  • State-of-the-art VIGA and EIGA furnaces with capacities from 5 kg up to 2500 kg per batch for production of high purity, spherical metal powders
  • Broad spectrum of customized inert gas atomizer designs to meet a wide range of market requirements based on ALD unique engineering solutions
  • High quality product, high powder yields, repeatable product properties and narrow particle size distribution by precise control of all critical process parameters
  • Energy- and cost-efficient production of a wide range of metal powders using optimized VIGA and EIGA furnace designs
  • Long-term expertise in inert gas atomizer engineering, numerous field installations and comprehensive services for equipment assembly and commissioning ensure trouble-free production ramp-up

Our clients trust ALD’s 150 years’ experience and knowledge in developing, engineering and supporting advanced furnaces designs and choose from diverse state-of-the-art VIGA and EIGA systems for production of numerous high-performance metal powders. If you require a specialized furnace concept, ALD welcomes the opportunity to engineer and build a customer-specific inert gas atomizer which meets your requirements and applications.

For more details please contact

Michael.Hohmann, Fon +49 6181 307 3309, Michael.Hohmann@ald-vt.de
Christian Lehnert, Fon + 49 6181 307 3318Christian.Lehnert@ald-vt.de
Holger Liphardt, Fon + 49 6181 307 3306, Holger.Liphardt@ald-vt.de