EIGA systems

Electrode Induction Melting Inert Gas Atomization systems for melting and atomizing electrodes up to 150 mm in diameter and 1000 mm in length

ALD Vacuum Technologies GmbH is the market and technology leader for vacuum inert gas atomization systems for the production of high-quality metal powders. In addition, ALD has extensive experience in combining different melting technologies with inert gas atomizers for special material requirements. The application-specific combination of melting and atomization technologies enables the production of many different high-purity metal powders, such as Ni superalloy, precious metal or high-melting and reactive metal alloy powders. For feed weights between 5 and 2500 kg, our customers can mainly choose between two atomization types, namely EIGA and VIGA. Customized EIGA and VIGA configurations are available to meet specific customer requirements.

The electrode induction melting process with inert gas atomization was developed and patented by ALD as an alternative, ceramic-free melting and atomization process for the production of high-purity, reactive and refractory metal and precious metal powders. Today, the EIGA process is one of the leading processes for producing high-quality powders from titanium, zirconium, niobium and tantalum alloys.

The EIGA concept is based on a vertically suspended, rotating electrode, which is continuously melted at the lower end in a specially designed conical induction coil under vacuum or in an inert gas atmosphere by a controlled movement.

The design of the induction coil and the generator frequency are optimized for melting the electrode and dripping the melt from one end of the electrode. With suitable control, a continuous melt stream is generated which flows directly into the center of an inert gas nozzle. The resulting melt stream is atomized in the nozzle using high pressure inert gas and a spray of micro-droplets is generated. On its way through the atomization tower, the fine mist of micro-droplets solidifies and forms a spherically shaped, fine-grained powder, which is collected in a vacuum-tight container.

Characteristics of the powder

Powders produced in an EIGA system from ALD have the following typical properties:

• Spherical powder morphology
• Good flow properties
• Particle sizes between 40 µm ≤ d₅₀ ≤ 100 µm
• High purity
• Low concentration O, N and H
• Rapidly solidified, homogeneous microstructure

Applications for materials and metal powders

EIGA-Anlagen sind besonders vielseitig in der Herstellung von Metallpulvern aus Elektroden aus unterschiedlichen Metallen und Speziallegierungen. Mit dem EIGA-Verfahren lassen sich generell alle Metalle und Legierungen mit einem Schmelzpunkt bis maximal 2500 °C zu Pulver verarbeiten. Als Rohmaterial eignen sich Elektroden mit einem Durchmesser von bis zu 150 mm und einer Länge von 1000 mm. Das EIGA-Verfahren hat den besonderen Vorteil der keramikfreien Materialverarbeitung und einer bemerkenswerten Einfachheit und Robustheit des Prozess. Die damit hergestellten Pulver eignen sich für zahlreiche Anwendungen. In EIGA-Anlagen werden vor allem die folgenden Materialien für folgende Anwendungsbereiche hergestellt:

EIGA systems

Electrode Induction Melting Inert Gas Atomization systems for melting and atomizing electrodes up to 150 mm in diameter and 1000 mm in length

ALD Vacuum Technologies GmbH is the market and technology leader for vacuum inert gas atomization systems for the production of high-quality metal powders. In addition, ALD has extensive experience in combining different melting technologies with inert gas atomizers for special material requirements. The application-specific combination of melting and atomization technologies enables the production of many different high-purity metal powders, such as Ni superalloy, precious metal or high-melting and reactive metal alloy powders. For feed weights between 5 and 2500 kg, our customers can mainly choose between two atomization types, namely EIGA and VIGA. Customized EIGA and VIGA configurations are available to meet specific customer requirements.

The electrode induction melting process with inert gas atomization was developed and patented by ALD as an alternative, ceramic-free melting and atomization process for the production of high-purity, reactive and refractory metal and precious metal powders. Today, the EIGA process is one of the leading processes for producing high-quality powders from titanium, zirconium, niobium and tantalum alloys.

The EIGA concept is based on a vertically suspended, rotating electrode, which is continuously melted at the lower end in a specially designed conical induction coil under vacuum or in an inert gas atmosphere by a controlled movement.

The design of the induction coil and the generator frequency are optimized for melting the electrode and dripping the melt from one end of the electrode. With suitable control, a continuous melt stream is generated which flows directly into the center of an inert gas nozzle. The resulting melt stream is atomized in the nozzle using high pressure inert gas and a spray of micro-droplets is generated. On its way through the atomization tower, the fine mist of micro-droplets solidifies and forms a spherically shaped, fine-grained powder, which is collected in a vacuum-tight container.

Characteristics of the powder

Powders produced in an EIGA system from ALD have the following typical properties

• Spherical powder morphology
• Good flow properties
• Particle sizes between 40 µm ≤ d₅₀ ≤ 100 µm
• High purity
• Low concentration of O, N und H
• Rapidly solidified, homogeneous microstructure

Applications for materials and metal powders

EIGA systems are particularly versatile in the production of metal powders from electrodes made of different metals and special alloys. The EIGA process can generally be used to process all metals and alloys with a melting point of up to 2500 °C into powder. Electrodes with a diameter of up to 150 mm and a length of 1000 mm are suitable as raw material. The EIGA process has the particular advantage of ceramic-free material processing and the remarkable simplicity and robustness of the process. The powders produced in this way are suitable for numerous applications. The following materials in particular are produced in EIGA systems for the following areas of application:

Target Markets

• Aerospace industry
• Energy technology
• Spray metallization
• Raw material for additive manufacturing technologies (e.g. 3D printing)
• Raw material for MIM and HIP
• Chemical and electronics industry
• Biomedical technology
• Precious metals industry
• Research and development

Integrated/combined VIGA2B-EIGA systems

The integrated VIGA2B-EIGA system was specially developed for use in laboratories and R&D projects. The system is operated with either a VIGA2B or an EIGA melting chamber, whereby the chamber can be changed in just a few hours. The other devices and assemblies are designed for both system configurations and do not need to be changed.

In its two operating modes, the integrated VIGA2B-EIGA system enables the production of a wide range of different metal powders.

Customer Benefits

• State-of-the-art VIGA and EIGA systems with capacities from 5 to 2500 kg per batch for the production of high-purity, spherical metal powders
• Robust and fault-tolerant process and short cycle times of just 15 to 60 minutes
• Numerous specially adapted inert gas atomization systems for all market requirements thanks to exclusive design solutions from ALD
• High-quality products, high powder yield, reproducible product properties and a narrow particle size distribution thanks to the precise control of all critical process parameters
• Energy-saving and economical production of many different metal powders thanks to the optimized design of the VIGA and EIGA systems
• Years of expertise in inert gas atomization technology, excellent references and numerous installations worldwide as well as a comprehensive range of services for assembly and commissioning guarantee a smooth production start-up

Our customers rely on our 150 years of experience and knowledge in the development, design and support of advanced vacuum systems and can choose from a range of state-of-the-art VIGA and EIGA systems for the production of a wide variety of high-performance metal powders. If you require a special furnace concept, ALD will design and build a customized inert gas atomizer to meet your exact requirements and applications.