ALD Vacuum Technologies

With our EBuild®850, ALD has developed a completely new system for the electron beam powder bed fusion (E-PBF) process on an industrial scale. It is the first system on the market that is suitable for both large-scale additive manufacturing and high-volume production. High productivity, robustness and material quality enable the step towards industrial additive manufacturing. The world's largest build volume and highest beam power currently available in E-PBF significantly expand the possibilities for new products and materials. The benefits achieved lead to both cost reduction and a lower carbon footprint in production and in the product life cycle.

ALD Vacuum Technologies designs, engineers, and produces advanced vacuum metallurgy and heat treatment furnace systems involving many different technologies of interest to the AM and PM markets, including master melt electrode and barstick production of certified material. Close cooperation with well-known manufacturers and OEMs have strengthened ALD’s capabilities as a supplier of key technologies to demanding aviation, power generation, environmental, photovoltaic and automotive markets.

ALD invented and patented the EIGA in the 1980s to atomize spherical titanium alloys for aerospace and electronics PM applications.  We have now reinvented the EIGA Premium for the finer useable fractions demanded of AM and MIM (metal injection molding).

For a common titanium alloy, the EIGA Premium’s d50 reduction from 65 to 35 microns increases the useable fraction in the SLM and in the MIM range substantially.  With the EIGA Premium reducing specific gas consumption 50% to 75%, cost of conversion drops by half, and EIGA Premium now also becomes a real alternative to VIGA for super-clean requirements of Ni-, Cr-, Fe- based special alloy powders. Generally, all metals and alloys with melting points up to approximately 3000 °C can be converted into powders with the EIGA process. Electrodes with up to 150 mm diameter and up to 1500 mm length can be used as feedstock.

EIGA systems are the most versatile method for converting a wide variety of metals and special alloy electrodes into metal powders. The ceramic-free material processing and the outstanding process simplicity and robustness are the inherent advantages of the EIGA process. Powders produced by the EIGA process can be used in numerous applications and typically have the following characteristics:

    Spherical shape

    Good rheological flow characteristics

    Particle sizes ranging from 40 µm ≤ d50 ≤ 100 µm

    High purity

    High flow ability

    Low O, N and N concentrations

    Rapidly solidified and homogeneous microstructure

The EIGA system design is based on a vertically-oriented, rotating electrode that is continuously melted at one end in an inert gas atmosphere, without a ceramic crucible, using controlled motion into a specially designed, conical induction coil.  The design of the induction coil and the frequency of the generator are optimized to achieve the necessary heat, causing the melt to drop from one end of the electrode. With proper controls, a continuous stream of molten material is atomized with an inert gas nozzle using a high-velocity gas stream. The micro-droplets spray solidifies while traveling down the atomization tower and forms spherically shaped fine powders which are collected in a vacuum-tight powder container.

As part of AMG Advanced Metallurgical Group N.V., Netherlands, ALD employs approximately 900 people in 10 countries.  AMG is a global critical materials company at the forefront of CO₂ reduction trends and emerging technologies, producing highly engineered specialty metals and mineral products.

The new SyncroTherm® – unit from ALD Vacuum Technologies provides for the first time the complete and total integration of heat treatment into the manufacturing work center. With this unit, the case hardening process is fully synchronized with the cycle of soft-machining, therefore allowing a continuous “One-Piece Flow”.

Technology at a glance

The case hardening process is drastically accelerated in the SyncroTherm® -unit, so that the process matches the cycle-time of soft-machining. Instead of big batches with multiple layers, the components are treated in one layer only. These so called “2D-batches” guarantee a rapid and very homogenous heat treatment for all heat treatment steps. This homogenous treatment guarantees optimum reproducibility of the heat treat quality.

The SyncroTherm® plant consists of a pressure-tight chamber in the front which serves primarily as quench chamber as well as loading chamber. The treatment chamber located behind this chamber comprises a cold loading area with telescopic loader and up to six hot zones which are arranged one upon the other. Each hot zone may hold one workpiece carrier. The treatment chamber always remains under vacuum and is separated from the quench/loading chamber by a pressure-tight door.

The One-Piece-Flow-Principle

According to the one-piece-flow principle, the heat treatment of large batches is converted to treatment of single components. The parts are charged in one layer on one workpiece carrier. The flat-panel radiators installed in top and bottom radiate the heat directly onto each part, heating the “2D-charges” rapidly and homogeneously. The micro-alloyed steel parts are carburized at high temperatures above 1,000 °C without undesired grain growth. Furthermore, the single layer charge provides the possibility to control high pressure gas quenching which is customized for various parts, shapes and dimensions.

Plant technology

The SyncroTherm® plant consists of a pressure-tight chamber in the front which serves primarily as quench chamber as well as loading chamber. The treatment chamber located behind this chamber comprises a cold loading area with telescopic loader and up to six hot zones which are arranged one upon the other. Each
hot zone may hold one workpiece carrier. The treatment chamber always remains under vacuum and is separated from the quench/loading chamber by a pressure-tight door.

The process

The external handling system places single parts on the workpiece carrier and transports it through the front opening in the quench chamber, which now serves as a loading chamber. The chamber is evacuated in order to remove unwanted oxygen. The telescopic loader, integrated in the treatment chamber, proceeds
to place the workpiece carrier into a vacant hot zone. In the hot zone the strong radiant heat rapidly and homogeneously heats the parts to
treatment temperature, followed by carburization and diffusion. Temperature and process gas supply are controlled independently in each hot zone.

After carburizationing, the telescopic loader returns the workpiece carrier with the carburized parts to the quench chamber. The chamber is flooded with quench gas (nitrogen) to a maximum pressure of 6 bar. The installed gas circulator directs the gas flow over the parts for rapid and homogeneous quenching. Subsequently, the chamber is ventilated and the workpiece carrier containing the casehardened parts is transported out of the chamber. The handling system singularizes the parts and transports them to the respective stations for further processing.