Contact

Buenting, Aiko Dr.-Ing.
Head of permanent mold castings
Chair for comprehensive Foundry Science and Foundry Institute

Tel.: +49 (0) 241 80 - 98916
a.buenting@gi.rwth-aachen.de

Light Metal Casting

New materials and processes are a key factor for the sustainability of the Foundry business due to increasing demands for improvements in terms of cast part performance and efficiency. The research group “Innovative Casting Processes” at the Foundry Institute addresses these challenges by developing and optimizing casting processes. Fundamental developments in the field of casting materials, dies and measurement technologies shall be used in order to manufacture highly complex components in a precise manner. Another focus is the development of hybrid technologies. These combine the advantages of cast parts, stamped parts, fibers and plastics in order to increase the performance of future Castings.

High Pressure Die-Casting

Research in the field of high pressure die-casting at the Foundry Institute in Aachen is carried out on two machines both based on the horizontal cold-chamber technologie. One is a Bühler H-630 SC and the other one is a Frech DAK 450 Vacural machine.

The automated Bühler H-630 SC (Shot Control) cold-chamber pressure die-casting unit has a maximum locking force of approximately 700t. The machine’s real-time controller permits the parameters of the pouring curve to be precisely followed. To do this, the speed, the back-pressure of the metal on the injection plunger and the displacement of the casting plunger are monitored. The equipment possesses a state-of-the-art ladle dosing unit and a robotic spraying unit from the company Wollin equipped with a highly flexible matrix-sprayhead. A Fondarex vacuum system facilitates vacuum supported high pressure casting. The Frech DAK 450 Vacural has a maximum locking force of 500t. With its various equipment options the machine shows a highly modular setup and can be used for various experimental setups. Three furnaces build by Meltec can be used with this machine, one build for the use of aluminium, one for magnesium and a third furnaces for the Vacural process. In addition to that a Arburg unit has been added in order to be able to manufacture both thermos- and duroplast plastics. A variothermal temperature control unit build by Single was added in order to support the manufacturing of plastic components.

Current research activities in the field of high pressure die-casting concentrate on Al and Mg alloys, composite materials and composite components, as well as on the thermal control of high pressure die-casting dies.

Tool designs for High Pressure Die-Casting

In this area, priority is given to optimising the geometry of individual components with the aid of numerical optimising techniques. Apart from the gate geometry, work is also to be carried out on the temperature control. Moreover with regard to this, new approaches for manufacturing tool inserts are to be developed and tested. Here, additive manufacturing processes are to play an essential role.

Precision Increase in Permanent Mould Casting Processes

By employing a combination of established manufacturing processes, construction principles and materials, new perspectives are provided for implementing maximum weight savings and performance increases as well as for improving the efficiency of production processes. Hybrid components are manufactured by recasting structured steel or aluminium sheet inserts using Al or Mg light metal melts. Geometric, detachable and non-detachable bonds are ensured by perforations in the inserts or by micro scale types of connections such as functional coatings and surface topologies. In the Cluster of Excellence „Integrative Production Technology for High-Wage Countries“, pressure die-casting of metal is combined with polymer injection moulding in a two-stage process. Using a single moulding tool, aluminium components are initially produced onto which a polymer component is injection moulded and adhesively bonded during a second process step.

Hybrid High Pressure Die-Casting

By employing a combination of established manufacturing processes, construction principles and materials, new perspectives are provided for implementing maximum weight savings and performance increases as well as for improving the efficiency of production processes. Hybrid components are manufactured by recasting structured steel or aluminium sheet inserts using Al or Mg light metal melts. Geometric, detachable and non-detachable bonds are ensured by perforations in the inserts or by micro scale types of connections such as functional coatings and surface topologies. In the Cluster of Excellence „Integrative Production Technology for High-Wage Countries“, pressure die-casting of metal is combined with polymer injection moulding in a two-stage process. Using a single moulding tool, aluminium components are initially produced onto which a polymer component is injection moulded and adhesively bonded during a second process step.

Gravity and Tilt Die-Casting

The gas-heated tilting, die-casting machine MBS Senator KMC 4 is suitable for both gravity and tilt die-casting. The maximum mould weight is 1800kg for a clamping surface of 1000mm x 1200mm. The equipment can be pivoted through 90° for tilt casting whereby the tilt angle and speed can be programmed by the user via nine control points. It is possible to employ sand cores and core slides. Currently, alloys are being developed for the die-casting process. In addition, component-specific investigations can be performed with respect to the casting process-window (poring curve, heat balance, influence of coatings on the microstructure, etc.).