Revolutionizing aluminum casting
The launch of ROBOCAST V for higher efficiency and quality.
A techncal articel by Edmundo Oliveira, MSc, R&D, Fill Gesellschaft m.b.H.
The conventional technique of producing parts made of metal and metal alloys by casting molten metal into molds is one of the most widely used methods in the field of manufacturing. As the demands on the quality of castings become ever more stringent in various market segments, both the materials and the processes have to be constantly optimized.
The manual casting method using casting ladles is still a key process in the foundry industry even today. Manual casting is particularly important to companies with a broad product portfolio and limited production quantities.
But manual casting also has disadvantages: Apart from the fluctuating quality of the parts, the long cycle times are also a major drawback of the manual casting process. The quality depends directly on the skills of the respective personnel, who are also exposed to high emissions and safety risks when working with the molten metal. A repeatable high product quality cannot be consistently guaranteed due to the harsh foundry conditions.
Development of the ROBOCAST V
In order to overcome these disadvantages, Fill has developed the ROBOCAST V – a groundbreaking innovation in non-ferrous metal casting. The vacuum dosing unit creates a system in which the molten metal is taken from the holding furnace and poured into the molds turbulence-free – in a controlled, precise and repeatable manner. During the processing of aluminum alloys in the ROBOCAST V, a controlled inert gas atmosphere surrounds the molten alloy to prevent oxide formation.
The process of drawing the melt from the holding furnace is performed by a very precisely controlled pressurized atmosphere within the ROBOCAST V unit. These dynamics are determined by the change in cross-sectional area along the flow path into the ROBOCAST V vessel. By regulating the vacuum, the flow of the molten aluminum is carefully controlled, ensuring a turbulence-free, oxide-free surface of the molten aluminum. The molten aluminum is then safely enclosed in a vessel that ensures minimum temperature losses during transport to the mold.
Fig.1: Dosing via the molten surface of the furnace
„We followed the first castings of the ROBOCAST V in our furane mold on the test configuration with great excitement. I am fascinated by the low-turbulence mold filling and the reproducibility of the casting result.“
//Tatjana Schüle, Management Consultant, Schüle Metal Foundry
Increased casting accuracy and repeatability
The innovation of the ROBOCAST V lies in its dosing system. With its pouring tube, the system enables the melt to be fed into the mold with pinpoint accuracy, e.g. into the lower part of the sprue in front of the gating system or directly to the base of the sand mold. This eliminates the need to pour the molten aluminum from above, which often leads to strong turbulence resulting in poor casting quality.
The speed of the metered flow is controlled and can be adapted to the complexity of the mold for the part to be cast. This control of the flow speed offers a number of benefits, such as reducing sand erosion on cores and mold walls, particularly in regions where chills are located.
Fig. 2: Difference between manual casting and ROBOCAST V dosing method
Evolution in energy efficiency and operator comfort
Apart from the benefits described above, reducing the energy consumption of the holding furnace is another major development step towards an efficient foundry. Thanks to the geometry of the pouring tube of the ROBOCAST V, a much smaller opening in the cover of the holding furnace is possible, resulting in considerable energy saving potentials. In conventional casting processes, casters are forced to overheat the molten metal to compensate the losses caused by opening the furnace cover and transporting the molten metal. In this scenario, the ROBOCAST V has proved to be a key factor for improvement. By eliminating the overheating, energy consumption is reduced by up to 42%, which significantly reduces the energy requirements for the furnace.
The smaller opening in the furnace cover ensures a more pleasant working environment and increases both safety and comfort for the foundry personnel.
The launch of the ROBOCAST V represents a turning point in the foundry industry, pushing back conventional process boundaries and bringing with it process precision, energy efficiency and high casting quality.
"In our view, the development of the ROBOCAST V technology promises a real technological leap forward in the mold filling for castings. We are therefore delighted to be able to test a process analysis for the implementation of the process for customer castings together with Fill as part of the AI5Production project funded by TestBeforeInvest. We are looking forward to the further cooperation.”
//Joshua Bissels, Wirt.-Ing. M.Sc.RWTH, Head of Innovation and Process Development, Pinter Guss GmbH
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