The two new technologies – a dynamic gating system and the ‘ATM runner system’ – produce high-integrity castings with fine-grained microstructure and low porosity by improving the feed of molten metal into the casting. Both systems are suitable for use with aluminium and magnesium alloys.
“This is accomplished by influencing the flow behaviour of the molten metal, the fill pattern of the die, and subsequent solidification,” says the leader of CSIRO’s research team of metallurgists and casting engineers, Dr Rob O’Donnell.
“Our researchers realised that by changing the way in which molten metal is delivered to the die we could take advantage of the high pressure inherent in the process to make castings with finer microstructure and lower porosity,” Dr O’Donnell says.
The researchers achieved higher quality castings by changing the architecture of the runners (the passages along which molten metal flows into the die) and the gate (the narrow opening to the die cavity).
“Our improved melt delivery systems are cost-effective, can be used with existing casting machines, and can significantly reduce the mass of the metal runner, wasting less metal.
“They represent new ‘green’ die casting technologies, which are low-energy and highly effective.”
Gases captured during the passage of the molten metal into the die cavity cause porosity, which together with voids created during solidification, reduces the quality of the casting.
Die castings with low porosity are stronger and can be successfully heat treated post-casting to improve their mechanical properties.
The dynamic gating system (DGS) incorporates a gate capable of changing its size in response to the pressure of the melt during filling.“Our improved melt delivery systems are cost-effective, can be used with existing casting machines, and can significantly reduce the mass of the metal runner, wasting less metal”
Dr Rob O'Donnell, CSIROX-ray analysis of test castings showed a significant improvement in density in both thicker and thinner areas of the casting, when the dynamic gate was used.
A paper describing the dynamic gating system received the best paper award at the North American Die Casting Association (NADCA) CastExpo10 congress, held in March in Orlando, Florida.
A reviewer of the paper commended the CSIRO researchers for producing a technology with “real-world” relevance to high pressure die casting, saying “This is a technology that has significant promise in the future of our industry”.
ATM technology uses a revolutionary melt delivery system for the high pressure die casting (HPDC) process, which is cheaper to operate than conventional HPDC.
The ATM casting technology has been proven by a number of companies in commercial production, and its effectiveness in reducing both shot weight and reject rates has been demonstrated.
“ATM conditions the melt prior to filling the cavity so that the melt enters the die in a less viscous, ‘runnier’ state,” Dr O’Donnell said.
“As a result, melt flow is improved and separate melt fronts fuse together better when they meet within the casting.”
The outcome is a casting with a more uniform distribution of nucleation sites, a refined, homogenous microstructure, and exceptionally low porosity.
CSIRO seeks commercial partners interested in licensing either the dynamic gating system or the ATM melt delivery system.
National Research Flagships
CSIRO initiated the National Research Flagships to provide science-based solutions in response to Australia’s major research challenges and opportunities. The nine Flagships form multidisciplinary teams with industry and the research community to deliver impact and benefits for Australia.
Nola Wilkinson | EurekAlert!
Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT
A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
27.06.2017 | Power and Electrical Engineering
27.06.2017 | Information Technology
27.06.2017 | Physics and Astronomy