- Among past successes is the PQ2 Diagram, which matches high-pressure die-casting dies to die-casting machine performance. It is now considered a fundamental die design tool. As well, the design and use of tapered tangential runners for aluminium and zinc die-casting helps die-casters worldwide to produce high-quality, cost-effective pressure die-castings.
- CASTFLOW, a software package for runner design, and CASTHERM for thermal design of dies came out of the PQ2 Diagram and were commercialised by CASTEC (Australia) Pty Ltd.
The President of the Australian Die Casting Association, Graham Wilson, says Australian companies have benefited from CSIRO collaborative research which has assisted them in finding export markets. He also emphasises that what has occurred is the smooth application of high technology to the manufacturing industry, providing strong employment opportunities and tool making spin-offs. This implies that in producing technologically difficult components for niche markets, Australian die-casters have shown their strengths, using their in-house expertise to solve problems for manufacturers, rather than in designing simpler mass market products. This expertise has been recognised in local-global partnerships to manufacture components predominantly for the automotive industry, Wilson Nissan Casting Australia Pty Ltd, declares it has had a highly productive involvement in collaboration with CSIRO and expects this to continue.
The improvements so far include:
- Reduction in metal loss of more than 1.5%.
- Soldering downtime reduced by as much as 3%.
New projects have developed from the interchange of ideas across the membership of the Cooperative Research Centre for Cast Metals Manufacturing (CAST), which is supported by Australian governments, CSIRO, several universities, smelting companies, manufacturers and die-casting companies. A unique combination of participants, indeed. Laser cladding of die surfaces: This technique looks at the controlled generation of highly [thermally] stable alloys on the die surfaces, metal powder being carried to the point of melting through an advanced microprocessor controlled carrier gas system. A patent pending on a soldering-resistant material for laser cladding. Nissan Casting Australia, claims an early outcome of the collaboration was a die for a water-cooled, low-pressure cylinder head, which was made available to all car manufacturers taking part in the project.
Other successful projects included:
- a reduction in the incidence of soldering,
- an investigation into die-casting machine parameters and
- the development of a machine monitoring system using sensors.
A shot monitoring project incorporating linear transducers gave very accurate results, and also allowed for the clear identification of what was happening in the die-casting tool itself. These findings are very crucial in overall understanding of the operational problems in PDC. Ongoing research aims to improve productivity and reduce costs. CSIRO sees lucrative chances in expanding services to industry beyond national borders, with die-casting teams in Melbourne, looking towards filling a gap in agreed process- and die-design guidelines for gravity die-casting technology and low-pressure die-casting all over the world. Inconsistency, reduced reliability and reduced profit in the final products are often the result of dies designed using a trial-and-error method, they claim, and rightfully so indeed. They are also making extensive use of computer simulation for immediate needs in die design, while also addressing the lack of guidelines. This involves 3D simulation of metal flow during die-filling, heat flow and solidification, and, in some cases, residual stress which may cause distortion of casting and dies.
The CSIRO research team uses major software packages such as MAGMAsoft, ProCAST, FLOW-3D, as well as software it has developed. The team also holds extensive databases of thermo-physical properties, especially heat transfer data for a range of materials, in order to model fluid flow and heat flow processes. Pilot plant machines for low- and high-pressure, squeeze and gravity tilt die-casting are available for die trials and experimentation in aluminium and magnesium alloys. Australia is a growing exporter of aluminium castings, to the extent that automotive die-casting exports now exceed the domestic industry consumption. Cylinder heads are exported to Toyota, Mitsubishi and Nissan in Japan, and to Daewoo in Korea. Engine components are sent to both Japan and Korea, transmission cases are exported to the European and Japanese markets, and wheels are exported to the USA as well as being available on the global market. CSIRO has designed tooling for a number of aluminium automotive gravity die-castings. Examples are an inlet manifold for a four-cylinder car engine, with a complex and heavy sand core producing thin walls and an excellent surface finish. CSIROs research facilities are extensive, including the following:
o A 250 t Toshiba cold chamber machine,
o An IDRA 125 t magnesium hot chamber machine,
o A Rimatic low-pressure die-casting machine,
o A Rauch magnesium melter and dosing furnace,
o A UBE squeeze casting machine,
o A battery of gravity tilt casting machines,
o A horizontal continuous direct chill caster and
o A twin roll caster, both for magnesium casting. Associated support facilities cover the following:
o several aluminium and magnesium melting furnaces,
o mechanical testing equipment,
o a cabinet X-ray fluoroscope,
o a fluidised bed heat treatment furnace,
o an infra-red thermal imaging camera, spectrometers and electron microscopy. All together a formidable array of developmental arsenal indeed.
Conclusion
From the discussion above, it is obvious that a lot of applied research has been carried out in many places for fine-tuning some of the innovations in pressure die casting process and its variants. Many useful ideas have already been translated into actual and tangible benefits as shown above. It is therefore the authors sincerest wish to assist any pressure die casting industry in India where new ideas and technologies can find a fertile ground. The technological gap between us and the more technologically-advanced nations is narrowing down almost on a daily basis though of course there happen to be blind spots where the gap is as large as ever. It needs a concerted effort on part of the laboratories, academia and the industry. A beginning has to be made somewhere and PDC as a lively segment of our industry today, could provide that much-required springboard to take the first plunge
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