Foundry Practice is Foseco’s technical journal and is provided free of charge to the foundry industry.
First published in 1932, Foundry Practice aims to keep customers informed of the latest developments in our proprietary products and services and encourage the implementation of best practice.
Articles highlight the latest innovations and show case studies of how we have worked with customers to improve processes, productivity and ultimately profitability.
Controlling the structure of aluminium alloys before casting with the thermal analysis equipment THERMATEST* 5000 NG III.
Specifically for aluminium alloys, thermal analysis enables foundrymen to predict the grain refinement and type of eutectic structure before casting aluminium silicon alloys. THERMATEST 5000 NG III is a well–proven thermal analysis device which is quick and easy to use by foundry personnel. It gives quantitative outputs which ensure a consistent level of casting quality. These values can be used to set the optimum addition rates for all grain refining and modification additives and thus to avoid costly scrap due to shrinkage, leakage, porosity and hot tear.
Insulating lids offer further improvements to ladle temperature control.
When liquid metal, particularly steel, is tapped from a furnace into a ladle, allowance must be made for the heat that will be lost in the transfer process from furnace to mould. To compensate for this heat loss the metal is “superheated” in an attempt to ensure the metal arrives at the mould at the correct temperature for casting. With today’s energy prices this can be an extremely expensive process and contributes significantly to the production cost of the castings manufactured.
There are a number of ways of reducing the potential for heat loss, including extensive preheating of ladles and the use of insulating linings. Even with these precautions it is still possible to lose a considerable amount of heat from the surface of the metal.
The use of an insulating lid together with an insulating ladle lining can have a dramatic effect on reducing the rate of heat loss.
Enhancing filtration knowledge to improve foundry performance.
The ability of ceramic foam filters to reduce ductile iron inclusions is now well proven and documented, however, in order to improve upon the current situation a better understanding of the mechanisms of filtration will enable further advances and improved foundry performance. This paper defines and quantifies the forces involved in filtration based upon physical water modelling and mathematical simulations leading to a fuller understanding of the mechanisms of the process. The experimental set up is described and the mathematical modelling explained. The results of the paper indicate clearly that mathematical modelling can be used to reliably predict pressure dynamic variations when used against water modelling. It also justifies the design and conducting of hot metal experiments to confirm the findings. This can only lead to improvements in filtration efficiency in the future to the ultimate benefit of the end user.
Effective grain refinement improves the mechanical properties of all cast metals, however in magnesium the common techniques for reducing grain size were either not very practical or were environmentally unacceptable. NUCLEANT* 5000 is an effective and environmentally friendly product that can reduce the grain size of cast magnesium parts thus increasing mechanical properties.
