Casting technology

A steel casting technology developed by the US Department of Energy has been transferred to the US Army's Rock Island Arsenal to manufacture improved armour for vehicles.

The Office of Fossil Energy's National Energy Technology Laboratory (NETL) provided the Rock Island Arsenal with process guidelines, parameters, expertise, and patterns to set up and operate a facility for making steel castings using an NETL-developed process called loose-bonded sand, lost-foam technology. The facilities at the arsenal, in Rock Island, IL, will be used to produce the improved cast steel armour plating for Army vehicles.

The Rock Island Arsenal - the western world's largest government-owned weapons manufacturer - produces weapons and weapons components at scales from prototype to full-scale sizes. NETL scientists have designed and produced patterns and gating systems for casting armour plate in the Arsenal's foundry, and they are continuing to assist US Army researchers with process-related information and procedures.

In NETL's loose-bonded sand, lost-foam technology for casting steel, researchers make a foam pattern of a part, then dip the pattern into a water solution containing a suspended refractory. The refractory material coats the foam pattern and leaves a thin, heat-resistant layer. After sand is poured around the pattern to provide support, molten metal poured into the mould melts and vapourises the foam. The solidification of the metal and its removal from the sand gives rise to the name lost-foam casting.

Although the process appears simple, it represents a competitive technology when compared with currently used steel stamping and forging of steel parts.

NETL's technology provides a host of advantages. Lost-foam castings may be made in any shape and size and can be applied to a range of metals including steel, iron, aluminium, and nickel alloys. In addition, the technology reduces costs and development times for manufacturers.

As a result of these advantages and its ability to produce moulds of complex structures, more manufacturers are beginning to apply the lost-foam casting method to meet their specific product needs.