A new type of foam can replace wax in lost-wax casting of aerospace components and the US Air Force Research Laboratory estimates industry's savings will be worth millions of dollars.
The high savings are expected because, according to the AFRL, traditional casting processes and designs are severely limited due to the properties of wax, with high scrap rates resulting from problems such as material distortion.
Lost-wax casting, one type of manufacturing process using wax, involves packing in sand a wax pattern of the item to be produced; this packing makes a mould, into which molten metal is poured, melting and displacing the wax.
The new foam process eliminates wax-pattern making and wax-melt cycles and is temperature stable, energy-efficient in its use and cost effective compared with wax processes. And, according to the AFRL, the foam method provides a smooth surface finish and "excellent dimensional predictability" in cast components.
The AFRL estimates a cost saving to the Lockheed Martin F-35 Joint Strike Fighter's engine programmes alone of $13 million.
The foam that will replace the wax for this and other casting processes was developed by US company Fopat Production, with a two-year US Department of Energy inventions and innovation programme grant and consecutive US Air Force small business contracts.
Source: Flight International
