| Investment or lost wax casting is a versatile but | | | | Lost foam casting or (LFC) is a type of metal casting |
| ancient process, it is used to manufacture a huge | | | | process that uses expendable foam patterns to |
| variety of parts ranging from turbocharger wheels to | | | | produce castings. Lost foam casting utilises a foam |
| golf club heads, from electronic boxes to hip | | | | pattern which remains in the mould during metal |
| replacement implants. | | | | pouring. The foam pattern is replaced by molten metal, |
| The industry, though heavily dependent on aerospace | | | | producing the casting. |
| and defence outlets, has expanded to meet a | | | | The use of foam patterns for metal casting was |
| widening range of applications. Modern investment | | | | patented by H.F. Shroyer during then year of 1958. In |
| casting has its roots in the heavy demands of the | | | | Shroyer's patent, a pattern was machined from a |
| Second World War, but it was the adoption of jet | | | | block of expanded polystyrene (EPS) and supported |
| propulsion for military and then for civilian aircraft that | | | | by bonded sand during pouring. This process is known |
| stimulated the transformation of the ancient craft of | | | | as the full mould process. |
| lost wax casting into one of the foremost techniques | | | | With the full mould process, the pattern is usually |
| of modern industry. | | | | machined from an EPS block and is used to make |
| Investment casting expanded greatly worldwide during | | | | large, one-of-a kind castings. The full mould process |
| the 1980s, in particular to meet growing demands for | | | | was originally known as the lost foam process. |
| aircraft engine and airframe parts. Today, investment | | | | However, current patents have required that the |
| casting is a leading part of the foundry industry, with | | | | generic term for the process is known as full mould. |
| investment castings now accounting for 15% by value | | | | It wasn't until 1964 when, M.C. Fleming's used unbonded |
| of all cast metal production in the UK. | | | | dry silica sand with the process. This is known today |
| It really is the modernisation of an ancient art. | | | | as lost foam casting (LFC). With LFC, the foam |
| Lost wax casting has been used for at least six | | | | pattern is moulded from polystyrene beads. LFC is |
| millennia for sculpture and jewellery. About one | | | | differentiated from the full mould method by the use of |
| hundred years ago, dental inlays and, later, surgical | | | | unbonded sand (LFC) as opposed to bonded sand (full |
| implants were made using the technique. World War | | | | mould process). |
| two accelerated the demand for new technology and | | | | Foam casting techniques have been referred to by a |
| then with the introduction of gas turbines for military | | | | variety of generic and proprietary names. Among |
| aircraft propulsion transformed the ancient craft into a | | | | these are lost foam, evaporative pattern casting, |
| modern metal-forming process. | | | | evaporative foam casting, full mould, Styrocast, |
| Turbine blades and vanes had to withstand higher | | | | Foamcast, Styrocast, and foam vaporization casting. |
| temperatures as designers increased engine efficiency | | | | All these terms have led to much confusion about the |
| by raising inlet gas temperatures. Modern technology | | | | process for the design engineer, casting user and |
| has certainly benefited from a very old and ancient | | | | casting producer. The lost foam process has even |
| metal casting process. The lost wax casting technique | | | | been adopted by people who practice the art of home |
| eventually led to the development of the process | | | | hobby foundry work, it provides a relatively simple & |
| known as Lost Foam Casting. What is Lost Foam | | | | inexpensive method of producing metal castings in the |
| Casting? | | | | backyard foundry. |