Lost wax Casting / Investment Casting

Lost wax casting, or investment casting is a century’s old process of producing near to shape components which are of high integrity, good surface finish and close dimensional accuracy, which means post operations such as machining can often be reduced significantly or eradicated altogether. Investment casting is an industrial process based on and also called lost wax casting, the process is generally used for small castings, but has produced complete aircraft door frames, steel castings of up to 200 kg and aluminium castings of up to 30 kg. Lost wax casting is generally more expensive per unit than die casting or sand casting but can produce complicated shapes in practically any metal that would be difficult or impossible with other casting methods, unlike with other process, it requires little surface finishing and only minor machining. Lost wax casting has many niche applications, often being the only practical and commercially viable option of production, tooling can be complex (without necessarily adding cost to component) enabling intricate features to be formed, including internal cavities. Tooling costs for lost wax casting are also very reasonable- the tools are produced in aluminium and do not generally need to be replaced during the life of the product, and can generally be modified quite easily should there be any design modification.

Whilst generally a lower volume process, lost wax casting can be used viably to produce volumes into the hundreds of thousands/ year and automation and robotics can be employed to increase output and reduce labour content. Lost wax casting also has the additional benefit that it is compatible with most materials, from carbon steel, stainless and exotic steels through to non ferrous alloys of copper and aluminium; the use of titanium in specialist applications where high strength, low weight and excellent corrosion resistance properties are required is becoming ever more popular.