Serck Aviation is hot stuff when it comes to working at speed. The UK firm comes to Farnborough to show the flightworthy heat exchangers for the Pratt & Whitney PW6000 engine, produced using rapid prototyping techniques. So successful was this project that the company is now able to produce heat exchangers from CAD 3D models in 18 weeks. To develop the capability, Serck Aviation worked with the Manufacturing Engineering Centre at Cardiff University and Tritech Precision Products. The rapid prototyping technique used is a layer additive process, known as selective laser sintering.
Using a 3D CAD model a series of thin slices, typically from 0.05 to 0.3 mm thick, is built up progressively using a laser to produce a sacrificial casting pattern from sintered metal powder. Heated to just below sinter temperature under inert gas, the powder bed works as a form-fitting supporting structure as successive layers are built up.
Dedicated software automatically controls the laser path round the perimeter of the slice. This raises the temperature of the exposed area to cause it to sinter a line of powder. The part is then lowered and the process repeated until the solid form of the component is built up which is a replica of the original CAD model.
Casting is then carried out using a sacrificial casting process, followed by machining in the normal way.
Source: Flight Daily News