Melting critical superalloys under high vacuum conditions demands tight controls and strict adherence to approved manufacturing procedures. Everything, from the selection of raw materials to vacuum pressures, vacuum leak rates, melting and refining practices and pouring techniques, is closely monitored against standard operating procedures and internal specifications to ensure quality is never compromised.
Rigid control of highly reactive elements, distillation of volatile impurities and maintenance of melt quality can only be achieved by the strict application of process controls developed through many years’ experience in producing complex vacuum melted superalloys.
The conventional pouring technique used to transfer molten alloy from the furnace and into the moulds has been developed and fine tuned over the years to maximise alloy quality and cleanness and at the same time minimise centreline shrinkage. Purpose designed refractory tundishes and filter technology are an integral part of the production process.
Ross & Catherall’s and CAPI’s air melt departments operate numerous air induction melting furnaces allowing them to offer customers a wide range of yield weights from 500 to 2,300 kg (1,102 – 5,070 lb). A comprehensive range of iron, nickel and cobalt based alloys can be produced either to individual customer requirements or to internationally accepted specifications as required.
The production of airmelted superalloys involves a fully automatic metal mould casting machine delivering moulds to two pouring stations. By utilising two stations, overall pouring times are reduced to a minimum ensuring close control of chemistry throughout the heat. The transfer of molten alloy from the furnace to the moulds is achieved by the use of teapot ladles.
The coated metal moulds ensure a high standard of barstock surface finish. A typical open bar poured weight is 3 to 5 kg (6.6 – 11 lb) but varying bar weights from approximately 2.5 up to 6 kg (5.5 – 13.2 lb) can be poured to suit the customer’s individual requirements.
All airmelted ingots are shotblasted, individually inspected and marked before packing and dispatch.
open bar poured weight
open bar poured weight
Doncasters is one of the largest and most respected cast superalloy manufacturers.
Through its two core facilities, Doncasters offers advanced alloys that are used across a wide range of performance critical applications as diverse as turbine blades and vanes and other components for aero engines and land based gas turbines, hot-end turbocharger wheels, medical prosthesis, and other special components requiring high metallurgical integrity.
Doncasters Superalloys production facilities excel at vacuum induction melting, air induction melting and vacuum degassing. All use the highest quality materials and guarantee the highest level of technical control, ensuring a consistent product with a repeatable tightly controlled chemistry.
In addition, the Doncasters Group has a number of supporting facilities capable of manufacturing components and systems from these advanced materials.