Production of components by hot isostatic pressing of nickel-base superalloy powders

Turbine disks for gas turbine engines are made from nickel-base superalloys but can be fabricated by several processing methods. The choice of a specific processing route depends on a variety of interrelated factors which include design property requirements, materials selected, and processing costs. It is shown that disk fabrication by direct hot isostatic consolidation of nickel-base superalloy powders, is the most cost-effective method of production; however, such a manufacturing route must yield a product compatible with the property requirements of the component. Some of the metallurgicalfactors that influence such properties in as-hot isostatically pressed (HIP) material are examined. It is shown that by control of the HIP condition, manipulation of composition and heat treatment can be used to control properties. Discussion centres on the balance between strength and stress rupture properties, and resultsfor low-carbon Astroloy and a modified IN 100 alloy, identified in a recent alloy development programme, are used to illustrate the property balances that can be achieved in HIP materials.