OXIGEN will address the limitations given above for existing ODS alloys, focussed on the manufacturing of gas and steam turbine engine components for turbine generators. To achieve this, OXIGEN proposes to undertake development in four areas; (1) Development and production of powder materials, (2) Development of flexible and efficient powder-based additive manufacturing (AM) routes, (3) Intelligent component design and (4) Embedded sensing for in-service monitoring.

(1) Development and Production of Powder ODS Materials

OXIGEN will establish and extend the current state of knowledge regarding the microstructural control, modification and evolution and production of ODS, nickel superalloys and intermetallics (titanium aluminides) by:

Defining a materials performance baseline using existing materials  to assess performance increases achievable using ODS material.

Modelling using existing thermodynamic in order to predict phase formations for purpose of customisation of alloy composition for improved performance.

  • Development and screening of ODS alloys to take forward for component manufacture and/or surface coating for use in high temperature (>1,000°C) power generation
  • Tailor powder material production suitable for additive manufacture.

(2) Manufacturing Routes for Component Manufacture

Additive manufacturing (AM) techniques have been identified as a potentially attractive option for the manufacture and cladding/lining of high temperature performance components used in power generation. In particular, selective laser melting (SLM) and laser metal deposition (LMD) are both powder-based, layer by layer, AM methods which can directly build 3D structures or surface coat onto unlimited size substrates. The potential of processing the alloys proposed in OXIGEN using AM is derived from a number of factors:

Complex geometries and localised addition of sub-components are difficult, or impossible to obtain, using casting and traditional powder consolidation techniques.

  • Construction of components in layers allows for complex internal channels and the integration and embedment of sensors for component monitoring.
  • High solidification rates (4x103Ks-1 or even higher) are possible with laser AM processing which is beneficial for ODS alloys, allowing dispersions of fine oxide particles (providing high temperature strengthening) to be retained during processing.
  • AM processing allows altering of material properties during production which offers very significant benefits to conventional casting processes, such as reinforcement of joint regions.
    Resource efficient manufacture: Direct from CAD-to-Part manufacture, with nearly 100% material usage offers reduced manufacturing costs and lead time due to near net shape manufacture, where feedstock material cost is a significant factor.
  • In addition, a comparison against traditional sintering and HIPing processes (utilising the powder ODS alloy developed in activity (1)) will be undertaken – to offer maximum manufacturing flexibility for generator components and sub-systems.

(3) Intelligent Design
The geometric flexibility afforded by AM coupled with difficulties of repairing ODS alloys will drive a third interdependent innovation in OXIGEN. Component design methodologies that focus on function and modular component design will help drive the introduction of new materials, address manufacturing limitations and will impact on a components performance in the following ways:

  • Improved part complexity e.g. by integration of internal channels for cooling or embedded sensors, as well as optimised overall part design.
  • Traditionally expensive manufacturing processes will become cost-effective for smaller sub-components, allowing improved system performance.
  • Selective use of high-cost/high-performance material only where needed, or to overcome specific manufacturing dis-advantages that limit their use.
  • Repair of components by sub-component replacement will become possible; ODS materials are currently difficult (or impossible) to repair.

(4) Embedded fibre optic sensing

Condition monitoring of structural components and machinery at elevated temperatures is a critical issue for both economic and safety reasons.  A prime example of this is in future power generation facilities where the ability to continually assess component health has the prospect of allowing an operator to run a plant at optimum elevated temperatures with extended maintenance intervals whilst avoiding unexpected shutdowns through continuous knowledge of wear and wear rate.  OXIGEN will exploit fibre optic sensing technology to facilitate high temperature sensors for process and condition monitoring.