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Predictive Microstructural Assessment and Micro-Mechanical Modeling of Deformation and Damage Accumulation in Single Crystal Gas Turbine Blading

Objective



European gas turbine manufacturers have a strong need for
improved methodologies for predicting the deformation and
failure of turbine blades for advanced engines with
increased thermal effeciency. Such predictive
methodologies are needed for (i) avoiding catastrophic
failure and also (ii) to assure that the critical
components are utilised most efficiently. Particularly
the full advantage of single crystal superalloys is not
currently being achieved because of a lack of basic
understanding of the anisotropies and defect structures
associated with processing, deformation and failure.
The work proposed here is directed to developing an
improved basis for accounting for the anisotropic
mechanical behaviour of single crystal superalloys under
conditions relevant to service. The present program
represents the first attempt at including the cast defect
structure in a model for predicting deformation and
failure of gas turbine blading. The predictions of the
model will be validated by discriminatory mechanical
testing, such as multiaxial creep and thermal fatigue
tests. The major research tasks are: Establishment of a
database of creep and LCF tests for carefully
characterised crystal orientations, (2) metallographic
identification and characterisation of deformation and
damage mechanisms using OM, SEM and TEM in combination
with image analysis, (3) micromechanical modeling to
establish a physically based life prediction methology
which adresses damage accumulation and failure, (4)
multiaxial and thermal fatigue benchmark testing of
single crystal specimens, including specimen surface
imaging, (5) validation and refinement of a unified
deformation and damage model with the results of (4) and
(6) assessment of the validated model with appropriate
material databases using the multiaxial creep and thermal
fatigue tests of (4) as benchmarks.

The results of the proposed research will increase the
basic understariding of deformation and damage processes
in SX superalloys under complex loading conditions. They
will assist European gas turbine manufacturers in their
efforts to maintain and increase their share of the
international market against fierce competition from the
US and Japan. The consortium of partners involved in the
proposed research obtains a maximum degree of trans
european cooperation between universities (IMPCOL/GB, IM
RUB/DE), research institutes (CNR ITM/IT, ARMINES/FR),
and industry comprised of large (EGT/GB, KWU/DE,
ANSALDO/IT) and small organisations including the
participation of one SME (IMMG, GR). Brite/Euram Keyword
Areas covered by the proposal are A06 (energy / power
generation), B09 (mechanical engineering), C41
(superalloys) and D25 (materials science).

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

Ruhr-Universität Bochum
Address
150,Universit¢tsstraãe 150
44780 Bochum
Germany

Participants (7)

ALSTOM POWER UK LTD.
United Kingdom
Address
Lichfield Road
ST17 4LN Stafford
ANSALDO ENERGIA SPA
Italy
Address
Via Nicola Lorenzi 8
Genova
ASSOCIATION POUR LA RECHERCHE ET LE DEVELOPPEMENT DES METHODES ET PROCESSUS INDUSTRIELS
France
Address
Enceinte Snecma Evry-corbeil 032
91003 Evry
Consiglio Nazionale delle Ricerche
Italy
Address
Via Induno 10
20092 Cinisello Balsamo Milano
IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
United Kingdom
Address
Royal School Of Mines, Prince Consort Road
SW7 2BP London
INSTITUTE OF MECHANICS OF MATERIALS AND GEOSTRUCTURES S.A.
Greece
Address
22,Askiton Street 22
15236 Athens
Siemens AG
Germany
Address
35,Wiesenstraße 35
45466 Mülheim An Der Ruhr