The French group Safran is among the world leaders for the manufacture of aircraft and helicopter engines, and therefore an advanced expertise in the field of superalloys metallurgy and processing. This position, shared with General Electric, Pratt & Whitney or Rolls-Royce must be defended, especially with regards to the American supremacy. Within this highly technological field, the industrial competitiveness is closely related to the scientific research progresses. Therefore Safran has decided few years ago to team with academics through mid-term research programs and has co-funded the OPALE ANR industrial chair, selected by the ANR after the 2014 call. This first very fruitful program comes now to its end and one of the outcomes is the definition of a road map for the future.
The new- and next- generation turbomachines must work at higher temperatures to gain better efficiency and in turn reduce the air transport ecological impact, in line with the objectives “Vision 2020” defined by the ACARE. The gamma-gamma' nickel-based superalloys are nowadays the only materials fulfilling the requirements for turbine disks working in the hottest part of the engines; those are among the most critical parts of an engine. The OPALE chair (ANR-Safran 2014-2019) demonstrated that the metallurgical behavior of gamma-gamma' superalloys and in turn the mastery of forging processes are by far much more complex than for formerly used alloys. Those materials will be used in aircraft engines for the next 30 years, at least. Being able to control their microstructure evolution upon forging operations and gain in the knowledge of their in-service behavior appears to be both an absolute need from the industrial perspective, and a great scientific challenge. The ANR industrial chair project TOPAZE aims at facing this wide challenge, with a research program involving two academic teams of renowned expertise in microstructure evolution upon thermomechanical processing at Cemef (MINES ParisTech, Sophia Antipolis) and in microstructure - mechanical behavior and durability relationships at Institut P' (ISAE-ENSMA CNRS, Poitiers). The proposed research, made of both applied and fundamental topics, will lay the groundwork of predictive models for microstructures and properties, which are the indispensable tools of the metallurgy of the future.
The person proposed to be the chair holder, Nathalie Bozzolo, is an experienced scientist with strong connection with industry. Expert in physical metallurgy, and especially in the analysis of microstructural mechanisms, she is at the junction between the two branches of the project: process microstructure and microstructure-properties relationships. The other involved researchers complete the large competency spectrum needed to achieve that ambitious project: from fine material and properties analysis to process-microstructure and microstructure-properties relationship modelling, including the development of new numerical simulation tools and original experimental setups.
Fundamental works (experimental and numerical developments, metallurgical mechanism analysis) will help solving efficiently and originally the industrial issues treated in the works in direct connection with industrial concerns (support for processing new alloys or optimizing new processes). In the long run, the output of the project will be applicable to other types of alloys (titanium-based, aluminum-based, steels) used in aeronautics, but also in other fields like ground transportation or energy. Another important aim of the TOPAZE chair is the education of a new generation of metallurgists to fulfill the recruitment needs of the industry.
Madame Nathalie Bozzolo (ARMINES)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Pprime Institut P' : Recherche et Ingénierie en Matériaux, Mécanique et Energétique
Help of the ANR 700,000 euros
Beginning and duration of the scientific project: December 2019 - 48 Months