SPIRIT

Title:

Synthesis of ceramic nanoprecipitates in metallic substrate by ion beam co-irradiation 

Scientific frame of the study:

The dispersion of nanoprecipitates of a ceramic phase as for example oxide, carbide or nitride has proved in the last ten years to be an interesting option to improve the thermomechanical, wear and corrosion resistance and radiation tolerance properties of metallic alloys [1, 2]. In the case of irradiation of oxide dispersed strengthened ferritic alloys (ODS), oxide nanoprecipitates act as defect sinks and trapping sites for gas atoms [3]. In the frame of the development of advanced materials to be applied in Generation IV nuclear reactors and nuclear fusion testing reactors, the family of ODS has known a strong growth of interest [4]. Alloys strengthened by precipitation of nanocarbide or nanonitride phases seem to exhibit similar performing properties [5]. 

Aim of the work:

This work can be divided in two complementary steps: 1) the synthesis of a nanoprecipitate dispersion of oxide (Y₂O₃ or ZrO₂), carbide (TiC) or nitride (TiN) in an iron-chromium model alloy by ion beam co-irradiation Y/O, Zr/O, Ti/C or Ti/N followed by an appropriate annealing treatment and 2) the study of the stability of the nanoprecipitate dispersion under high dose ion post-irradiation and high implanted gas content. 

Scientific approach:

Co-irradiation and post-irradiation experiments will be conducted using the ion beams delivered by the three machines from the JANNUS multi-irradiation platform [6]. The irradiation configurations adopted in this work will be derived from the approach developed during the early 2000’s by the german group from Rössendorf to produce SiC nanoprecipitates in Si single crystal by Si and C ion co-irradiation [7]. We intend to study the exact role of the different parameters involved in the ion beam assisted synthesis process such as temperature, dose rate, total dose and metal/non metal ratio.

A very careful characterization task will take place just after the co-irradiation experiment and also after the annealing test. This task will include chemical composition analysis and microstructural investigation based on ion beam analysis (RBS, NRA), X-ray diffraction, Raman microspectrometry and transmission electron microscopy. 

Collaboration:

A collaboration will be developed with the group of L. Thomé from CSNSM Orsay who has a strong experience in the field of ion mixing [8]. 

Duration and appointment:

24 months, between 2 500 and 2 800 €/month 

Tutors:

L. Beck, Y. Serruys and P. Trocellier, JANNUS Laboratory, CEA Saclay, France. 

References:

[1] D. Sakuma et al., J. Nucl. Mater. 329-333(2004)392.

[2] Cheng Guo Wang et al., Mater. Sci. Engin. A308(2001)292.

[3] T. Tanaka et al., J. Nucl. Mater. 329-333(2004)294.

[4] J.L. Boutard et al., C. R. Phys. 9(2008)287.

[5] O.I. Ban’kovskii et al., Por. Metall. 9(1981)51.

[6] P. Trocellier et al., Materials Research Society Symposium Proceedings of the 2010 Fall Meeting, Boston, Paper R7.1.

[7] R. Kögler et al., Nucl. Instrum. Meth. Phys. Res. B206(2003)989.

[8] L. Thomé et al., Nucl. Instrum. Meth. Phys. Res. B121(1997)237.

Contacts: lucile.beck@cea.fr, patrick.trocellier@cea.fr, yves.serruys@cea.fr.