Troisiéme Conférence Européenne sur les Matériaux et les Procédés Avancés
J. Phys. IV France 03 (1993) C7-271-C7-276
Precipitation kinetics in N18 P/M superalloy : experimental study and numerical modellingN. GAYRAUD1, F. MORET1, X. BAILLIN1 and P.E. MOSSER2
1 CEREM/Laboratoire de Génie des Matériaux, CENG - 85X 38041 Grenoble cedex, France
2 SNECMA, 291 av. d'Argenteuil, 92230 Gennevilliers, France
Heat treatments of aeronautical turbine disks produced by powder metallurgy include γ' solutionning, quenching and subsequent annealing. In the present work, the intragranular γ' precipitation kinetics during the quench has been followed by dilatometry and transmission electron microscopy. The precipitation steps are studied on specimens "hyperquenched" from selected temperatures during a simulated industrial quench. Experimental results are compared with a pseudo-binary model based on classical homogeneous nucleation and coarsening theories. While the precipitate volume fraction is lower than 20%, a good quantitative agreement is observed.
© EDP Sciences 1993