Characterization of Powder Metallurgy (PM) Nickel Base Superalloys for Aeronautical Applications


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During the last decade, some major improvements have been achieved concerning the evaluation of new types of materials suitable for aeronautical components exposed to severe operational conditions, such as turbine disks. Due to their outstanding mechanical properties, nickel base superalloys assumed a preferential position when compared with other conventional metallic alloys, benefiting from both their superior fatigue strength and high temperature behaviour. However, these alloys evince a high sensibility concerning possible defects that can arise due to certain types of loading, such as porosities and cavities associated with creep-fatigue at high temperatures. The present paper compiles some experimental results obtained for two types of recent nickel base superalloys. Some fatigue tests were performed using two configurations of these materials: a set of Udimet 720Li specimens (CT geometry) and a set of RR1000 specimens (CN geometry). A maximum temperature of 650°C was considered in both types of materials. The mechanical properties of these alloys were inferred via typical FCGR parameters, such as da/dN vs K curves, complemented with detailed analyses of the cracking mechanisms based on SEM observations. Finally, some metallographic characterization tests were carried out in order to determine the average grain size of these PM alloys and to confirm the presence of important microstructural constituents that can influence the overall fatigue performance of these materials.



Materials Science Forum (Volumes 514-516)

Edited by:

Paula Maria Vilarinho




J. M. Silva et al., "Characterization of Powder Metallurgy (PM) Nickel Base Superalloys for Aeronautical Applications", Materials Science Forum, Vols. 514-516, pp. 495-499, 2006

Online since:

May 2006




[1] Heisen, W. , Mater. World, Vol. 4, (1996), Ed. IOM, UK.

[2] Harrison, G.F. and Winstone, M.R., Aeroengine applications of advanced high temperature materials, in Mechanical Behaviour of Materials at High Temperature (Ed. Branco, C.M. et al. ), NATO ASI Series Vol. 15 (1996).


[3] Bold, S.E., Technology development for aeroengines, Proc. of DERA symposium, Ed. Farris, P.M. and Winstone M.R., (1999), DERA, Farnborough, UK.

[4] Fecht, H. and Furrer, D.; Processing of Nickel-Base Superalloys for Turbine Engine Disc Applications,; Advanced Engineering Materials Vol. 2, 12 (2000), Wiley VCH Verlag, Weinheim, Germany.


[5] Pineau, A., Fatigue and creep-fatigue behaviour of Ni-base superalloys: microstructural and environment effects, in Mechanical Behaviour of Materials at High Temperature (Ed. Branco, C.M. et al. ), NATO ASI Series Vol. 15 (1996).


[6] Pang, H. T and Reed, P.A. S, Fatigue crack initiation and short crack growth in nickel-base turbine disc alloys-the effects of microstructure and operating parameters, Int. Journal of Fatigue, 25 (2003), Elsevier.


[7] Knowles, D.M. and Hunt, D.W., The influence of microstructure and environment on the crack growth behaviour of powder metallurgy nickel superalloy RR1000, Metall. and Mat. Transactions A, Vol 33 (2002), 3165-3172.


[8] Dubiez-Le Goff, S. , Coutourier, R., Guétaz, L. and Burlet, H., Effect of the microstructure on the creep behaviour of PM Udimet 720 superalloy-experiments and modeling , Materials Science and Engineering A (2004), Elsevier, 599-603.


[9] Tong, T., Dalby, S., Byrne, J., Henderson M.B., Hardy, M.C., Creep, fatigue and oxidation in crack growth in advanced nickel base superalloys, Int. Journal of Fatigue-23 (2001), Elsevier, 897902.


[10] Zhao, L.G., Tong, J., Vermeulen, B., Byrne, J., On the uniaxial mechanical behaviour of an advanced nickel base superalloy at high temperature, Mechanics of Materials-33 (2001) Elsevier, 593-600.


[11] Branco, C.M., Santos, F.B., Byrne, J., Fatigue crack growth at high temperature in the PM nickel base superalloy Udimet 720Li, invited paper, 13 th European Conference on Fracture (2000), Ed. ESIS, UK.

[12] Tong J., Byrne, J., Effects of frequency on fatigue crack growth at elevated temperature, Fat. Fract. Eng. Mater. Struct. -22 (1999), Blackwell Science Ltd, 185-193.

[13] Branco, C.M., Byrne, J., Hodkinson, V., Elevated temperature fatigue crack growth of nickel base superalloys. A review and modelling, in Mechanical Behaviour of Materials at High Temperature (Ed. Branco, C.M. et al. ), NATO ASI Series Vol. 15 (1996).


[14] ASTM E647-95a: Standard test method for measurement of fatigue crack growth rates, ASTM Standards (1995), pp.577-613.

[15] Donald, J.K., Ruschau, J., Direct current potential difference fatigue crack measurement techniques, Fatigue Crack Measurement: Techniques and Applications (1991), Ed. Marsh, K.J., Smith, R.A., Ritchie, R.O., EMAS, UK.