Quaternary systems of Ni-Al-Cr-X type, where X indicates one of alloying elements typical for Ni-base superalloys, are studied as model cases of real materials. Experimental and theoretical study of phase equilibria in these systems is of practical importance for development of new prospective materials with excellent high temperature mechanical properties resulting from the coexistence of disordered matrix (gamma) and coherent ordered domains (gamma prime).
In this work we report the results of our study on series of Ni-Al-Cr-Ti alloys after long term annealing at 1173 K and another group of Ni-Al-Cr-Co alloys annealed at 1373 K. This research continues our previous work on similar alloys annealed at different temperatures [1-3]. Thermodynamic modelling of phase equilibria was performed using ThermoCalc software package with commercial database for Ni-base superalloys [4]. Experimental study of the alloys was done by means of analytical transmission and scanning electron microscopy. The comparison of new experimental data with theoretical calculations and with other data found in the literature is given.
Grateful acknowledgement goes to the Grant Agency of the Czech Republic for the financial support under projects No. 106/02/0876.
[1] P. Brož, J. Buršík, M. Svoboda and A. Kroupa: Mat. Sci. Eng. A 324 (2002) 28-33.
[2] P. Brož, J. Buršík and R. Picha: Intermetallics 10 (2002) 635-639.
[3] R. Picha, P. Brož and J. Buršík: J. Alloys and Comp. (2004) in print.
[4] N. Dupin and B. Sundman: Scan. J. Metall. 30 (2001) 184-192.