%0 journal article
%@ 0925-8388
%A Chen, Y,H.,Rogstroem, L.,Ostach, D.,Ghafoor, N.,Johasson-Joesaar, M.P.,Schell, N.,Birch, J.,Oden, M.

%D 2017
%J Journal of Alloys and Compounds
%N 
%P 1024-1032 
%R doi:10.1016/j.jallcom.2016.08.299
%T Effects of decomposition route and microstructure on h-AlN formation rate in TiCrAlN alloys
%U https://doi.org/10.1016/j.jallcom.2016.08.299
 
%X The phase evolution of cubic (c), solid solution TixCr∼0.37Al1−0.37−xN alloys with x = 0.03 and 0.16, and the kinetics of the hexagonal (h)-AlN formation are studied via in situ wide angle x-ray scattering experiments during high temperature (1000–1150 °C) annealing. Spinodal decomposition was observed in Ti0.16Cr0.36Al0.48N while Ti0.03Cr0.38Al0.59N decomposes through nucleation and growth of h-AlN, c-TiN and c-CrAlN. h-AlN is formed from c-CrAlN domains in both cases and the formation rate of h-AlN depends on the stability of the c-CrAlN domains. In Ti0.16Cr0.36Al0.48N, the c-CrAlN domains are stabilized by crystallographic coherency with the surrounding c-TiCrN in a microstructure originating from spinodal decomposition. This results in lower formation rates of h-AlN for this composition. These differences are reflected in higher activation energy for h-AlN formation in Ti0.16Cr0.36Al0.48N compared to Ti0.03Cr0.38Al0.59N. It also points out different stabilities of the intermediate phase c-CrAlN during phase decomposition of TiCrAlN alloys. Additional contributions to the low activation energy for formation of h-AlN in Ti0.03Cr0.38Al0.59N stems from precipitation at grain boundaries.