Crystallization kinetics and thermal stability of shock-compacted amorphous Ni78P22

Abstract The changes occurring in the structure of shock-compacted amorphous Ni 78 P 22 powder in the pressure range 50–150 kbar were studied. At 50 kbar Ni 78 P 22 does not crystallize, but the increase of pressure causes both crystallization which is completed at 150 kbar and formation of stable crystal Ni and Ni 3 P phases. The minimum porosity (≈2.5%) was obtained at 70 kbar. No shift of crystallization temperature of the amorphous phase, remaining after shock compaction, was registered, but the activation energy of crystallization was somewhat less (≈ 150 kJ/mol) compared to the value corresponding to the crystallization of shock nontreated amorphous powder (212 kJ/mol). It may indicate that shock waves cause a certain “destabilization” of amorphous Ni 78 P 22 .