Thermo-mechanical study of rapidly solidified NiNbZrTiAl amorphous metallic alloys

The thermal stability and viscous flow behaviour of fourrapidly solidified NiNbZrTiAl amorphous metallic alloys under constant heating rate conditions are studied using thermomechanical analyzer (TMA). The viscous flow results are discussed and interpreted in the framework of the Free Volume Model (FVM). The obtained values of FVM parameters are used for estimation of the glass forming ability (GFA) on the basis of the parameter of Angell. The lowest value of Angell's parameter mA (highest GFA) possesses the alloy Ni58Nb10Zr13Ti12Al7. The fracture strength of the alloys studied was estimated on the basis of their correlation with the alloys glass transition temperature Tg according to the equation of Yang. It was determined that the maximum fracture strength possesses the alloy Ni58Nb25Zr8Ti6Al3.