The formation of the crystalline phases is discussed with respect to the glass forming ability and thermal stability of the glass phase. In addition to the well known intermetallic Be 2Zr phase and a quasicrystalline phase, three further previously unknown crystalline phases are identified and described in terms of their structure and composition.
It is found that this pre-annealing strongly influences the crystallization sequence and depending on the pre-annealing time leads to preferential formation of different phases. In order to separate formation of crystalline phases from each other, long term isothermal pre-annealing below the glass transition temperature of Zr 46.8Ti 8.2Cu 7.5Ni 10Be 27.5 bulk metallic glass prior to crystallization was performed. Crystallization of metallic glasses often leads to the simultaneous formation of different metastable crystalline phases that makes their identification difficult. Knowledge of the crystallization sequence of metallic glasses can yield a deep insight into the origin of their thermal stability.
0 kommentar(er)
