Experimental Measurements of Nucleation Frequency and Crystal Growth Rate in Pd-Cu-Ni-P Metallic Glass

Abstract

AbstractCrystallization mechanism and kinetics of a Pd40Cu30Ni10P20 glass was investigated in a wide temperature range from 603 (near the glass transition temperature) to 764 K (near the equilibrium melting temperature) by using an isothermal annealing treatment for nucleation and growth. The nucleus density (nv) is about 5 × 1013 nuclei/m3 and is independent of annealing temperature. Therefore, it is assumed that the crystallization of the alloy was dominated by heterogeneous nucleation due to “quenched-in nuclei”. On the other hand, the crystal growth rate (Uc) increases from 1.07 × 10− to 5.68 × 10−5 m/s with rising annealing temperature from 603 to 764 K. These values of Uc are 2–3 orders of magnitude larger than the calculated Uc on the basis of Classical Nucleation and Growth Theory (CNT). Furthermore, the glass-forming ability of the alloy will be discussed in the framework of the present results.