J Mater Sci Technol ›› 2011, Vol. 27 ›› Issue (6): 534-538.

• Mechanical and Functional Properties of Materials • Previous Articles     Next Articles

Effect of Minor Alloying on Crystallization Behavior and Thermal Properties of Zr64.5Ni15.5Al11.5Cu8.5 Bulk Amorphous Alloy

Muhammad Iqbal1), Javed Iqbal Akhter1), Haifeng Zhang2), Zhuangqi Hu2)   

  1. 1) Microstructural Studies Group, Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), P.O. Nilore, Islamabad, Pakistan
    2) Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2010-06-17 Revised:2011-01-07 Online:2011-06-28 Published:2011-06-22
  • Contact: M. Iqbal

Abstract: Minor alloying plays an important role in the synthesis and improvement of thermal stability of bulk metallic glasses (BMGs). The present study was conducted to investigate the effect of minor additions of Y, Ti and Nb on crystallization behavior and thermal properties of Zr64.5Ni15.5Al11.5Cu8.5 base alloy. Thermal parameters and the activation energies for crystallization were calculated for four [Zr0.645Ni0.155Al0.115Cu0.085]100-xMx (M = Y, Ti and Nb while x = 0, 2 at. %) alloys. Parameters describing thermal stability in these systems, including the activation energies for crystallization, were determined. The present alloys have wide supercooled liquid region of ≥87 K. Maximum activation energy was found to be greater than 300 kJ/mol for the base alloy. Four crystalline phases were identified in the samples annealed at 823 K. Reduced glass transition temperature (Trg) and other thermal parameters like γ, δ and β improved by Y and Ti addition. Niobium addition resists crystallization below annealing temperature 713 K however its effect on thermal properties is not very promising.

Key words: Activation energy, Thermal properties, Glass-forming ability, Thermal stability, Precipitation, Microstructure