Article

Molecular dynamics study of Cu-Pd ordered alloys

Journal of Achievements in Materials and Manufacturing Engineering 01/2008; 31(1).
Source: DOAJ

ABSTRACT

Purpose: The goal of the paper is to study the molecular dynamics of Cu-Pd ordered alloys.Design/methodology/approach: The thermal and mechanical properties of Cu, Pd pure metals and their ordered intermetallic alloys of Cu3Pd(L12) and CuPd3(L12) are studied by using the molecular dynamics simulation. The melting behavior of the metals considered in this work is studied by utilizing quantum Sutton-Chen (Q-SC) many-body potential. The effects of temperature and concentration on the physical properties of Cu-Pd system are analyzed.Findings: A wide range of properties of Cu, Pd pure metals and their Cu3Pd and CuPd3 ordered intermetallics is presented. It was found that this potential is suitable to give the general characteristics of the melting process in these systems. Practical implications: The simulation results such as cohesive energy, density, elastic constants, bulk modulus, heat capacity, thermal expansion and melting points are in good agreement with the available experimental data and other theoretical calculations.Originality/value: To the best our knowledge this work presents, for the first time, a wide range of physical properties of alloys focusing on Cu-Pd ordered compounds.

Download full-text

Full-text

Available from: S. Özdemir Kart
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this investigation, we focused on the effects of pressure on the melting of elements Cu, Pd as well as Pd(3)Cu order alloy. We have performed molecular dynamics based computations of the variation of the physical properties of the elements Cu, Pd and Pd(3)Cu alloy with pressure and temperature. The quantum Sutton-Chen many-body interatomic potentials have been used for these elements, and the standard mixing rule has been used to obtain the parameters of this potential for the alloy state. This molecular dynamics simulation was performed in the NPT ensemble. Our study enabled us to predict the thermodynamic properties such as melting temperature, isobaric heat capacity as well as the lattice thermal expansion. The temperature dependence of energy and density were calculated at high pressure. Moreover, we presented the variation of the melting temperature, heat capacity as well as the thermal expansion of the crystal with pressure. The obtained results showed that the melting temperature increase with increasing pressure and isobaric heat capacity as well as lattice thermal expansion decrease with increasing pressure. Our computed results are in reasonable agreement with the experimental data where they are available.
    No preview · Article · Apr 2010 · Defect and Diffusion Forum
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this investigation, we focus on the melting of elements Cu, Pd as well as Cux–Pd1−x random alloys. The thermodynamic properties such as melting temperature, isobaric heat capacity and lattice thermal expansion coefficient were calculated as a function of pressure in the range of 0–100GPa. Moreover, the temperature dependence of energy, order parameter, volume, and density were calculated in various pressures. These calculations were performed by molecular dynamics simulation technique in NPT ensemble. The results showed melting temperature increase upon increasing pressure. Furthermore, isobaric heat capacity and lattice thermal expansion decreased with increasing pressure. These variations were found to be nonlinear approximating a constant value at higher pressures. Our results are in reasonable agreement with the experimental data where they are available.
    No preview · Article · Jun 2010 · Computational Materials Science
  • [Show abstract] [Hide abstract]
    ABSTRACT: Molecular dynamics (MD) simulations have been performed to investigate the thermodynamic and mechanical properties of Cu–x% Pd (at%) random alloy, as well as those of the Cu3Pd and CuPd3 ordered alloys, in the temperature range from 200 K up to the melting point. The quantum Sutton-Chen (Q-SC) many-body interatomic potentials have been used to describe the energetics of the Cu and Pd pure metals, and a standard mixing rule has been employed to obtain the potential parameters for the mixed (alloy) states. We have computed the variation of the melting temperature with the concentration of Pd. Furthermore, the variation of the cohesive energy, the order parameter, the thermal expansion coefficient, the density, the isobaric heat capacity, the bulk modulus, and the elastic stiffness constants were also calculated at different temperatures and concentrations for these materials. The computed variations of the thermodynamic and mechanical properties with temperature are fitted to a polynomial function. Our computed results show good agreement with other computational simulations, as well as with the experimental results where they have been available.
    No preview · Article · Jun 2010 · Materials Science and Engineering A
Show more