Statistical mechanical studies of Al rich Al–Cu melts

Abstract

We evaluate the microscopic correlation functions in Al1−xCux melts (x= 0.10, 0.17, 0.25, 0.33 and 0.40) in the attractive and repulsive region of the square well (SW) potential under the mean spherical model (MSM) principle. We derive the temperature and concentration dependent transport coefficients through the computed structural functions and verify the Dzugutov’s scaling law in Al1−xCuxliquid alloys. The liquid Al-Cu alloys follow the Stokes–Einstein relation especially in Al-rich melts. The concentration–concentration fluctuations in the long-wavelength limit, i.e. SCC(0) and the Warren–Cowley short-range order parameters, α1 have been computed which explains the compound forming behavior in this melts. SCC(0) is also employed to determine the thermodynamic factor for calculating inter-diffusion coefficients from Darken’s approach in liquid alloys. The temperature variation of diffusion coefficients are being applied for the computation of activation energy in liquid Al-Cu alloys by following Arrhenius equation. The theoretically evaluated activation energies of the alloys are in fair agreement with reported values. The composition dependent surface tension is determined and compared with the available experimental results which are in satisfactory agreement. Thus we establish a closer relationship between structure, transport and surface properties in Al1−xCuxmelts without using any adjusting parameters.