Determination of the Solid-Liquid Interface Energy in the Al-Cu-Ag System

Abstract

The solid-liquid interface energy, r SL , is of major importance during phase transformation. It has a strong influence on solidification morphologies and the final grain structure. The ''grain boundary groove in an applied temperature gradient'' method developed by Gu¨ndu¨z et al. [6] was found to be suitable for measuring the solid-liquid interface energy in ternary alloy systems (e.g., Al-Cu-Ag). In order to measure the solid-liquid interface energy, a radial heat flow apparatus was constructed and assembled. This apparatus ensures a stable temperature gradient for hours and leads to grain boundary grooves in chemical equilibrium. After rapid quenching, the samples were metallographically prepared and the local curvature of the grooves was analyzed.To determine the interface energy, the Gibbs-Thomson equation was used, which requires the local curvature of the grain boundary grooves and the adherent local undercooling obtained from heat flux simulations on the scale of the grooves.

Determination of interfacial energies for solid al solution in equilibrium with Al-Cu-Ag liquid

“…A comparison of the values of the Gibbs-Thomson coefficient (Γ), solid-liquid interfacial energy (σ SL ) , and grain boundary energy (σ gb ) for solid Al solution in the Al-Cu-Ag alloy obtained in the present work with the values of Γ, σ SL and σ gb for solid Al solution phase in the Al-Cu-Ag and Al-based binary alloys determined in previous investigations is given in Table 4. As seen in Table 4, the resulting values of Γ, σ SL , and σ gb for solid Al solution in the Al-Cu-Ag alloy agree very well with the values of Γ, σ SL , and σ gb obtained in the Al-based binary alloys in the limits of experimental errors but disagree with the values Γ, σ SL , and σ gb obtained by Bulla et al [25]. The value of Γ for solid Al solution in the Al-CuAg were found by Bulla et al [25] to be in the range of 4.4 × 10 −8 -8.1 × 10 −8 Km.…”

“…As seen in Table 4, the resulting values of Γ, σ SL , and σ gb for solid Al solution in the Al-Cu-Ag alloy agree very well with the values of Γ, σ SL , and σ gb obtained in the Al-based binary alloys in the limits of experimental errors but disagree with the values Γ, σ SL , and σ gb obtained by Bulla et al [25]. The value of Γ for solid Al solution in the Al-CuAg were found by Bulla et al [25] to be in the range of 4.4 × 10 −8 -8.1 × 10 −8 Km. The statistical fluctuation in their determination of Γ is approximately 85 % [25].…”

“…The value of Γ for solid Al solution in the Al-CuAg were found by Bulla et al [25] to be in the range of 4.4 × 10 −8 -8.1 × 10 −8 Km. The statistical fluctuation in their determination of Γ is approximately 85 % [25]. As shown in Table 4, the average value of Γ for solid Al solution obtained by Bulla et al [25] was about three times smaller than the average value of Γ for solid Al solution obtained in the present study and in previous investigations.…”

“…Bulla et al [25] also measured the thermal conductivity of the solid phase by means of the Laser-Flash method and differential scanning calorimeter, and determined the specific entropy change per unit volume using the Thermo-Calc soft- In the present study, the value of ∆S f for the same solid phase determined using the thermophysical properties of the solid Al solution phase in the Al-Cu-Ag alloy was found to be 0.61 × 10 6 J m −3 K −1 . A comparison of the value of ∆S f for solid Al calculated in the present work with the values of ∆S f for solid Al solution in different binary or ternary alloys is also given in Table 4.…”

The Experimental Determination of Interfacial Energies for Solid Zn in Equilibrium with Zn-Al-Sb Liquid

“…Since 1985, a technique for the quantification of solid-liquid interfacial energy from the grain boundary groove shape has been used. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Observation of groove shape in a thermal gradient can be used to determine the interfacial energy, independent of the grain boundary energy because the interface near the groove must always satisfy…”