Characterization of Oxide Growth on Surface of Al-Mg-Si Welded Joint

Table 3

The possible chemical reaction and standard Gibbs free energies during oxidation at 600°C.

Reaction	−Δ𝐻 (J/g·mole)	−Δ𝑆 (J/g·mole·°K)	Δ𝐺^∘600 (kJ)
2Mg + O2(g) → 2MgO	1,219,140	233.04	−1,015.68
(0.5)Mg + Al + O2(g) → (0.5)MgAl2O4	1,164,035	218.84	−972.98
4/3 Al + O2(g) → 2/3 Al2O3	1,121,922	215.47	−931.66
2Mg + Si → Mg2Si	155,600	−75.0	−90.12