Influence of carbon on energetics, electronic structure, and mechanical properties of TiAl alloys

Abstract We present first-principles calculations of carbon-doped TiAl alloys. The effect carbon on the structural, electronic, and elastic behavior γ phase ( L 1 0 structure) is investigated. calculated enthalpy formation at zero temperature indicates that atoms favor to occupy rather interstitial than substitutional positions. computed solubility in stoichiometric very low, agreement with experimental findings. However, it significantly enhanced for Ti-rich alloy when located inside Ti 6 octahedra. Mechanical properties such as Cauchy pressure, anisotropy, Young’s modulus, well Pugh Poisson ratios off-stoichiometric compositions are analyzed a function concentration its location. As general trend, we obtain below 3 at.%, plays minor role changing ductile -TiAl. A slight increase ductility found γα if either Ti-plane (Ti 4 Al 2 octahedral site) or