Modeling anisotropic mechanical properties and creep behavior of Ni()/Ni3Al() single crystal superalloys at high temperatures

This research studies the atomistic phenomena causing anisotropy and orientation dependence of mechanical characteristics and creep deformation in Ni(\(\gamma\))/Ni₃Al(\(\gamma'\)) superalloys with single crystals at extreme temperatures. For a wide variety of temperature conditions, stress, and load directions, MD simulations are used. As a result of this investigation, we can better understand how dislocations and elevated-temperature diffusional processes contribute to creep at the tiny scales. Tensile simulations are performed first at constant strain rates of 5 × 10⁰⁹ and 1 × 10¹⁰ 1/s. At stress values between 1.5 and 5.0 GPa, creep simulations are then carried out. Temperatures ranging from 1100 to 1700 K are applied. Additionally, the crystallographic orientations [010], [110], and [111] are considered to be loading directions. Dislocation accumulation in γ channels, shearing of γ′ precipitates, micro-twinning, as well as dislocation climbing through diffusion, which allows them to circumvent precipitates, and γ′ rafting, which is a term used to refer to the coarsening of precipitates that occurs in a directional manner, are all examples of deformation processes seen in each orientation model. This research shows that the findings are in accord with the experimental evidence. Constant strain rates in the steady-state creep phase are derived for each creep model. Power-law equations are used to forecast strain rates based on temperature and other variables such as stress exponent. Based on the values for stress exponent, the map for creep deformation of different load orientation models is presented.