Simulation of Diffusion Bonding of Different Heat Resistant Nickel-Base Alloys

Currently, an important fundamental problem of practical importance is the production of high-quality solid-phase compounds of various metals. This paper presents a theoretical model that allows one to study the diffusion process in nickel-base refractory alloys. As an example, a two-dimensional model of ternary alloy is considered to model diffusion bonding of the alloys with different compositions. The main idea is to divide the alloy components into three groups: (i) the base element Ni, (ii) the intermetallic forming elements Al and Ti and (iii) the alloying elements. This approach allows one to consider multi-component alloys as ternary alloys, which greatly simplifies the analysis. The calculations are carried out within the framework of the hard sphere model when describing interatomic interactions by pair potentials. The energy of any configuration of a given system is written in terms of order parameters and ordering energies. A vacancy diffusion model is described, which takes into account the gain/loss of potential energy due to a vacancy jump and temperature. Diffusion bonding of two dissimilar refractory alloys is modeled. The concentration profiles of the components and order parameters are analyzed at different times. The results obtained indicate that the ternary alloy model is efficient in modeling the diffusion bonding of dissimilar Ni-base refractory alloys.