Atomic Structure, Energy Distribution, and Short-Range Order in Symmetric Grain Boundaries of Ni_3Al Intermetallide

摘要

We know that metals and alloys are polycrystalline in their regular state. The grain boundaries, which are a fundamental structural element of polycrystals, determine many of their physicomechanical properties: plasticity, diffusion, recrystallization, decomposition, strengthening, etc. The influence of the grain boundaries on the properties of polycrystals rests on processes such as grain-boundary slip and interaction of the boundaries with various defects (dislocations, vacancies, interstitial atoms, etc.). To understand the processes that involve grain boundaries, we must understand their atomic structure. Computer simulation is the best approach here. The intermetallide Ni_3Al may be distinguished from many similar ordered alloys by the positive temperature dependence of its yield point. Consequently, this alloy is used in industry as a high-temperature and high-strength structural material.