The effects of vacancies in the mechanical properties of tungsten: A first-principles study

Both mechanical and structural properties of bcc crystal tungsten in presence of mono and divacancy defects has been investigated by using accurate first-principles total energy methods based on density functional theory. A model for tungsten containing a concentration of vacancies of about 2% and 4% has been developed and used to compute the maximum tensile stress required to reach elastic instability under increasing load. Moreover stress effects on the crystalline structure have been characterized in terms of structural displacements.