Ab initiostudy of tension-shear coupling in NiAl

Abstract

Results of a density functional theory study of the coupling between tension and shear processes are presented. The coupling potential was derived from calculations of generalized stacking fault energies in combination with cleavages preopened by tension. The effect of tension-shear coupling is studied for various slip systems of the intermetallic compound NiAl. We derive an atomistic potential for the tension-shear coupling, which accounts for slips associated with partial dislocations. The derivation goes beyond the formulation of Sun et al. ͓Mater. Sci. Eng., A 170, 67 ͑1993͔͒ by including the next term of the Taylor expansion of the tension-shear coupling potential. This potential is able to describe the tension softening of ͗111͑͘110͒ partial dislocations reasonably well.

Ductility and magnetism: An ab-initio study of NiAl–Fe and NiAl–Mn alloys

“…Again, this is in accordance with the calculations, which show that NiAl-Fe Ni has g us -in both slip systems considered -higher than pure NiAl. It may be noted that alloying into Ni sites was found ineffective -if better ductility is of concern -also for Cr, Mo, Ti, and Ga additions [33].…”

“…The atomic positions were always fully relaxed in order minimize the tensile stress in direction perpendicular to a slip plane [19,20]. The overall volume of the supercell was kept constant during the slip, in order to have well-defined conditions focusing on the interactions at the interface.…”

Cleavage tendency of anisotropic two-dimensional materials:ReX2(X=S,Se) andWang1, Liu2, Wang3 et al. 2017Phys. Rev. B571470View full textAdd to dashboardCite

“…Ecl is defined as the minimum energy required to overcome interlayer force during exfoliation processes [37,38]. The structure of the bulk ReS2 is shown in Figure 5(a), where the side surfaces {100} and {010} represent the surfaces containing the 0°and 60°directions, respectively.…”

Effect of O impurity on structure and mechanical properties of NiAl intermetallics: A first-principles study

“…Many attempts have been made in order to improve the room temperature ductility of NiAl by investigating effects of microalloying, macroalloying and reinforcing ductile second phase [3][4][5][6][7][8][9]. Despite these attempts, the room temperature brittleness is still a key problem for the application of NiAl.…”