Anisotropic mechanical characteristics of Cu6Sn5 micro-cantilever under bending load

Based on the density functional theory (DFT), in this study, the elastic constants of single-crystal Cu6Sn5 and the elastic modulus, shear modulus, bulk modulus, and Poisson's ratio of polycrystalline Cu6Sn5 were calculated first, and the calculated mechanical properties of polycrystalline Cu6Sn5 were close to the previous experimental values. Then, the anisotropic and isotropic mechanical behaviors of Cu6Sn5 micro-cantilevers were characterized by three-dimensional finite element analysis (FEA). Simulation results show that, the maximum values of the first principal stress in the isotropic case and in the anisotropic case are located at the bottom of the micro-cantilever, while the maximum shear stress and maximum equivalent stress are located at the edge of the contact area between the micro-cantilever and the indenter. Compared with the result of isotropic case, crystal orientations have influence on the maximum first principal stress under anisotropic case, while they have limited effect on the maximum values and distributions of maximum shear stress and von Mises stress.