Anisotropy of tensile strength and fracture mode of perfect face-centered-cubic crystals

Abstract

Atomic diffusion bonding of wafers with thin nanocrystalline metal films

Intrinsic Strength Asymmetry Between Tension and Compression of Perfect Face-Centered-Cubic Crystals

“…which is the unified tensile fracture criterion [27] and had been used in our previous work [26]. Combining Eqs.…”

“…When r A equals the ideal tensile strength r T or the ideal compressive strength r C , fracture happens. In order to calculate the ideal strength for loading along an arbitrary crystallographic direction, a universal fracture criterion for high-strength materials, in which both the tensile and compressive normal stress effect are considered, can be employed [26,29]. According to this criterion, the fracture occurs along a specific plane if satisfying…”

“…Supposing that a uniaxial stress r A , tension or compression is performed on a perfect single-crystal specimen [26], then the corresponding normal stress r and shear stress s along a certain crystallographic plane could be denoted as…”

“…While Tschopp and McDowell [2,22] calculated the t/c asymmetry of the critical stresses for the occurrence of homogeneous dislocation nucleation in Cu perfect crystal with molecular dynamic (MD) method, the fracture of perfect crystal that homogenously deforms without the aid of dislocations and other defects has not been considered. And neither of the two studies mentioned above is paid attention to the competition between different crystallographic planes, such as the shear of {111} plane and the cleavage of {100} plane, which could lower the tensile strength along some specific loading orientations [26]. Available In this study, firstly we applied the raw data of ideal cleavage strength and shear strength of six fcc crystals (Cu, Au, Ni, Pt, Al and Ir) with the fracture criterion [27][28][29] to calculate the ideal compressive strength along an arbitrary direction.…”

“…Available In this study, firstly we applied the raw data of ideal cleavage strength and shear strength of six fcc crystals (Cu, Au, Ni, Pt, Al and Ir) with the fracture criterion [27][28][29] to calculate the ideal compressive strength along an arbitrary direction. Then, the t/c asymmetry was achieved with the presently obtained ideal compressive strength and the previous results of ideal tensile strength [26]. Finally, the orientation-dependent t/c asymmetries of the studied six crystals are analyzed.…”