Molecular-dynamics study of ductile and brittle fracture in model noncrystalline solids

Article

关键词: BULK METALLIC-GLASS;    PLASTIC-DEFORMATION;    CANONICAL ENSEMBLE;    AMORPHOUS SOLIDS;    STRAIN-RATE;    FLOW;    TEMPERATURE;    TRANSITION;    RELAXATION;    ALLOYS;   

DOI  :  10.1103/PhysRevB.60.7062

来源: SCIE

【 摘 要 】

Molecular-dynamics simulations of fracture in systems akin to metallic glasses are observed to undergo embrittlement due to a small change in interatomic potential. This change in fracture toughness, however, is not accompanied by a corresponding change in flow stress. Theories of brittle fracture proposed by Freund and Hutchinson indicate that strain rate sensitivity is the controlling physical parameter in these cases. A recent theory of viscoplasticity in this class of solids by Falk and Langer further suggests that the change in strain rate sensitivity corresponds to a change in the susceptibility of local sheer transformation zones to applied shear stresses. A simple model of these zones is developed in order to quantify the dependence of this sensitivity on the interparticle potential. [S0163-1829(99)09733-7].

【 授权许可】

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