| Bulk amorphous alloy is a kind of novel metal material whose unusual atom structure contributes to its excellent performance such as high strength, high rigidity, decay resistance, wear resistance and the capability that is easy to form net shaping etc. In this thesis, in order to acquire bulk amorphous alloy constituted of Zr41.2 Ti13.8Cu12.5Ni10Be22.5, arc melting in graphite crucible process is introduced. Deformation mechanism of the alloy is analyzed based on free volume model. Consequently the yield criterion obeyed by the process of the deformation is investigated. Thus, the plastic constitutive equation that is correlated the yield criterion is evolved. Many research results are achieved as mentioned below.After the process of preparing bulk amorphous alloy by arc melting copper molding process is improved, bulk amorphous alloy (Zr41.2Ti13.8Cu12.5Ni10Be22.5) samples sized of 020X90 mm are prepared by using graphite crucible. The amorphous characteristics of the samples are verified via academic methods, such as X-ray analysis, transmitting electronic microscopy and thermodynaniic analysis.The variation regularity and the interaction effects between shear stress and free volume concentration as well as the effect of strain rate are analyzed in the homogenous deformation process by using numerical value according to Speapen's flow equations of free volume model and referring to the free volume concentration as parameter. The shear band forming mechanism of inhomogenous deformation is studied that is the inhomogeneity distribution of free volume in the material results in acceleration of the local free volume concentration increasing, reducing the viscosity and softening the material, eventually strain localization comes into being along the shear direction.According to the serrated flow investigation in the compress test of the bulk amorphous alloy (Zr41.2Ti13.8Cu12.5Ni10Be22.5), the results of calculation are that the local temperature increasing in the forming process of the shear band augment as the shear energy increases; when the temperature arrives at or exceeds the glasstransition temperature, the local viscosity will be reduced, so does the shear resistance, and the elastic strain energy will force the shear band propagating continually, eventually fracture is formed. Thus, the relation between the serrated flow and the fracture put forward by professor Wright is explained.The view about the phenomenon that the tensile fracture plan deviates from the 45?plane of the maximum shear stress is followed by Coulomb criterion that is acknowledged by people for many years is corrected. By inspecting the surface of high temperature tensile alloy (Zr41.2Ti13.8Cu12.5Ni10Be22.5) sample, that the local part of the deformation region becomes thin along with the thickness direction before the fracture is found, and this process is what is called "necking". According to Mises yield criterion and the theory of disconnected curve of slip line field, the angle between tensile fracture plane and the load axis of the necking material is 54.7. The angle accords to the experimental result (52~56) measured from the bulk amorphous alloy sample. It is to say that bulk amorphous alloy follows Mises criterion in such condition.The bulk amorphous alloy does not follow any criterion of the Mises, Tresca and Coulomb completely. In tensile state and compression state, the yield of bulk amorphous alloy (Zr41.2Ti13.8Cu12.5Ni10Be22.5) follows Mises criterion and Coulomb criterion respectively. However, in the state that includes shear stress, the yield strength is located between the traces of Mises criterion and Tresca (Coulomb) criterion. In order to reflect accurately the yield behavior of bulk amorphous alloy, the United Strength Theory established by Chinese scholar is introduced in the research. The results are that the yield condition of the bulk amorphous alloy and the yield trace on the plane are obtained.To add to all this, the approximate elasto-plastic constitutive relation of the bulk amorphous al...
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