Correlation Between Cluster Structure And Mechanical Properties Of Cu-Zr Based Metallic Glasses

As a new class of advanced materials,metallic glasses has many excellent properties due to its unique microstructure,has a wide range of applications in different fields.For a long time,the research on the correlation between microstructure and elastic properties of metallic glasses has been a hot topic for scholars at home and abroad.The elastic modulus is closely related to the structure,thermodynamics and kinetics,mechanical,physical properties and stability of metallic glasses.Therefore,elastic modulus is an important parameter for studying and understanding the mechanical properties of metallic glasses.Although there has been a lot of research and great progress in the elastic properties of metallic glasses,due to the complexity of the microstructure of metallic glass and the limitations of experimental conditions,the research on the relationship between the microstructure and elastic properties of metallic glasses is very big obstacles.Therefore,establishing quantitative correlation between elastic properties and microstructure of metallic glasses has become an important issue in the field of materials research.In view of the above problems,based on the Heisenberg's uncertainty principle,the quantitative relationship between the elastic modulus,shear modulus and atomic cluster structure of the metallic glasses is derived.It is deduced that the elastic modulus for the system of interest is proportional to the reciprocal of atomic cluster radius(r)fourth power and the square of the effective valence electron number.The correlation reflected by these equation is systematically validated by the available experimental and theoretical results of the Cu-Zr system metallic glasses.The analysis on the effects of different alloy compositions,quenching temperature and cooling rate on the micro-cluster structure and elastic properties of metallic glasses,it is found that with the increase of the proportion of components with smaller elastic modulus,the coordination number of metallic glasses increases,and the atomic structure degree of order increases,the atomic packing is more compact,and the icosahedral cluster with five symmetry is reduced in content,the stability of the system is reduced,and the bulk modulus and shear modulus are also gradually reduced.With the decrease of quenching temperature and cooling rate,the five-time symmetry of the metallic glasses is improved,the structure is more stable,and the bulk modulus and shear modulus are gradually increased.Thereby,a quantitative correlation between the elastic modulus of the metallic glass and the cluster structure is established.