High-throughput Atomic Simulation Of Point Defect Structures In Hexagonal Close-packed Metals

With the further development of materials research,high-throughput computing plays an increasingly important role in computational materials science.The microstructures of materials and the effects of these microstructures on the properties of materials can be studied by high-throughput calculations at atomic scale.Under irradiation conditions,a large number of point defects will be formed in metal materials.After a long time of migration or aggregation,these point defects will form various point defect clusters or voids.These clusters or voids will lead to changes in micro-structure,which will change the macro-mechanical properties of materials.Zirconium and titanium are closely packed hexagonal metals,which are widely studied in the field of molecular dynamics and statics.Zirconium material is an important core structure material,which is the key to ensure the safe and efficient operation of nuclear reactor.Titanium metal is also widely used in aerospace and medical engineering.Experiments show that deformation is achieved by forming interstitial dislocation rings on prism surface,vacancy rings on base surface and vacancy annihilation on dislocation and grain boundary.It can be seen that the effect of point defects on the mechanical properties of metal is significant,but it is difficult to observe the structural characteristics of point defects such as vacancies or interstitial and their evolution process in experiments.In this paper,the stable and metastable configurations of vacancies and interstitial clusters in zirconium were studied by means of molecular dynamics,and ART search system.The formation and binding energies of each configurations were calculated,and the curve,analyze the rule according to the configuration structure and curve.It is found that the small and medium vacancy cluster configurations in zirconium metal are mainly planar symmetrical.With the increase of vacancy number,the cluster configurations gradually evolve into three-dimensional space symmetrical structures.The most stable cluster configuration in different numbers have high symmetry,and the medium number cluster configurations contain small vacancy cluster configurations.On the contrary,the most stable interstitial cluster configurations are planar and symmetrical,and the pentra-interstitial cluster configurations have the lowest binding energy and high symmetry.small number of interstitial cluster configurations are included in the middle number of interstitial cluster configurations.Titanium and its alloys form point defects in the process of processing,production and use,which affect the working performance of titanium.In this paper,the stable and metastable configurations of vacancies and interstitial clusters with different sizes of titanium are studied by ART search.It is found that the most stable configuration ofeach vacancy cluster in titanium metal is the same as that of each vacancy cluster in zirconium metal.Large size vacancy cluster configurations contain small number of vacancy cluster configurations and medium number of vacancy cluster configurations are spatially symmetric.The interstitial atoms and vacancies in the most stable configurations of interstitial clusters are distributed in the same plane and symmetrical structure,which is the same as that in zirconium metal,and the large-sized interstitial cluster configurations also contain small-sized interstitial cluster configurations.