Investigation Of Mechanical Property Of Zirconium Based Alloys And Applications Of High-Throughput Methods

We have investigated the mechanical property of zirconium based alloys by using the first-principles methods. For Zr8Ti8 random alloy, we found a fact that the mixing energy can transform from a positive value to a negative value at 430℃ by considering both vibrational and configurational contributions. This result can explain a disagreement between theoretical and experimental results in describing thermodynamic properties of Zr8Ti8. When describing the strain-stress curves of perfect crystals, we found these curves possess step-like changes. There are no defects in crystals, and thus the phenomenon can not be explained by traditional defect theory. We explained the phenomenon successfully by comparing the change of electron occupations and density of states.In studying Zr-Ti, Zr-Hf and Zr-Sc random systems, our results show that the mechanical property almost linearly changes with concentration in Zr-Hf and Zr-Sc systems, while it exhibits nonlinear dependence on concentration in Zr-Ti system. In addition Ti can considerably enhance the ductility of Zr at concentration 0.43. Moreover, the mechanical properties can be attributed into two parts i.e., alloying constituents and alloying effects, which can be well described as a function of alloying composition by a quadratic function:y= MZr (1-x)+Mxx+(x-x2)F. With this function, the mechanical properties of Zr-X alloy systems can be quickly and accurately obtained at any concentration, which would provide a powerful tool to design and select alloy materials.There are so many zirconium based alloy systems that it is hard to investigate them by first-principles methods. Hence in the present paper, we took the idea of Materials Genome Initiative, using high throughput calculating methods to study those systems as well as constructing a corresponding database. As a result, we have designed a high throughput calculating platform HCPMPRA (High-throughput Calculating Platform of Mechanical Properties for Random Alloys). This platform is written with Fortran 90 and Linux Shell, which can be executed in most of Linux environment. It can generate structures, control calculating and analysis data automatically. At the same time, all the calculated data were saved in database.