ICME for Advanced Light-Weight Metal Materials: Case Studies

William Yi Wang *, Chengxiong Zou, Ying Zhang, Bin Tang, Ruihao Yuan, Jun Wang, Hongchao Kou, and Jinshan Li

School of Materials Science and Engineering, Northwestern Polytechnical University, 710072

ABSTRACT: With the release of the Materials Genome Engineering, there are a series of novel professional data sharing and data mining infrastructures and repositories for scientist and engineers.  Accordingly, the basic module combining the material properties will be the essential part to complete and further optimize the MGE strategies.  Based on the density functional theory, first-principles calculations have become an important technology in this module, which can not only provide an insight into the physical mechanisms of typical phenomenon/behavior but also quantitatively predict the thermodynamic, kinetic, and mechanical properties.  Recently, it has been successfully utilized in the development of advanced light-weight high-strength Al alloys, high-entropy alloys, and superalloys.  Through integrating computational materials engineering strategies, it can also be used to investigate the basic properties of alloys, including structural evolution, elastic properties, plastic properties, grain boundaries, stacking faults, anti-phase boundaries, hardness, the creep resistance, and so on, thus, to support a great amount of valuable data for the design of advanced light-weight metal materials.

       This work was financially supported by the National Key Research and Development Program of China, which named the Integration of Computation and Fabrication of Ti-based Alloys.  The main target is to present a case study of high-strength Ti alloys through integrating bottom-up computational design and top-down engineering validation.  Based on high-throughput first-principles calculations, a systematic and comprehensive study on lattice parameters, lattice distortions, stacking fault energies, bonding charge density and electron work function (EWF) has been completed, addressing the power-law relationship in the prediction of yield strength in terms of EWF, building the basic database and supporting essential information to optimize the composition via machine learning algorithms.  Here, in line with the effect of solutes (X) on the phase stability, those solutes are classified into three categories, such as α-phase stablelizer (Al, Ce, Ga, Ge, La, N, Nd and O), β-phase stablelizer (Co, Cr, Cu, Fe, Mn, Mo, Nb, Ni, Pd, Si, Ta, V, and W), and other elements (B, C, Sn, and Zr).  In particular, effects of solutes on the properties of high-strength Ti-7333 andTi-5553 alloys have been studies, which include their segregation behaviors at intrinsic and extrinsic stacking faults, lattice parameters, lattice distortion energies, and stacking fault energies.  In the view of bonding charge density, the atomic and electronic basis was provided to insight into the local HCP-FCC phase transformation of the faults layers.  Correspondingly, it was revealed that Mo atom could dramatically decrease the stacking fault energy, thus, to make theβ-phase more stable.  In line with the d-orbital theory, this work has optimized our proposed novel strategy in developing the advanced high-strength Ti alloys in views of electronics and energetic.

Keywords: High throughput first-principles calculation; ICME; High strength Ti-based alloy;  bonding charge density