Combinatorial and high-throughput investigation of growth nanotwin formation

Abstract

This study examines the synthesis of growth nanotwins in CuNi alloys using combinatorial and high-throughput experimental techniques. 338 unique CuNi samples were synthesized via co-sputtering to create a material library encompassing composition, hardness, phase, and crystallographic data. The material library data in conjunction with scanning transmission electron microscopy was used to evaluate growth twinning over a wide compositional range (Cu – 6.8 to 58.8 at% Ni). A direct correlation between measured twin boundary spacings and the stacking fault energies underscored limitations of the current growth twin model caused by an underestimation of the free energy penalty for forming non-twinned grains. To address this, a refined model was developed to accurately capture the variation in twin boundary spacing and formation across all compositions. This model paves the way for high-throughput investigations into nanotwin synthesis in various alloy systems.