This dataset supports the publication “The Effect of Carbon and Silicon Variation on the Microstructure and Mechanical Properties of a Cobalt-Based Superalloy” in Metallurgical and Materials Transactions A. It comprises data for the four cobalt-based alloys investigated in the study, which vary in carbon and silicon content, and corresponding to figures presented in the manuscript.

For ease of identification, filenames reflect their compositions and correspond to the alloy designations used in the publication as follows: • Co-101a (0.5 wt% C, 1 wt% Si) → C50Si1 • Co-101b (0.5 wt% C, 4 wt% Si) → C50Si4 • Co-101c (0.25 wt% C, 1 wt% Si) → C25Si1 • Co-101d (0.25 wt% C, 4 wt% Si) → C25Si4

The dataset includes scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs, elemental concentration maps acquired via energy-dispersive X-ray spectroscopy (EDX), electron backscatter diffraction (EBSD) maps, X-ray diffraction (XRD) data, mechanical testing results, digital image correlation (DIC) images, and thermal analysis data.