Influence of Metal Additives on Microstructure and Properties of Amorphous Metal–SiOC Composites

Strong, ductile, and irradiation-tolerant structural materials are in urgent demand for improving the safety and efficiency of advanced nuclear reactors. Amorphous ceramics could be promising candidates for high irradiation tolerance due to thermal stability and lack of crystal defects. However, they are very brittle due to plastic flow instability. Here, we realized enhanced plasticity of amorphous ceramics through compositional and microstructural engineering. Two metal–amorphous ceramic composites, Fe-SiOC and Cu-SiOC, were fabricated by magnetron sputtering. Iron atoms are preferred to form uniformly distributed nano-sized Fe-rich amorphous clusters, while copper atoms grow non-uniformly distributed nano-crystalline Cu particles. The Fe-SiOC composite exhibits high strength and plasticity associated with strain hardening, as well as a good thermal stability and irradiation tolerance. In contrast, the Cu-SiOC composite displays a very low plasticity and poor thermal stability. These findings suggest that the metal constituents play a crucial role in developing microstructure and determining properties of metal–amorphous composites.