Microstructures evolution and physical properties of laser induced NbC modified nanocrystalline composites

- Ultrafine nanocrystals, quasicrystals, amorphous were produced in such laser clad hard composites.
- Portion of amorphous was resolved into nanoscale particles included in icosahedral quasicrystals.
- A portion of the amorphous phases could be resolved into icosahedral quasicrystals.
- Ultrafine nanocrystals can also intertwin with amorphous, forming yarn-shape materials.

The nanoscale quasicrystals (NQs), amorphous and ultrafine nanocrystals (UNs) modified hard composites are produced by laser cladding (LC) of the Ni60A-TiC-NbC-Sb mixed powders on the additive manufacturing (AM) TA1 titanium alloy. The LC technique is favorable to formations of icosahedral quasicrystals (I-phase) with five-fold symmetry due to its rapid cooling and solidification characteristics. The formation mechanism of this I-phase is explained here. Under the actions of NQs, amorphous and UNs, such LC composites exhibited an extremely high micro-hardness. UNs may also intertwin with amorphous, forming yarn-shape materials. This research provides essential theoretical basis to improve the quality of laser-treated composites.