In-situ spherical TiB2/Cu composite powder: A new method of liquid phase reaction coupled with gas atomization

The spherical TiB2/Cu composite powder was fabricated by a new method of liquid-phase in-situ reaction coupled with inert gas atomization. The powder morphology, characteristic indexes, microstructure and nano-indentation hardness were investigated. The effects of spheroidization time and solidification rate of atomized molten droplets on powder sphericity and the relationship between in-situ reaction control and TiB2 distribution were discussed. Results indicate that the powder has a good sphericity and d(50) is 32.86 mu m, in addition to 75% fine powder yield (<45 mu m). The in-situ formed TiB2 particles (TiB2p) were uniformly distributed in grain boundaries and intragrain. The rapid solidification of molten droplets and the inhibition of copper grain growth by TiB2p refined the Cu matrix grain size (4.34 mu m). The nanoindentation hardness of composite powder is 3.17 GPa, which is 1.9 times higher than that of spherical Cu powder, and the reasons for the increased hardness of powder are also discussed.

Automated summary

The study focuses on the fabrication of spherical TiB2/Cu composite powder using a new method of liquid-phase in-situ reaction coupled with inert gas atomization. The results show that the powder has good sphericity and enhanced nano-indentation hardness due to the uniform distribution of in-situ formed TiB2 particles in the matrix.