Nitride‐Reinforced Metal Matrix Nanocomposite Powders Production by Plasma‐Assisted Thermochemical Treatment of Intermetallic Powders

This work presents a novel method for producing metal matrix nanocomposite powders using an in situ precipitation technique. As a proof‐of‐concept, TiN nanoparticles are synthesized directly on the surface of FeTi intermetallic powder particles (d ₉₀ < 8.0 μm) through plasma‐assisted nitriding treatment. An equipment is specially designed to enable the movement of powder particles under a controlled 33%H ₂ + 67%N ₂ atmosphere in a rotating drum anode placed around a hollow‐cathode discharge producing the nitrogen reactive species. Plasma operating parameters are fixed at −650 V (cathode potential) and 1.5 Torr (gas pressure), and the treatments are carried out at 550 °C for 4 h. Treated particles’ surface analysis indicated the formation of TiN spherical nanoparticles distributed all over the particle. In addition to the TiN phase, the diffractograms showed the formation of the α‐Fe (ferrite). The presence of N in the samples, as well as the chemical bond between Ti and N, is measured by X‐ray photoelectron spectroscopy (XPS) analysis. The results demonstrated the feasibility of producing nitride‐reinforced nanocomposite powders through an in situ technique using a new plasma‐assisted nitriding process for metallic powders. This approach opens up a huge field for the development of other metallic matrix nanocomposites.