FORMATION AND HARDENING EFFECTS IN NANOCRYSTALLINE TI-N ALLOYS PREPARED BY MECHANICAL ALLOYING

Nanocrystalline Ti-N alloys have been prepared by mechanical alloying in a controlled milling atmosphere. X-ray diffraction, differential scanning calorimetry and microhardness measurements were used to investigate the formation, structure,phase transformation, thermal and mechanical properties of nanocrystalline Ti-N alloys. The relationship among solute content, grain size and microhardness has been studied. The reaction between Ti(N) solid solution and TiN may occur at a relatively low temperature, indicating that the as-formed nanocrystalline Ti-N alloys are metastable and in a high energy state. Strong solid solution hardening has been observed for both the as-milled and the annealed nanocrystalline Ti-N alloys.