Titanium and zirconium powders did not yield nitrides effectively by the treatment in pressurized ammonia of 1 MPa and above, at 700°C for 3 h. The addition of NH₄Cl was effective for the nitridation of Ti and Zr. Reactions of titanium powder (99.1 % up) mixed with 10 wt% (9.2 mol%) ammonium chloride have been studied at 300-700°C under 0.1 or 1 MPa NH₃ (initial pressure) for 3 h. Ti and NH₄CI did not react at 300°C, but formed TiH_1.924 at 400°C, and then TiH_1.924 changed into TiN above 500°C. When the sample of Ti-10 wt% NH₄Cl was heated at 300-600°C under 0.4 MPa Ar gas for 3 h, TiH_1.924 was produced at 400°C and above, but TiN was not produced.
When the sample of Zr-10 mol% (6 wt%) NH₄Cl was heated under 0.1 or 1 MPa NH₃, ZrN was formed above 600°C through the formation of ZrH and ZrH₂ above 400°C. A small amount of β-ZrNCI was also produced at 700°C under the same conditions.