Formation of titanium nitride by mechanical milling and isothermal annealing of titanium and boron nitride

Structural evolution of hexagonal BN and cubic BN during ball milling

“…The grain size of c-BN was kept in the range of 26-33 nm during ball milling, revealing that c-BN grains have not obviously refined due to its super-hardness. All the h-BN diffraction peaks, except the weak (0 0 2) peak, disappeared when the sample was milled for 24 h. Eventually the (0 0 2) peak of h-BN nearly disappeared after milling for 48 h. This phenomenon is similar to those happening in other systems during ball milling, such as Al-BN [8], Ti-BN [9], Fe-BN [10] and others. At the same time, except from the diffraction peaks of h-BN and c-BN, a diffuse peak appeared at the lower diffraction angle side of h-BN (0 0 2) during the disappearing of the h-BN (0 0 2) peak.…”

“…It has also been widely reported that the X-ray diffraction (XRD) peaks of one component disappeared quickly in the early stage of ball milling in many binary systems, especially in the systems containing a hexagonal crystalline component, such as Al-BN [8], Ti-BN [9], Fe-BN [10], Ti-C [11], W-MoS 2 [12] and W-C in our previous work. So far this phenomenon has been generally interpreted as crystallite refinement, formation of solid solution, amorphization.…”

Characterization of structure and properties of TiN–TiB2 nano-composite prepared by ball milling and high pressure heat treatment

“…1(e), consisted of a-BN and δ-TiN x peaks, which indicated that Ti have been completely reacted with N and formed δ-TiN x . It is deduced that N atoms from a-BN gradually diffuse into Ti lattice and form amorphous Ti-N alloy, then it crystallized to δ-TiN x in ball milling process [10]. And these result in that the remaining a-BN became B-rich amorphous BN, which was confirmed by DSC measurement.…”

“…2 showed DSC curves of amorphous-BN produced by ball milling h-BN. The crystallization temperature of the a-BN at atmospheric pressure was about 630 • C, but above 900 • C for the B-rich amorphous BN [10]. This identified that the remained a-BN is not a-BN but a B-rich amorphous BN.…”

Raman scattering investigation of nanocrystalline δ-TiNx synthesized by solid-state reaction

“…Generally, the main factors that are responsible for the shift of the Raman spectra are composition, grain size, defects, and internal stress in the sample powder. As discussed in ours another article [9], N atoms in the a-BN incorporate into nanocrystalline Ti with a large amount of defects induced during milling process to form amorphous Ti N alloy. When the phase diagram of N Ti is considered, the solubility of N in Ti at room temperature is very low, and when N content in amorphous alloy exceeds some critical value, which should be above 30 at.% [10], amorphous Ti N crystallizes to δ-TiN x driven by the local temperature and local pressure [11].…”