Effect of local pressure on the crystallization product of amorphous alloys induced by mechanical milling

Mechanism of formation of Fe–N alloy in the solid-state reaction process between iron and boron nitride

“…2(a), the peaks of ε-Fe x N in Fig. 2(b) shift towards higher diffraction angles, indicating a decrease of the N content in the ε-Fe x N [5]. When the 60 h-milled mixture was annealed for 1 h at 1170 K under atmosphere pressure, ε-Fe x N decomposed to ␣-Fe and ␥-Fe(N), as shown in Fig.…”

“…This implies that there exists an amorphous alloy in the 25 h-milled mixture. The XRD measurement results of the 25 h-milled mixture showed that after the DSC run the sample was composed of ␣-Fe, ␥ -Fe 4 N and a-BN [5]. This indicated that Fe reacted with a-BN to form an Fe-N amorphous alloy after milling of 25 h and that ␥ -Fe 4 N was formed by crystallization of the amorphous Fe-N alloy.…”

“…In this milling process Fe reacts with the N atoms of the h-BN to form ε-Fe x N alloys [5]. However, no Fe-B alloy was obtained during all experiments.…”

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

“…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]. With extending milling time, N atoms continue dissolve into nanocrystalline Ti to form amorphous Ti N alloy; on the other hand, N atoms also incorporate into amorphous Ti N and δ-TiN x , leading to increment of N content of δ-TiN x .…”

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

“…The local temperature is higher than the crystallization temperature of the amorphous Ti-N alloy, 375 • C, while the local pressure can promote crystallization of the amorphous alloy in a polymorphous crystallization mode. Therefore, when the N content in the amorphous alloy exceeds some critical value, which should be above 30 at.% [9], the amorphous Ti-N crystallizes to ␦-TiN x driven by the local temperature and local pressure [10]. With extended milling time, on the one hand, the N atoms continue to dissolve into the nanocrystalline Ti to form amorphous Ti-N alloy.…”