|Microstructural evolution of nanostructured Ti0.9Al0.1N prepared by reactive ball-milling Original Research Article |
U.K. Bhaskar, S. Bid, S.K. Pradhan
▶ Nanocrystalline stoichiometric Ti0.9Al0.1N powder has been prepared by ball-milling the 0.9 mol fraction of α-Ti (hcp) and 0.1 mol fraction of aluminum (fcc) powders under N2 at room temperature. Initially, α-Ti phase partially transformed to the transient β-Ti phase and Ti0.9Al0.1N (fcc) phase is noticed to form after 3 h of milling. Nanocrystalline stoichiometric Ti0.9Al0.1N phase is formed after 7 h of milling. The main features which are observed in the present study are stated below:
1. During ball-milling of α-Ti, the α-Ti phase partially converted to transient cubic β-Ti phase within 1 h of milling.
2. Ti0.9Al0.1N (fcc) phase is noticed to form after 3 h of milling. Complete formation of Ti0.9Al0.1N (fcc) is obtained at 7 h of milling which is lesser than complete formation time (9 h) of TiN. Doping Al atoms accelerates the formation of (TiAl)N phase.
3. The particle size of Ti0.9Al0.1N decrease rapidly up to 3 h and then increase slightly due to agglomeration effect.
4. The particle size of Ti0.9Al0.1N estimated from X-ray is in good agreement with that measured from HRTEM.