Akademik Veri Yönetim Sistemi
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, ss.3412-3421, 2014 (SCI-Expanded)
The effect of Hf addition on microstructures, phase relationships, microhardness, and magnetic properties of Fe50Al50-n Hf (n) alloys for n = 1, 3, 5, 7, and 9 at. pct has been investigated. At all investigated compositions, the ternary intermetallic HfFe6Al6 tau (1) phase forms due to the limited solid solubility of Hf in FeAl phase and tends to develop a eutectic phase mixture with the Fe-Al-based phase. The Hf concentration of the eutectic composition is found to be 7 at. pct from the microstructural examinations and the eutectic phase transition temperature is determined as 1521 K (1248 A degrees C) independent of Hf amount by differential scanning calorimetry measurements. Furthermore, the enthalpies and activation energies (based on Kissinger and Ozawa methods) of eutectic phase transitions are reported. The minimum activation energy is calculated for the fully eutectic composition. Moreover, variation of the microhardness of Fe-Al-based alloys as a function of the Hf content is investigated, and its dependence on the thermal history of the alloys is explained. (C) The Minerals, Metals & Materials Society and ASM International 2014