Phase transformation in oil-quenched Ni–21.2Al–20Fe alloy

• Published in: Journal of alloys and compounds Vol. 509; no. 5; pp. 1644 - 1647
• Main Authors: Zhou, Z.C., Gu, S.Y., Wen, C.E.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 03.02.2011; Elsevier
• Subjects: Anelasticity, internal friction, stress relaxation, and mechanical resonances; Condensed matter: structure, mechanical and thermal properties; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cooling; Cooling curves; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Heating; Intermetallic compounds; Internal friction; Martensitic transformations; Materials science; Mechanical and acoustical properties of condensed matter; Nickel aluminides; Nickel base alloys; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase transformation; Physics; The oil-quenched Ni–21.2Al–20Fealloy; Phase transformation; Internal friction; The oil-quenched Ni–21.2Al–20Fealloy; Differential scanning calorimetry; Cooling; Phase transformations; Forced vibration; The oil-quenched Ni-21.2Al-20Fealloy; Martensitic transformations; XRD; Martensitic structure; Heat treatments; Reverse martensitic transformations; Experimental design; First order reversal curve diagram
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2010.11.096

▶ In this study, the phase transformation characteristics of the quenched Ni–Al–Fe alloys have been described by internal friction measurements and DSC experiments. ▶ The effects of Fe addition on the phase transformation and internal friction behavior of Ni–Al-based alloys were investigated and discussed. ▶ The internal friction peak during heating is originated from the L1 0 → γ transformation. ▶ The adding of Fe has influences on the peak temperature and height. The internal friction ( Q −1) and the relative dynamic modulus (RDM) of the oil-quenched Ni–21.2Al–20Fe alloy were measured using a multifunctional internal friction apparatus by forced-vibration methods from room temperature to 200 °C. An internal friction peak is represented on the internal friction-temperature curve at about 113 °C during heating and the peak is shifted to about 38 °C during cooling for the oil-quenched alloy. The peak temperature does not change for different vibration frequencies during both heating and cooling, and therefore the peak is non-relaxational. It has been shown that the peak-heights decrease with increasing f and decreasing heating rate ( T ˙ ) and are linearly and directly proportional to T ˙ / f . DSC measurements show that there is an endothermal peak at 107 °C and an exothermal peak at 42 °C on the heating curve and cooling curve, respectively. Both temperature values are similar to those of the internal friction measurements during heating and cooling, respectively. XRD results show that the oil-quenched Ni–21.2Al–20Fe alloy possesses martensitic structures (L1 0) in addition to Ni 3Al and Ni 5Al 3. It can be deduced that the internal friction peak during heating is resulted from reverse martensitic transformation of L1 0 → γ and originated from martensitic transformation of γ → L1 0 during subsequent cooling. The internal friction peak height increases when Fe content is raised.