Microstructure and properties of TiAl-4822 alloy subject to the solid-state treatment with pulsed magnetic field

• Published in: Materials characterization Vol. 211; p. 113919
• Main Authors: Li, G.R., Zhao, B.W., Wang, H.M., Ji, Z.J., Ding, X.F., Nan, H., Zhang, J.J., Wu, T.T., Chen, S.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.05.2024
• Subjects: Dislocations; Magnetic field treatment; Mechanical properties; TiAl alloy; Mechanical properties; Magnetic field treatment; TiAl alloy; Dislocations
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2024.113919

The limited plasticity of γ-TiAl-based alloys presents a significant challenge in their application for aerospace components. In this study, the as-cast TiAl-4822 (Ti-48Al-2Nb-2Cr) alloy was subjected to magnetic field treatment at varying levels of magnetic induction intensity. The pulsed magnetic field induces magnetic stress and thermal effects on the microstructure of grains and dislocations, resulting in an increased lamellar spacing, reduced lamellar thickness, equiaxed γ precipitation, abundant grain boundaries, a high dislocation density, finer grains, and prominent orientation characteristics. The changes in microstructure and properties of 1 T and 2 T specimens are not readily discernible; however, a significant grain refinement is observed in the case of 3 T and 4 T specimens. Additionally, there is an increase in dislocation density evident, accompanied by an enhancement in lamellar structure as well as the emergence of equiaxial γ-TiAl phase. The elongation and tensile strength of the optimized 4 T specimens have simultaneously increased by 31.3% and 11.57%, resulting in values of 0.84% and 261.61 MPa, respectively, compared to those of the untreated alloy. •The problem of low room temperature elongation in the TiAl-4822 alloy was effectively addressed through solid-state treatment.•The correlation between the microstructure and mechanical properties of the treated samples was investigated.•The application of pulsed magnetic field solid state treatment can effectively enhance the microstructure of the alloy while maintaining its original shape.•The mechanical properties significantly improve after magnetic field treatment, with a 31.30% increase in elongation and an 11.57% increase in tensile strength observed at a magnetic induction intensity of 4 T.•The enhancement of room temperature elongation can effectively enhance the safety index of aircraft engine blades.