Effect of [TiO.sub.2] nano-ceramic particles on microstructure and mechanical properties of [Al.sub.0.4][CoCrFe.sub.2][Ni.sub.2] high-entropy alloy

• Published in: China foundry Vol. 19; no. 6; p. 528
• Main Authors: Qi, Hao, Li, Guang-long, Zhang, Wei, Lu, Qing-yao, Li, Rong-de, Xie, Si-chen, Shi, Yu, Yu, Bo, Chen, Rui-run, Qu, Ying-dong
• Format: Journal Article
• Language: English
• Published: Foundry Journal Agency 01.11.2022
• Subjects: Alloys; Analysis; Crystals; Diffraction; Intermetallic compounds; Mechanical properties; Specialty metals industry; Structure; X-rays
• ISSN: 1672-6421; 2365-9459
• DOI: 10.1007/s41230-022-2124-9

[Al.sub.0.4][CoCrFe.sub.2][Ni.sub.2] high-entropy alloys with different additions of [TiO.sub.2] nanoceramic particles (0, 1.25vol.%, 2.5vol.%, 3.75vol.% and 5vol.%, respectively) were prepared by using the vacuum arc melting method. The effects of [TiO.sub.2] addition on the crystal structure, microstructures and mechanical properties of the alloy were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile testing. The microstructure analysis shows that the [TiO.sub.2] nano-ceramic particles added in the alloy are decomposed, and a small amount of [Al.sub.2][O.sub.3] and a great number of intermetallic compounds ([gamma]' phases) with simple cube structure are formed. The [gamma]' phases are enriched at inter-dendrite, which increases the resistance of dislocation movement during the deformation of the alloy, thus balancing the problem of high plasticity and low strength of the alloy. When the addition of [TiO.sub.2] is 2.5vol.%, the strength of the high-entropy alloy reaches the maximum of 489 MPa, which is 11.1% higher than the matrix alloy composed of single FCC phase. Keywords: high-entropy alloy; [TiO.sub.2] nano-ceramic particles; microstructure; mechanical property CLC numbers: TG146.21; Document code: A; Article ID: 1672-6421(2022)06-528-07