Effect of high-entropy alloy

[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.