Influence of Boron on the Structure and Physicomechanical Properties of Ti30Zr25Hf15Nb20Ta10 High-Entropy Alloy

By the arc-melting method, we obtain a high-entropy boride by adding boron powder to the Ti30Zr25Hf15Nb20Ta10 alloy. The data of X-ray phase diffraction analysis show that the Ti30Zr25Hf15Nb20Ta10 alloy is a single-phase alloy with body-centered cubic (bcc) structure and that the main phase of the Ti15.8Zr13.4Hf7.8Nb10.5Ta5.3B47.2 alloy is MeB boride with insignificant amount of bcc and hexagonal close-packed structures. The microstructure of the obtained alloys is analyzed and it is shown that the addition of boron leads to the segregation of constituent components of the alloy. The addition of boron also increases the level of hardness from 3.5 to 33.5 GPa, the modulus of elasticity from 75 to 290 GPa, and the yield strength from 1.06 to 10.28%.