NbMoTaW high-entropy alloy, and preparation method thereof

The invention belongs to the technical field of high-entropy alloy, and discloses a NbMoTaW high-entropy alloy, and a preparation method thereof. According to the preparation method, mechanical alloying and spark plasma sintering are combined for forming, alloying of Nb, Mo, Ta, and W which are high in melting points is realized at solid states, heating to the melting points is not necessary, block materials with excellent performance can be obtained via only one time of solid phase sintering ( the sintering temperature is 1600 DEG C or lower), a difficult problem that the melting temperature (>2900 DEG C) of smelting method is high is solved, processing temperature is reduced greatly, and technology is simplified. According to the microscopic structure of the NbMoTaW high-entropy alloy, dispersion distribution of a granular second phase in an isometric crystal substrate is observed, both the substrate phase and the second phase are BCC solid solution, the substrate average particle size is smaller than 6 m, the second phase average particle size is smaller than 4 m, the material crystal particles are small, the structure is uniform, no dendritic segregation is caused, and strength and hardness are high.