Novel cast polycrystalline Ni3Al high-temperature alloy with excellent strength and preparation method thereof

The invention discloses a novel cast polycrystal Ni3Al high-temperature alloy with excellent strength, which comprises the following elements in atomic percent: 12-20% of Al; 6 to 12 percent of Cr; 1-3% of Mo; 0 to 3 percent of Ti; 0-3% of W; 0-2% of Ta; 0-4% of Fe; 0 to 0.6 percent of Zr; 0 to 0.4 percent of B; c: < = 0.1%; and the balance of Ni. The invention further discloses a preparation method of the novel cast polycrystalline Ni3Al high-temperature alloy with excellent strength. Elements such as Ta and Ti are added into the alloy, the alloy is promoted to further separate out a nanoscale gamma'phase, and the elements such as Ta and W play a solid solution strengthening role on the alloy, so that the strength of the alloy is greatly improved; the alloy has excellent strength, compared with an IC-221M alloy, the yield strength of the alloy is improved by 50% or above at the room temperature, the yield strength of the alloy is improved by 30% or above within the temperature range of 600-850 DEG C, and the