Novel treatment method for nano precipitation strengthened CoCrNi-based high-entropy alloy

Abstract

The invention discloses a novel treatment method for a nano precipitation strengthened CoCrNi-based high-entropy alloy, and relates to the technical field of high-entropy alloys. The novel treatment method comprises the following steps that after an as-cast CoCrNi-based high-entropy alloy is subjected to homogenizing annealing for 1.5-3 h at the temperature being 1150-1250 DEG C, first-time machining deformation thinning is conducted till the thickness is 30-60% of that of the as-cast alloy, then recrystallization treatment is conducted for 8-15 min at the temperature being 1150-1250 DEG C, second-time machining deformation thinning is conducted till the thickness is 70-85% of that of the alloy subjected to first-time machining deformation, then aging treatment is conducted for 12-20 h at the temperature being 650-850 DEG C, and the strengthened CoCrNi-based high-entropy alloy is obtained. The room temperature rolling process is adopted twice in the mechanical heat treatment process of the CoCrNi-based high-entropy alloy, compared with an existing process, the strengthening effect is remarkable, the yield strength is improved by 400 MPa or above, and the maximum tensile strength is improved by 300 MPa or above.

Description

technical field [0001] The invention relates to the technical field of high-entropy alloys, in particular to a treatment method for a novel nano-precipitation strengthened CoCrNi-based high-entropy alloy. Background technique [0002] In recent years, high-entropy alloys have received extensive attention due to their excellent properties, especially face-centered cubic (FCC) high-entropy alloys with near-equal atomic ratio composition. These alloys have excellent plasticity, high damage tolerance, and good Corrosion resistance and radiation resistance. However, the low strength of high-entropy alloys as FCC substrates hinders their widespread application. Among the high-entropy alloys in the FCC matrix, CoCrNi-based high-entropy alloys have attracted many scholars' research because of their good toughness and good phase stability. CoCrNi-based high-entropy alloys also have the disadvantage of low strength of FCC matrix alloys. Therefore, how to improve the strength of CoCr...

AI Technical Summary

Problems solved by technology

The process is complicated and economical, and it is difficult to get out of the laboratory and enter industrialization, which greatly limits the application of high-performance high-entropy alloys; there are also some nano-precipitation-strengthened CoCrNi-based high-entropy alloys prepared by conventional processes that are not superior in strength and performance. The main process is: the as-cast alloy ingot is homogenized at 1250°C for 4 hours, then rolled at room temperature to reduce the thickness by 80%, recrystallized at 1200°C for 10 minutes, and finally aged at 700°C for 20 hours

The process adopts conventional methods, the process is simple, and the economy is good, but the improvement of the performance of the alloy is limited.

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