Preparation method of ultrafine grain nickel base powder high temperature alloy

Abstract

A preparation method of an ultrafine grain nickel base powder high temperature alloy belongs to the technical field of high temperature alloy. Pinning effect of crystal boundary gamma' particle during thermal deformation is utilized; powder high temperature alloy ingot is heated in air to a temperature 40-80 DEG C lower than a complete dissolving temperature of a gamma' hardening constituent thereof, treated with multiple heating quasi isothermal forging to reach a ingot accumulation deflection of higher than 75% and treated with recrystallization annealing to obtain a cake blank with uniform structure and grain size of grade 10-12. The invention has the following advantages: quasi isothermal forging with gross distortion of powder high temperature alloy can be realized to obtain ultrafine grain cake blank; production organization is simple and highly operational, so as to effectively solve a problem of processing powder high temperature alloy into uniform ultrafine grain by hot working; and produced cake blank has large deflection, so as to facilitate elimination of residual dendrite and original particle boundary in an isostatic pressing state tissue; product quality is good; production efficiency is high; and cost is low.

Description

technical field [0001] The invention belongs to the technical field of high-temperature alloys, and in particular provides a preparation method of superfine-grained nickel-based powder high-temperature alloys. Background technique [0002] Nickel-based powder superalloy is a new type of superalloy produced by powder metallurgy technology. It avoids the defects of high alloying degree, serious segregation, and poor thermal processing performance of conventional casting and forging superalloys. It has the characteristics of uniform structure and excellent comprehensive performance. Nickel-based powder superalloys mainly rely on the precipitation of γ′ (Ni 3 (Al, Ti, Nb)) phase is strengthened, usually the γ′ phase volume fraction is 30-65%, the degree of alloying is high, the deformation resistance is large, the hot working temperature range is narrow, the fluidity is poor during forging, and it is easy to crack. [0003] European and American powder superalloy ultra-fine cry...

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Problems solved by technology

Nickel-based powder superalloys mainly rely on the precipitation of γ′ (Ni 3 (Al, Ti, Nb)) phase is strengthened, usually the volume fraction of γ′ phase is 30-65%, the degree of alloying is high, the deformation resistance is large, the temperature range of hot working is narrow, the fluidity is poor and easy to crack during forging

[0003] European and American powder superalloy ultra-fine crystal cake blanks are mainly obtained by hot extrusion with a large powder extrusion ratio (3:1-9:1) to obtain densified fine-grained (grain size 10-12) blanks, and then vacuum or inert gas Superplastic isothermal forging under protection (strain rate less than 0.01s -1 ), this process route requires special large-scale equipment (large hot extrusion machine, vacuum or inert gas protection isothermal forging machine), complex process and high cost

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