A cryogenic electric pulse treatment method for removing residual stress of ultrafine-grained aluminum-lithium alloy strips

Abstract

A cryogenic electric pulse treatment method for ultra-fine-grained aluminum-lithium alloy thin strips to remove residual stress. The aluminum-lithium alloy thin strip coils are installed on the left side coiler, and the thin strips pass through guide rollers, cryogenic boxes, and conductive rollers in sequence. And connect the right side coiling machine, in which the conductive roller is placed in the cryogenic box; keep the temperature of the cryogenic box stably maintained at -60 ° C ~ -20 ° C; start the right side coiling machine, and slowly roll the aluminum-lithium alloy thin strip from the left side The crimping machine transitions to the right crimping machine; start the pulse power supply and apply pulse current to the conductive roller; increase the speed of the right crimping machine to a high speed, so that the residual stress of the aluminum-lithium alloy strip after the cryogenic pulse current treatment is fully released. The invention can eliminate the high residual stress in the ultra-fine-grained aluminum-lithium alloy without changing the grain size of the material, so that the aluminum-lithium alloy plate still has high strength after forming, but only has small springback.

Description

technical field [0001] The invention belongs to the technical field of metal material rolling, and in particular relates to a cryogenic electric pulse treatment method for removing residual stress of an ultrafine-grained aluminum-lithium alloy thin strip. Background technique [0002] Aluminum-lithium alloys are widely used in aerospace. In recent years, as the energy crisis and special application background have again promoted the development of lightweight aluminum alloys, it is eager to significantly reduce the weight of aircraft and maintain good overall performance. The addition of lithium can not only reduce the density of aluminum alloy, but also increase the modulus of elasticity, and can also make the alloy exhibit a strong aging strengthening effect. Compared with 2-series and 7-series aluminum alloys, the density of aluminum-lithium alloys can be reduced by 10%, while the specific stiffness can be increased by 25%, which has attracted widespread attention from e...

AI Technical Summary

Problems solved by technology

However, ultrafine-grained metal materials prepared by the macroplastic method have very high strength, however, the toughness is relatively low

The main reason is that the dislocation density of the material is relatively high, resulting in a relatively large residual stress of the material.

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