Method for reducing residual tensile stress of additive manufacturing based on in-situ double-beam thermal field regulation

Abstract

This invention discloses a method for reducing residual tensile stress in additive manufacturing based on in-situ dual-beam thermal field modulation, relating to the field of metal additive manufacturing technology. The method includes: constructing a dual-beam scanning system; controlling the energy density parameter of the main beam through the dual-beam scanning system to irradiate a metal powder bed, causing the metal powder to completely melt and form a molten pool, thus completing the formation of the current processing layer; controlling an auxiliary beam after the main beam through the dual-beam scanning system to perform in-situ heat treatment on the solidified area; and forming a local compressive stress field in the solidified area through the heat input of the auxiliary beam to counteract the tensile stress generated by solidification shrinkage, thereby reconstructing the thermal stress field. This invention achieves active reconstruction of the thermal stress field without introducing secondary melting or adding subsequent heat treatment processes, avoiding secondary deformation of thin-walled structures or precision parts with complex internal flow channels caused by post-processing stress release.

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