Method for testing laser metal direct forming based on self-healing mechanism

Abstract

The invention discloses a method for testing laser metal direct forming based on self-healing mechanism, which is to carry out laser single-path metal forming tests under the conditions of different powder defocusing amounts respectively by adopting the same basic process parameter so as to obtain a variation law of the section thickness of single-path metal forming under the conditions of different powder defocusing amounts. The self-healing mechanism existing under the condition of powder negative defocusing by analyzing the law, can automatically eliminate a phenomenon of a rough forming surface caused by unstable process in a forming process along with performance of forming, thereby ensuring stable performance of the forming process. By applying the self-healing effect generated by powder negative defocusing, high-quality deposition forming of a complicated thin-walled component can be realized under an open-loop control system.

Description

technical field [0001] The invention relates to a method applicable to laser metal direct forming manufacturing, laser surface cladding and laser repair of vulnerable parts, and in particular to an experimental method of laser metal direct forming based on a self-healing mechanism. Background technique [0002] Laser metal direct forming technology combines rapid prototyping technology and laser cladding technology, based on the principle of "discrete-stack" forming. First, the 3D model of the final functional part is generated in the computer; then the 3D data information of the part is converted into a series of 2D contour geometric information, and the layer geometric information is fused with the forming parameters to generate the NC code of the scanning path. The control forming system adopts synchronous feeding laser melting The overlay method scans the stacked material layer by layer according to the contour trajectory; finally forms a three-dimensional solid part or ...

AI Technical Summary

Problems solved by technology

However, due to the complex forming process conditions, the shape of the molten pool is affected by many factors such as the physical and chemical properties of the base material and powder alloy, and the laser forming process parameters. As the laser forming height increases layer by layer, unevenness will occur on the forming surface. has a cumulative effect

Under the open-loop control system, after multi-layer accumulation, it will be unable to continue to accumulate due to severe jaggedness due to uneven accumulation

Adjusting the process parameters (changing the Z-axis increment) can solve this problem, but at the same time introduces new problems such as the unpredictability of the height of the formed parts; the introduction of closed-loop control can effectively solve this problem, but it increases the complexity of the system and increases cost, inconvenient to operate

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