Laser three-dimensional forming closed-loop simulation method

Abstract

The invention discloses a laser three-dimensional forming closed-loop simulation method. The simulation method is different from a common thermal coupling model. The constant laser power is simply adopted in the whole simulation process; the laser power of the next molten pool is continuously and dynamically adjusted based on the technological characteristics of laser three-dimensional forming, and compared with an existing laser three-dimensional forming thermal coupling model, the finite element optimization modeling method based on temperature closed-loop control better conforms to the objective law of the actual forming process. The optimization model more suitable for the real machining process can inevitably and more accurately reveal the thermal-force field evolution law and the coupling mechanism thereof, and a scientific criterion is provided for relieving laser three-dimensional forming stress and deformation.

Description

【Technical field】 [0001] The invention belongs to the field of additive manufacturing, and in particular relates to a closed-loop simulation method for laser stereoforming. 【Background technique】 [0002] Additive manufacturing technology is an advanced manufacturing technology that uses point-by-point accumulation to manufacture parts. Its core idea is "discrete-accumulation", which is different from machining (subtractive manufacturing) and casting / forging (equal material manufacturing). This technology can realize rapid free forming without mold, has the characteristics of fast manufacturing speed, near-net shape, and is suitable for single-piece and small-batch manufacturing. It is widely used in aerospace, medical, mold, automobile, engineering and other fields. The metal additive manufacturing process is a complex metallurgical process involving moving molten pool, solidification, and solid-state phase transition. It has the characteristics of nonlinear, unsteady, mult...

AI Technical Summary

Problems solved by technology

However, in the actual forming process, the change of the temperature field of the molten pool is affected by many factors such as the scanning path, boundary conditions, and the shape of the part. This type of control method does not consider the influence of these key factors on the temperature stability of the molten pool. Effective monitoring and control of the time and even the temperature of the molten pool, including the poor real-time performance of the control system, which eventually leads to large error in the results

In addition, response hysteresis, poor real-time control effect, etc. may lead to closed-loop control divergence

Hinders process control, ideal closed-loop control of melt pool temperature is currently lacking

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