Modeling and Control of Layer Height in Laser Wire Additive Manufacturing

Abstract

Laser Wire Additive Manufacturing (LWAM) is a flexible and fast manufacturing method used to produce variants of high metal geometric complexity. In this work, a physics-based model of the bead geometry including process parameters and material properties was developed for the LWAM process of large-scale products. The developed model aimed to include critical process parameters, material properties and thermal history to describe the relationship between the layer height with different process inputs (i.e., the power, the standoff distance, the temperature, the wire-feed rate, and the travel speed). Then, a Model Predictive Controller (MPC) was designed to keep the layer height trajectory constant taking into consideration the constraints faced in the LWAM technology. Experimental validation results were performed to check the accuracy of the proposed model and the results revealed that the developed model matches the experimental data. Finally, the designed MPC controller was able to track a predefined layer height reference signal by controlling the temperature input of the system.

Investigation and Optimization of the Impact of Printing Orientation on Mechanical Properties of Resin Sample in the Low-Force Stereolithography Additive Manufacturing

“…According to the fabrication process in the SLA [ 41 , 42 , 43 , 44 ], it can be seen that the fabricated resin sample consisted of large amounts of microparticles, which were controlled by the size of the laser spot and the thickness of each layer, and the force analysis for a single microparticle is shown in Figure 7 . The red block, yellow blocks, green blocks, and purple blocks represent the analyzed microparticle, the nearby microparticles within the line show the scanning direction, the nearby microparticles in the neighboring lines show feed direction, and the nearby microparticles in the adjacent layers show accumulation direction, respectively.…”

A Review on Wire-Laser Directed Energy Deposition: Parameter Control, Process Stability, and Future Research Paths

“…Therefore, it is commonly used in W-LDED to maintain process stability. Various controllers such as PI (Proportional-Integral), PLC (Programmable Logic Controller), MPC (Model Predictive Control), and ILC (Iterative Learning Control) have been utilized in research to implement closed-loop control strategies in W-LDED processes [128,135,174,213,222,223].…”

“…Mbodj et al designed a control system using an MPC controller capable of considering various material properties and process parameters. Using this system, the layer height was continuously monitored, and a constant height was maintained by controlling the temperature input [222].…”

The Grain Size Evolution Mechanism of A517Q Alloy Steel Fabricated by Laser and Wire Additive Manufacturing Assisted with Different Ultrasonic Vibration Treatments

“…[1][2][3][4] However, during the LWAM process, due to the complex thermal cycle experienced by the material, the microstructure of the sample is mainly composed of coarse columnar grains. [5][6][7][8] The coarse columnar grains will cause anisotropy and seriously affect the properties of materials. [9,10] Therefore, the grain refinement of deposited parts has become the focus of research in the LWAM field.…”