Numerical Simulation of 7A52 Aluminum Alloy Laser-MIG Hybrid Welding

Literature Overview

This study by Liu Ting et al., published in Precision Forming Engineering (Vol. 17, No. 6, 2025, pp. 150-159), presents a numerical simulation of laser-MIG hybrid welding of medium-thick 7A52 aluminum alloy plates. The research was supported by the National Natural Science Foundation of China (52205331), the Beijing Science and Technology Plan Key Project (KZ202210017023), and the National Natural Science Foundation Joint Fund Key Support Project (U22B20127). The authors employed Abaqus finite element software with a combined heat source model consisting of a conical heat source and a double-ellipsoidal heat source.

Core Technical Findings

The numerical simulation successfully captured the temperature field evolution, weld pool behavior, and material deformation during laser-MIG hybrid welding. The maximum simulated deformation of 1.72 mm compared favorably with the experimental value of approximately 2 mm, demonstrating good model accuracy. The simulated peak temperature reached 2050 degrees Celsius and the peak equivalent stress reached 301 MPa, providing quantitative insights into the thermal and mechanical conditions experienced by the material.

The combined heat source model was validated against experimental weld cross-section measurements, showing good agreement in weld geometry. This validation confirms the applicability of the selected heat source model for aluminum alloy laser-MIG hybrid welding simulation.

Simulation Parameters and Results

The simulation results reveal the coupling mechanism between temperature field, stress field, and material deformation. The optimized welding parameters obtained through simulation effectively suppress material deformation defects caused by non-uniform temperature distribution and residual stress concentration. This demonstrates the value of numerical simulation in process optimization prior to physical experimentation.

Engineering Practice Implications

For 7A52 aluminum alloy applications in aerospace and automotive industries, the numerical simulation approach provides a powerful tool for process optimization and defect prediction. The ability to predict deformation and residual stress distributions before physical welding enables proactive countermeasures such as fixture design, preheating strategies, and post-weld treatment planning. The combined heat source model, validated against experimental data, offers a reliable basis for predicting weld geometry and thermal cycles under various parameter combinations.

The simulation results also highlight the importance of considering the coupling between thermal and mechanical fields in hybrid welding processes. The peak equivalent stress of 301 MPa, while below the yield strength of 7A52 aluminum alloy, may contribute to residual stress accumulation and potential distortion in large-scale components. The optimized parameters identified through simulation can be directly applied to production welding, reducing trial-and-error costs and improving first-pass quality.

Study Insights and Reflections

The successful implementation of a combined heat source model for laser-MIG hybrid welding simulation represents a significant methodological contribution to the field. The good agreement between simulated and experimental deformation values validates the model's predictive capability. The study demonstrates that numerical simulation, when properly calibrated, can serve as a reliable tool for process development and optimization. The coupling analysis of temperature and stress fields provides deeper understanding of deformation mechanisms, enabling more targeted countermeasures for defect suppression.