搅拌摩擦辅助电弧增材制造热力耦合过程的数值模拟

Numerical Simulation on Thermomechanical Coupling Pro-cess in Friction Stir-Assisted Wire Arc Additive Manu-facturing

摘要:

电弧增材制造（WAAM）已成为大型构件成形制造的重要方法。但传统WAAM仍面临着如何改善材料微观组织、减少增材缺陷、降低工件残余应力和变形的问题，从而提升增材构件的力学性能。在WAAM过程中，进行层间搅拌摩擦处理可以调控构件的成形质量，但目前仍缺乏相关的热力耦合数值模拟研究。为此，建立了搅拌摩擦辅助WAAM热力耦合过程的数值模拟，定量分析了搅拌摩擦后处理对WAAM热力耦合过程的影响规律，分析了单层增材与多层增材过程中，搅拌摩擦处理对增材结构的残余应力与变形的影响规律。对WAAM和搅拌摩擦辅助WAAM不同沉积层的热过程进行分析。结果表明，进行后一层沉积会使已凝固的上一层发生局部重熔，而搅拌摩擦处理不会引起局部重熔。对增材构件进行热应力与变形分析，发现层间搅拌摩擦可以大大降低电弧增材构件的残余应力和翘曲变形，改善增材构件的性能。

Abstract:

Wire arc additive manufacturing (WAAM) has emerged as a promising approach for fabricating large-scale components. However, conventional WAAM still faces challenges in optimizing microstructural evolution, minimizing additive-induced defects, and alleviating residual stress and deformation, all of which are critical for enhancing the mechanical performance of the manufactured parts. Integrating interlayer friction stir processing (FSP) into WAAM significantly enhances the quality of deposited materials. However, numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient. A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM. The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively. Moreover, the residual stress distribution and deformation behavior under both single-layer and multi-layer deposition conditions were investigated. Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted. Results show that subsequent layer deposition induces partial remelting of the previously solidified layer, whereas FSP does not cause such remelting. Furthermore, thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components, thereby improving their structural integrity and mechanical properties.