2219铝合金搅拌摩擦焊缝装配质量的响应曲面法建模及分析

Modeling and Analysis of Assembly Quality of AA2219 Friction Stir Welding by Response Surface Methodology

焊缝间隙、焊缝错缝量以及搅拌针与焊缝中心的对中情况(简称焊缝对中)等三项条件作为焊缝装配质量的构成要素,对铝合金搅拌摩擦焊焊缝接头的性能有较为明显的影响。针对航天焊接结构件中常用的2219铝合金,为了能综合反映焊缝装配质量对搅拌摩擦焊缝接头性能的综合影响,利用响应面法建立了焊缝装配质量三要素与焊缝接头强度及延伸率之间的数学模型,分析了焊缝间隙、焊缝错缝量及焊缝对中对焊缝接头性能的影响情况。通过实验发现,焊缝间隙依然是影响焊缝接头性能的关键因素,而焊缝错缝量及焊缝对中会使焊缝接头性能表现出非对称性。该方法为焊缝装配质量的量化描述提供了数学模型,并且利用响应面法所获得的数学模型,可以为制定合理的焊缝装配条件提供指导依据,避免了传统针对单个装配要素进行研究的弊端,并且具有良好的工程应用前景。

Gap,misalignment and non-centering of probe (NCOP for abbreviation)are three important elements of the assembly quality of friction stir welding joints.Actually,these three elements have combining effects on the joint performance.In this paper,aiming at AA221 that is commonly used material in aerospace welding structures,the mathematic model between these three elements and the weld joint performances is established by the response surface methodology.The influence of each element on the weld joint is analyzed.Through experiments,the gap is found to be the key element on the weld joint performance,and the amount of misalignment and NCOP will cause the weld joint performance to show asymmetry.This method provides a mathematical model for the quantitative description of weld assembly quality.And,the mathematic model is used to provide reasonable instruction for these three elements of assemble quality of weld joints.This method avoids the disadvantages of traditional way on individual assembly elements and has good engineering application prospects.