带热沉装置的搅拌摩擦焊研究

Research on FSW process with thermal sink apparatus

基于动态控制低应力无变形焊接法原理和搅拌摩擦焊特有的应力应变特点,设计开发了可应用于搅拌摩擦焊的单点式热沉和阵列式射流冲击热沉系统。通过两种不同热沉系统在铝合金搅拌摩擦焊中的对比研究,结果表明,单点式热沉虽然可以减小FSW焊接变形,但此种冷却方式会使接头性能大幅度下降,接头强度仅达到常规FSW的80%左右。经过改进的阵列式射流冲击热沉系统可以主动控制FSW过程中各个区域的温度分布,从而有效控制焊接过程的热弱塑性应力应变场,达到动态控制低应力无变形的焊接效果。焊缝氢含量的测试分析表明,阵列式射流冲击热沉系统可以改善接头的残余应力分布,防止冷却水侵入焊缝。带阵列式射流冲击热沉系统的搅拌摩擦焊技术可以实现低应力无变形焊接,且工艺适用性好,具有广阔的应用前景。

Based on the Dynamical Control-Low Stress No Distortion（DC-LSND） welding method and the characteristic of residual stress and residual strain in convention FSW process,two thermal sink apparatuses were designed and apllied for FSW process.Contrasted the performnace of single jet sink apparatus and array jet impingement sink apparatus,it is indicated that using the single jet sink apparatus can control the distortion in FSW process,but the mechanical properties of joints drop dramatically,it can only be 80% of the conventional FSW joints.The new array jet impingement sink apparatus can control the distribution of temperature field actively, therefor it can control the distribution of residual stress and residual strain fields effectively.Hence, achieve the effect of low stress no distortion welding.The hydrogen contents investigations show that the FSW process with array jet impingement sink appaatus can prevent the joints form the effect of colding water.The FSW adopted with array jet impingement heat sink is economic ,fine serviceable and promising for FSW application.