梯度硅铝管壳回流焊接快速冷却热力仿真研究  

Thermal simulation of rapid cooling for reflow welding of gradient Si-Al shell

作　　者：李胜伟 冯晓晶 彭鑫[2] 孙鹏 王凯[1] LI Shengwei;FENG Xiaojing;PENG Xin;SUN Peng;WANG Kai(Xi’an University of Technology,Xi’an 710048,China;China Academy of Space Technology(Xi’an),Xi’an 710000,China)

机构地区：[1]西安理工大学,西安710048 [2]中国空间技术研究院西安分院,西安710000

出　　处：《空间电子技术》2024年第1期39-45,共7页Space Electronic Technology

基　　金：国家研发课题(编号:2022-JCJQ-LB-006)。

摘　　要：针对某航天电子管壳焊接组件冷却过程中的热力耦合影响问题,建立了焊接组件的有限元热分析模型,研究了在快速冷却过程中梯度材料分布对低温共烧陶瓷(low temperature co-fired ceramic,LTCC)基板、梯度管壳的残余应力和变形的影响。以不超过基板断裂强度为前提条件,以降低管壳整体的残余应力与变形为优化目标,采用了多因素变换优选法,确定了管壳材料的最优梯度分布方案,即合金管壳自上而下的梯度分布为Al-35Si、Al-42Si、Al-50Si、Al-60Si、Al-70Si。其中,Al-35Si厚度为2.5mm,Al-42Si与Al-60Si的厚度均为1.6mm,Al-50Si厚度为0.8mm,Al-70Si厚度为2mm。在该方案下,LTCC基板冷却至室温时的最大变形量为4.86μm,最大第一主应力为6761MPa,远小于LTCC材料的断裂强度320MPa;管壳冷却至室温时的最大变形量为18.291μm,最大残余应力值为20.46MPa,远小于管壳材料的屈服强度100MPa。管壳各层之间的应力集中现象不明显,管壳的整体焊接质量得到提升。A finite element thermal analysis model was established to solve the problem of thermal coupling during the cooling process of an aerospace electronic tube shell welding component.The effect of gradient material distribution on the residual stress and deformation of Low Temperature Co-fired Ceramic(LTCC)substrate and gradient shell during rapid cooling has been investigated.Ensuring that the substrate’s fracture strength is not exceeded and with the optimization goal of reducing the residual stress and deformation of the entire shell,a multifactor transformation preference method was employed to determine the optimal gradient distribution scheme for the shell material.Specifically,the gradient distribution of the alloy shell from top to bottom was set as Al-35Si,Al-42Si,Al-50Si,Al-60Si,and Al-70Si.The thicknesses of the layers were defined as follows:Al-35Si and Al-60Si,2.5mm;Al-42Si and Al-60Si,1.6mm;Al-50Si,0.8mm;and Al-70Si,2mm.Under this optimized scheme,the maximum deformation of the LTCC substrate when cooled to room temperature was found to be 4.86μm,with the maximum first principal stress at 6.761MPa—significantly below the LTCC material’s fracture strength of 320MPa.Similarly,the maximum deformation of the shell when cooled to room temperature was measured at 18.291μm,and the maximum residual stress value was 20.46MPa,substantially smaller than the yield strength of the shell material at 100MPa.The stress concentration among the layers of the shell is not obvious,and the overall welding quality of the shell has been improved.

关 键 词：回流焊 梯度硅铝管壳 基板 多因素变换优选法 

分 类 号：V45[一般工业技术—材料科学与工程]