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,1.6 mm;Al-50Si,0.8 mm;and Al-70Si,2 mm.Under this optimized scheme,the maximum deformation of the LTCC substrate when cooled to room temperature was found to be 4.86 μm,with the maximum first principal stress at 6.761 MPa—significantly below the LTCC material's fracture strength of 320 MPa.Similarly,the maximum deformation of the shell when cooled to room temperature was measured at 18.291 μm,and the maximum residual stress value was 20.46 MPa,substantially smaller than the yield strength of the shell material at 100 MPa.The stress concentration among the layers of the shell is not obvious,and the overall welding quality of the shell has been improved.
维普
万方数据