Eutectic Brazing Process And Simulation Of 6061 Aluminum Alloy And Kovar Alloy

Active phased array radar?APAR?is a phased array radar that is developed with the rapid development of microwave phase shifting technology,circuit technology,computer technology and numerical simulation technology.At present,in the assembly of high-density transceiver components for active phased array antennas,there are problems such as reliability and consistency of eutectic soldering of connectors and housings,which are difficult points in the design and manufacture of high-density transceiver components,and their defects are formed.The influence mechanism,regularity and brazing process optimization methods need to be studied.In this paper,AnSn/SnPb two kinds of solder eutectic welding 6061 aluminum alloy/4J34 Kovar alloy was studied.The influence of brazing process on weld morphology,phase and residual stress was studied,and the residual stress simulation and experimental study were studied.Optimize the appropriate brazing process parameters.The main research and results of the paper are as follows:?1?When the surface of the 6061 aluminum alloy is heated to 295°C,the AnSn solder will melt instantaneously and rapidly solidify and shrink to produce wrinkles;at310°C and 325°C,the AnSn solder melts instantaneously but does not immediately undergo solidification shrinkage.The Sn in the AnSn solder rapidly reacts with Au in the gold plating layer of the base material to form an Au₅Sn???intermetallic compound,and the base material forms a dense metallurgical bond through the intermetallic compound.?2?When the surface of the 6061 aluminum alloy is heated to 190°C,the SnPb solder melts and spreads well;the SnPb solder will diffuse as the temperature increases,and the higher the temperature,the more severe the flow phenomenon.The SnPb solder reacts with the gold plating layer on the base material to form AuPb₃ and Au₅Sn???phases,forming a brazed joint with good metallurgical bonding.?3?The residual stress simulation of the finite element model of the welded joint weld is carried out.The residual stress value of the side weld of the 6061 aluminum alloy side weld-solder layer-kovar alloy is“V”shape distribution,and its calculated value and X The trend of the ray residual stress test measurement is completely consistent.The calculated and measured results show that the residual stress near the Kovar side weld is higher.?4?The numerical simulation is used to calculate the residual stress value of AnSn solder at different soldering temperatures for 60s.The results show that at the same welding temperature,the residual stress at the side weld of the aluminum alloy increases slightly with the increase of the welding heat preservation time;the residual residual stress of the joint is the lowest at 310°C;the weld of the SnPb solder weld sample The simulation results of residual stress show that different welding temperatures and welding holding time have little effect on the numerical results.The measured results of X-ray residual stress are in good agreement with the calculated values,which proves the correctness of the simulation results.