Study On Preparation Technology Of Multiple Alloy Of Alumina Ceramic Brazing For Vehicle

Ceramics as a kind of specificity of non-metal materials with low density,high hardness,high temperature resistant,corrosion resistant,strong insulation characteristics,connection of ceramic and metal ceramic-metal composite material,can be combined with the advantage of the two materials,complement each other,make its in lightweight car body,improve the vehicle performance has a great application prospect.Currently,ceramic and metal of the widely used silver based solder,by soldering process,but there are technology is complex,high silver brazing alloy content,the problem of high cost,and low silver content solder brittle compound,and contains a lot of hard processing molding,this restricted the promotion and application of ceramic-metal composite materials.In order to solve the problem that the brittle low silver alloy solder is difficult to be machined and formed,an innovative method is proposed to prepare the solder alloy powder by powder metallurgy and then process the solder alloy foil by cold pressing.By means of DTA differential thermal analysis,brazing test,brazing test in furnace,shear and tensile test of joint,SEM and EDS analysis of weld microstructure,it is verified that the solder alloy foil prepared by this process has good brazing performance.The main contents of this paper are as follows:(1)Design of low Ag alloy solder systemThe brazing alloy powder with good brazing performance was prepared by gas atomization method.On this basis,multiple metal powders were added to the alloy powder to form multi-particle composite filler metal,which improved the compressibility and formability of the filler metal powder.(2)low silver alloy solder formingBy optimizing the ratio of particle size and composition and improving the pressing parameters,the properties of the composite filler metal with multiple particles were further optimized,and the pressed blank of powder with high density and high strength was obtained by cold pressing once.(3)Analysis of experimental results of brazing properties of solderThe addition of single powder can improve the spreading performance of composite solder,but increase the melting distance.The mechanical test results show that the welding fractures are all on the ceramic,indicating that the weld joints are reliable.It was observed by SEM that the weld was mainly composed of ?-Cu solid solution,?-Ag solid solution and a small amount of Cu and Sn intermetallic compounds.This study explores a new way for the forming process of brittle solder and is expected to promote the further development and application of powder metallurgy process in automobile parts connection.