Numerical Simulation On Deformation Of Ag-Cu Solder Made By Electromagnetic Compaction And Experimental Verification

As demand for silver based solder increasing in all walks,the silver based solder always becomes one of hot spots as a good filler metal in the field of brazing,and with the rapid development of filling technology,it has already become one of most wildly use solders.Electromagnetic compaction provides new ideals and methods for preparation of silver based solders with excellent performance,which makes solder composition formula emerge in endless.These years,the rapid development of computer simulation technologies has brought great convenience to the results prediction of tests,which has one of the core method in various researches.And the method of combining the electromagnetic compaction and the computer simulation technology becomes a new hot spot in solder compaction field.Now,the theoretical foundation of most powder compaction is the Finite Element Theory.The developing finite element theory is a good way to explain some powder compaction simulation so far,but the Discrete Element Theory proposed in 70 s conforms to actual simulation.The Discrete Element Theory could give out more accurately predictions about powders' mechanical performances in compaction process.However,there is few studies on silver based solders compaction with the theoretical foundation of discrete element theory.Therefore,it would have a guiding significance to study the silver based compaction process by used of the discrete element theory.The main content of this particle was simulating the silver based solder compaction and analyzed results of simulations by using the discrete element theory.The simulations and analyses of silver powder in high speed,binary silver based solder compaction in high speed and low speed and ternary silver based solder in high speed were provided in this particle.And This paper has also compared the results of simulation with the experiment's.The results of simulation experiments showed that: It was feasible to describe the densification process of silver based solder by using the discrete element theory.According to the discrete element theory,the overlap between solder particlecharacterized the deformation of particles,which was increasing with the increasing of the processing force.Whether the high speed compaction or low speed compaction,the voidage of silver base solder decreased linearly but slower and more and more slow when it was blow the 10%.The voidage of middle powders was lower than both the top and the bottom.The average compaction force was the main factor in influencing densification of silver based solders.The voidage was negative related the average compaction force.The total compressive force increased as the compaction process going on and the maximum value of force increase with the processing speed of compaction.So did the average compressive force.The growth of compressive was as faster as time went on,which was also influenced by stiffness coefficient.That the force needed time to spread form the top of the particles to the bottom made different particles with different speed and the change of speed in the middle was the most.The minimum error between simulation and experiment is 8%.The total numbers of contacts was increasing as the time went on.And the time for particles relative sliding would be longer with the increased species.The single number of contacts was affected by its total number.The more the particle were the more the number of contacts were,which meant that the more deformation of the whole solder.