Nonlinear Dynamic Contact Analysis For Research On The Process Of Silver-based Filler Metal By Powder Electromagnetic Compaction

Cadmium-free silver-based intermediate temperature filler metals have excellentwetting and spreading performance, good electrical conductivity, thermal conductivityand corrosion resistance, and can get the excellent mechanical properties of brazedjoints and have better forming performance. So they have broad application prospectsin the field of microelectronic packaging, automotive, aerospace, military and otherindustries. The traditional preparation methods of silver-based are multi-pass rollingafter melting and molten or rapid solidification in the molten state. The traditionalmethod of the process is complex and low yield. Electromagnetic forming is a newway to prepare cadmium-free silver-base intermediate filler metals by combined withthe powder metallurgy and electromagnetic forming, to avoid the drawback of thetraditional process and reduce the brittle phase with high yield.However, this method refers to several physical fields, there are so manyparameters in the compaction process; only with the method of experiment to get theinfluence of each parameter on sample’s properties is not economical. To solve thisproblem, this article use the finite element analysis software ANSYS and Marc tosimulate the three physical fields of circuit, electromagnetism and structure in theprocess of electromagnetic compaction on powder; with the systemically analysis ofeach part to detect the influence of each parameter on the compaction results.This paper analyzes not only the respective effect of each single factors ofwinding’s circle number, capacitance and voltage on the electromagnetic force, butalso the influence of current and voltage under the condition of the fixed dischargeenergy and different technological conditions of drive thickness, the gap betweendrive and the coil on the electromagnetic force.For the powder compacting process of silver-base filler metal, this paper hasmade some simulation for the Ag45Cu27Zn25Sn Cadmium-free silver-baseintermediate temperate filler metal powder compacting process on the direction ofElastic-plastic mechanics model and Shima yield criterion, by using the nonlineardynamic contact analysis method, on the basis of relationship of the powdercompact’s elasticity modulus and density ratio ensured by The Brazilian discexperiment. All the results were corresponded with the experimental results, whichvalidated the correction of computer simulation. Through a lot of simulation calculation, we analyzes the effect of different process conditions of voltage,capacitance, punch quality, clearance distance between punch and powder, die bottomrigidity and the way of filling process to the green forming quality and efficiency; andrevealed the influence rule of these process conditions on the filler metal powderelectromagnetic forming.Many technological conditions studied in this article were not concerned in thepast research of electromagnetic forming process, and some of them are applicable tothe other indirect electromagnetic forming research beyond electromagneticcompaction. The conclusions of the paper have a great help to optimize theparameters of electromagnetic forming, meanwhile, it has certain significance toexpand and deepen for powder electromagnetic forming theory.