Finite Element Analysis Of The Layered Structure Materials Of Si(C,N)/Stainless Stell

The big difference in properties between ceramics and metals can lead to very highresidual stress in ceramics after brazing. Study on distribution and value of the residualstress in ceramics/metal, find the method to reduce the residual stress is an importantproblem of bonding ceramics and metals．The thermal-elastic-plastic finite element method was used to study the value anddistribution of different kinds of the residual stress in the layered structure materials ofSi(C,N)/Ag-Cu-Ti/1Cr18Ni9Ti. Meanwhile, the effects of brazing temperature, pressure,stress reduction interlayers, such as Cu foil, Ni foil, Ti foil, Mo foil and differentthickness of stress reduction interlayers on residual stress of the layered structure materialswere simulated.Si(C,N) ceramic and1Cr18Ni9Ti were brazed using Ag-Cu-Ti active filleralloy to get the layered structure materials, Then the residual stress was measured by littlehole method and validate the numerical simulation with experimental results.The results of numerical simulation showed that, the maximal normal residual stresswere mainly concentrated in the edge of Si(C,N) near the interface, the maximal interfacialresidual stress were concentrated in the surface of interface while the maximal shearingstress concentrated in the interface. With the change of the brazing temperature andpressure, the distribution of residual stress stay the same, only the value changes. The peakof residual stress was the lowest with the brazing temperature of1000℃, pressure of10MPa. The residual stress was modified when using anyone of Cu foil, Ni foil, Ti foil, Mofoil as stress reduction interlayer. Stress reduction interlayer with lower yield stress (Cu、Ni、Ti) relieve the residual stress in ceramics rely on its’ plastic strain. The lower yieldstress means the lower residual stress.The distribution of residual stress was changed bystress reduction interlayer with lower CTE(such as Mo). With the thickness of interlayerbecome larger, residual stress decreases first and increases later. The best thickness ofinterlayer of Cu foil, Ni foil, Ti foil, Mo foil were0.4mm. The simulation results wasconsistent with the experimental results.