缓冲层对Si(C,N)/不锈钢合金层状结构残余应力的影响

Influence of stress reduction interlayer on residual stress of Si(C,N) and stainless steel alloy layer structure

陶瓷与金属直接连接后在陶瓷侧会产生很大的残余应力。采用热弹塑性有限元方法,模拟计算Cu,Ni,Ti,Mo等缓冲层及缓冲层的不同厚度对复合材料残余应力的影响。Cu,Ni,Ti,Mo缓冲层均能缓解复合材料内的残余应力,屈服强度低的Cu,Ni,Ti依靠自身的塑性变形,能有效降低陶瓷部分的残余应力。缓冲层的屈服强度越低,缓解残余应力的作用越明显。线膨胀系数小的Mo可以调整残余应力场的分布状态。随着缓冲层厚度的增加,残余应力先减小后增大,Cu,Ni,Ti,Mo缓冲层的最佳厚度为0.4 mm。

High residual stress was produced at ceramic side after ceramic and metal connected directly. The thermal-elas- tic-plastic finite element method was used to simulate and calculate the influence of stress reduction interlayer, such as Cu, Ni, Ti, Mo and different thickness of stress reduction interlayer on composite residual stress. Cu, Ni, Ti, Mo stress reduc- tion interlayer can relieve residual stress of composite material, lower yield strength such as Cu, Ni, Ti relying on its own plastic strain can relieve the residual stress of ceramics effectively. The lower yield strength, the more obvious relieve effect on residual stress. The low linear expansion coefficient Mo can change distribution state of residual stress. With the thick- ness of interlayer become larger, residual stress decreases first and then increases. The best thickness of stress reduction in- terlayer of Cu, Ni, Ti, Mo is 0.4 mm.