摘要
采用热弹塑性有限元方法,在考虑了材料性能参数随温度变化和界面反应层的情况下,计算了陶瓷/金属钎焊接头残余应力的大小和分布。通过计算发现:陶瓷/金属接头在冷却过程中产生的径向应力和剪应力对接头的影响较小,而在陶瓷表面的边缘接近焊缝的位置产生了最大的轴向拉应力,它影响接头的载荷承受能力,并且由于40Cr的屈服强度比45钢的高,计算出的Si_3N_4/40Cr接头的应力峰值比Si_3N_4/45钢的高。陶瓷/钎料和陶瓷/金属的界面反应层虽然薄,但它也是影响陶瓷/金属接头残余应力大小和分布的一个重要因素。另外,选择合适的钎料层、中间层和钎焊压力都可以有效地减小残余应力的峰值。
The residual stress in ceramics/metal joints was calculated by thermal-elastic-plastic finite element method. The influence of temperature on the material properties and the interface reaction layer was taken into account. The radial stress and shearing stress had a little influence on the joints, but a peak axial tensile stress which influenced on load-bearing capacity of joints occurred at the ceramic surfaces on the edges. The maximum of residual stress of Si3N4/40Cr brazed joints is higher than that of Si3N4/45 steel joints, because yield strength of 40Cr steel is higher than that of 45 steel. Though the reaction layers of interfaces are thin, they are important factors which influence on residual stress. In addition, the peak residual stress can be reduced by appropriate filler metal, interlayer and brazing pressure.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2003年第5期33-36,41,共5页
Transactions of The China Welding Institution
基金
高等学校重点实验室访问学者基金
国家自然科学基金(50275001)
关键词
陶瓷-金属
钎焊
残余应力
数值分析
热弹塑性有限元
焊接接头
Bearing capacity
Ceramic materials
Elastoplasticity
Finite element method
Numerical analysis
Residual stresses
Tensile stress
