Al_2O_3-TiC/1Cr18Ni9Ti扩散焊接头应力分布

Stress distribution in Al_2O_3-TiC/1Cr18Ni9Ti diffusion bonded joint

用有限元方法计算了Al2O3-TiC/1Cr18Ni9Ti扩散焊接头的应力分布,研究了加热温度、压力和中间层对应力分布的影响。结果表明,残余轴向应力和剪切应力在试样边缘处梯度都较大,靠近中心轴,应力分布比较均匀,最大剪切应力出现在Al2O3-TiC/中间层界面处。在扩散焊冷却过程中,Al2O3-TiC/1Cr18Ni9Ti扩散焊接头最大轴向拉应力先是出现在边缘陶瓷侧,随着温度的降低,逐渐向试样中心靠近,应力值也逐渐增大。加热温度越低,轴向压应力越大。压力越大,最大轴向拉应力越小,压应力越大,但压力对剪切应力的影响较小。使用Ti-Cu-Ti复合中间层比使用Ti中间层可降低最大轴向压应力和最大剪切应力。

The stress distribution of Al2O3-TiC/1Cr18Ni9Ti diffusion bonded joint was calculated using the finite element method and the effects of bonding temperature,pressure and interlayer on the stress distribution were studied.The results indicate that the axial stress and the shear stress both change greatly near the sample edge,which uniform near the center.The greatest shear stress occurs at the Al2O3-TiC/interlayer interface.The greatest axial tensile stress shifts from the ceramic side on the sample edge to the steel side near the edge and the value increases with the temperature decreasing.The axial compressive stress increases when the bonding temperature reduces.The increasement of the pressure can reduce the maximal axial tensile stress and improve the compressive stress.The change of the pressure has little effect on the shear stress.Both of the axial tensile stress and the shear stress decrease with Ti-Cu-Ti interlayer compared with Ti interlayer.