蠕变空洞尺寸对镍基高温合金应力场的影响规律

Effect of creep cavity size on stress field of nickel-based alloy

为研究在热等静压作用下蠕变空洞大小对镍基高温合金应力场分布的影响,采用有限元方法分别计算了不同尺寸蠕变空洞附近的应力场分布情况。结果表明,空洞顶点距离γ'相中心越近,镍基高温合金中最大von Mises应力和最高弹性应变能密度越小;当蠕变空洞的顶点到γ'相中心距离相同时,在垂直方向上,基体垂直通道上von Mises应力和弹性应变能密度从上到下递增,基体水平通道上递减。而且随着蠕变空洞半径增大,合金中基体通道上的von Mises应力和弹性应变能密度递增和递减的趋势越明显。

In order to investigate the influence of creep cavity size on stress field of nickel-based superalloys under the application of hot isostatic pressing,the finite element method（FEM） was adopted to calculate the stress distribution in the vicinity of creep cavities with various sizes.The results show that the maximum von Mises stress and the elastic strain energy density become smaller when the top of the cavity gets closer to the center of the γ＇ phase.When the distances from the top of creep cavities to the center of the γ＇ phase are equal,the von Mises stress and the elastic energy density of the vertical matrix channels increase in the vertical direction from top to bottom,while those of the horizontal matrix channels decrease.With the increase of the radius of creep cavities,the variation of the von Mises stress and elastic strain energy density of the matrix channel in the alloy becomes more evident.