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研究980℃,200MPa拉伸蠕变期间[001]和[011]取向镍基单晶合金中γ′相的形貌演化及蠕变特征,在相同拉伸条件下晶体取向的变化对合金的应变和应变速率产生明显影响。结果表明:沉淀相的定向粗化方向取决于合金的晶体取向,沿[001]取向拉伸,γ′相从最初的立方形态转化为与拉伸应力轴垂直的筏形;当拉伸轴平行于[011]取向时,γ′相沿[010]和[100]方向扩散生长,演化成与拉伸轴倾斜45o角的筏形。[011]取向合金的蠕变强度随其基体通道宽度的增大而快速下降,蠕变前期[001]与[011]取向的应变速率相近,蠕变后期合金表现出明显的蠕变各向异性。
The morphological evolution and creep characteristics of γ ’phase in [001] and [011] orientated nickel-base single crystal alloys during 980 ℃ and 200MPa tensile creep tests were investigated. The effect of crystal orientation changes on the strain of the alloy And strain rate have a significant impact. The results show that the directional coarsening direction of the precipitated phase depends on the crystal orientation of the alloy and is oriented in [001] orientation. The γ ’phase transforms from the initial cubic shape into a raft shape perpendicular to the tensile stress axis. When the stretching axis is parallel In the [011] orientation, the γ ’phase grows diffusely in the [010] and [100] directions and evolves into a raft with a 45 ° angle to the axis of extension. The creep strength of the oriented alloy decreases rapidly with the increase of the width of the matrix. The strain rates of the [001] and [011] orientations in the early creep phase are similar, and the creep late phase alloys show obvious creep anisotropy .