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对镍基单晶合金材料DD3的[001]取向试样进行950℃、278 MPa/250 MPa两种载荷水平的3个时间阶段的单轴拉伸蠕变试验。采用扫描电镜(SEM)观察各试验阶段试样的γ/γ’两相微观组织。通过抽样统计得到基体相γ通道水平宽度在三个蠕变时间阶段的概率密度函数,其概率分布服从对数正态分布。分析了在同一温度下两种载荷水平对γ相水平宽度变化的影响,并结合蠕变寿命曲线分析了微观γ相水平宽度与蠕变时间的函数关系。结果表明,外加载荷是影响基体相γ通道水平宽度增长速率的重要因素,但对在蠕变断裂后最终的γ相宽度值的影响不显著。
The uniaxial tensile creep tests of [001] oriented samples of nickel-based single crystal alloy DD3 at three time stages of 950 ℃, 278 MPa / 250 MPa were carried out. Scanning electron microscopy (SEM) was used to observe the γ / γ ’two-phase microstructure of the specimens in each experimental stage. The probability density function of the horizontal phase width of the phase γ in the three creep time stages is obtained by sampling statistics. The probability distribution obeys the logarithmic normal distribution. The effects of two load levels on the variation of γ-phase horizontal width at the same temperature were analyzed. The function of the horizontal width of γ phase and the creep time was analyzed based on the creep life curve. The results show that the applied load is an important factor that affects the growth rate of the horizontal γ phase of the matrix. However, the influence on the final γ phase width after creep rupture is insignificant.