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对Ni_3Al(γ’)沉淀相尺寸对镍基单晶高温合金拉伸性能的影响进行了研究。对镍基单晶高温合金而言,材料的屈服来源于位错以Orowan机制绕过沉淀相,而Orowan应力与沉淀相间距有关。根据这一机理,基于晶体塑性理论,引入一个本构方程以表征沉淀相尺寸对镍基单晶高温合金屈服强度的影响。采用该本构模型,分别计算了在[001]以及[111]2个取向下,含有尺寸为0.2~2.5μm沉淀相的镍基单晶高温合金屈服强度,并与试验结果进行了对比验证。结果表明,该模型可以准确表征镍基单晶高温合金沉淀相的尺度效应。
The effect of Ni 3 Al (γ ’) precipitated phase size on the tensile properties of Ni-based single crystal superalloys was studied. For nickel base single crystal superalloys, the yielding of the material originates from dislocation bypassing the precipitated phase with the Orowan mechanism, whereas the Orowan stress is related to the spacing of precipitates. Based on this mechanism, a constitutive equation was introduced to characterize the influence of the precipitated phase size on the yield strength of a nickel-base single crystal superalloy based on the crystal plasticity theory. The constitutive model was used to calculate the yield strength of Ni - based single crystal superalloy containing 0.2 ~ 2.5μm precipitates with [001] and [111] orientations respectively. The results were compared with the experimental results. The results show that the model can accurately characterize the scale effect of the precipitated phase of Ni-based single crystal superalloy.