Quantifying the residual stress at micron-scale is crucial for comprehending the trans- and inter-granular deformation mechanisms and the influence of heat treatment, but remains technically challenging. This study utilized focused ion beam and digital image correlation (FIB-DIC) techniques to assess residual stress within the dendrite stem and arm of nickel-based single-crystal superalloys. The influence of hot isostatic pressing (HIP) on the microstructure and residual stress was also elucidated. Our results revealed that the residual stresses in the dendrite stem and arm regions manifest as tensile stress along the x-axis and compressive stress along the y-axis, with a range of -720 MPa to 680 MPa. HIP treatment effectively improved microstructure and regulated residual stress in nickel-based single-crystal superalloys, leading to a rapid reduction in residual stress levels. The present study lays a solid theoretical groundwork for optimizing processing strategies to regulate residual stress and enhance mechanical properties in next-generation single-crystal superalloys.

中文翻译：

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热等静压对镍基单晶高温合金微米级残余应力的影响


在微米尺度上量化残余应力对于理解跨晶粒和晶间变形机制以及热处理的影响至关重要，但在技术上仍然具有挑战性。本研究利用聚焦离子束和数字图像相关 （FIB-DIC） 技术来评估镍基单晶高温合金的枝晶茎和臂内的残余应力。还阐明了热等静压 （HIP） 对微观结构和残余应力的影响。结果表明，枝晶茎和枝臂区域的残余应力表现为沿 x 轴的拉应力和沿 y 轴的压应力，范围为 -720 MPa 至 680 MPa。HIP 处理有效地改善了镍基单晶高温合金的微观组织并调节了残余应力，从而迅速降低了残余应力水平。本研究为优化加工策略以调节残余应力和提高下一代单晶高温合金的机械性能奠定了坚实的理论基础。