A Review of Laser Peening Methods for Single Crystal Ni-Based Superalloys
A Review of Laser Peening Methods for Single Crystal Ni-Based Superalloys
复制标题
单晶镍基高温合金激光强化方法综述
DOI：
10.3390/met12091414
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发表时间：
2022-08
期刊：
影响因子：
2.9
通讯作者：
Noah Holtham;K. Davami
中科院分区：
文献类型：
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作者：
Noah Holtham;K. Davami
单晶镍基高温合金因其在强热机械载荷下的高强度而常用于制造燃气涡轮机叶片。虽然它们在这些条件下具有显著的能力，但被称为表面引发损伤机制的特定类别的过早失效机制可能导致原本健康的叶片的早期断裂。本文讨论了后处理技术的最新进展，可以大大减轻表面引发的损伤机制的潜力。特别是，激光喷丸（LP）是显着的利益，由于相对较低的冷加工，它诱导，比其他冷加工方法，更大的深度的压缩残余应力，适应复杂的零件几何形状的能力，它对表面粗糙度的影响微乎其微。由LP施加的残余应力可以极大地阻碍裂纹生长，从而允许提高疲劳寿命。考虑到涡轮机叶片（由单晶镍基高温合金制成）容易因这些机制而失效，LP可能是延长其使用寿命的值得选择。出于这个原因，已采取主动，以更好地了解单晶镍基高温合金的LP赋予的机械和微观结构的修改和这些调查的总结在这篇评论。几项研究的结果表明，这类合金对LP处理反应良好，显微硬度提高约30-50%，低周疲劳寿命提高72%，耐热腐蚀性提高。本综述的主要目的是深入了解当前最先进的LP技术，并总结了许多利用LP提高单晶镍基高温合金部件使用寿命的研究结果。
Single crystal Ni-based superalloys are often used to create gas turbine engine blades for their high strength under intense thermo-mechanical loading. Though they are remarkably capable under these conditions, a particular class of premature failure mechanisms known as surface-initiated damage mechanisms can lead to the early fracture of an otherwise healthy blade. This review paper discusses the current progress of post-processing techniques that can greatly mitigate the potency of surface-initiated damage mechanisms. In particular, laser peening (LP) is of significant interest due to the relatively low amount of cold work it induces, greater depth of compressive residual stresses than other cold working methods, ability to accommodate complex part geometries, and the minuscule effect it has on surface roughness. The residual stresses imparted by LP can greatly hinder crack growth and consequently allow for enhanced fatigue life. Given that turbine blades (constructed with single crystal Ni-based superalloys) are prone to fail by these mechanisms, LP could be a worthy choice for increasing their service lives. For this reason, initiative has been taken to better understand the mechanical and microstructural modifications imparted by LP on single crystal Ni-based superalloys and a summary of these investigations are presented in this review. Results from several works show that this class of alloy responds well to LP treatment with improvements such as ~30–50% increase in microhardness, 72% increase in low cycle fatigue life, and elevated resistance to hot corrosion. The primary objective of this review is to provide insight into current state-of-the-art LP techniques and summarize the findings of numerous works which have utilized LP for increasing the service lives of single crystal Ni-based superalloy components.