Mechanism for superior fatigue performance of warm laser shock peened IN718 superalloy after high-temperature ageing
Mechanism for superior fatigue performance of warm laser shock peened IN718 superalloy after high-temperature ageing
复制标题
温激光冲击喷丸IN718高温合金高温时效后优异疲劳性能的机制
DOI：
10.1016/j.jallcom.2022.166340
复制
发表时间：
2022-07
影响因子：
6.2
通讯作者：
Xiu Song
中科院分区：
文献类型：
--
作者：
Yang Liu;Lei Wang;Kaiyue Yang;Xiu Song
研究了热激光冲击处理（WLSP）后的IN718合金在室温和600℃高温时效后的高周疲劳性能。阐明了WLSP对IN718合金硬化表层的强化增韧机理，揭示了WLSP在高温下具有高度稳定的强化效果。结果表明，在高温长期使用过程中，与传统的激光冲击强化相比，热辅助表面硬化技术在保持硬化层合金的抗疲劳性能和延长疲劳寿命方面具有更明显的优势。经WLSP处理后，在硬化面层中形成了γ″相/高密度位错（SFs）的复杂结构和γ″相的纳米孪晶，并被更稳定、密度更高的几何必需位错（GNDs）所包围。因此，硬化面层由于产生更稳定的异质变形诱导应力（HDI）而取得了显著的强化效果。同时，由于特殊组织的存在，高温时效过程中WLSP合金硬化层的亚结构演化、残余压应力降低和γ″相生长也受到抑制，有利于高温时效及后续高温循环加载条件下组织的稳定性和强化效果。从而提高了WLSP合金在试样表面的抗疲劳起裂性能和起裂时间。这是高温时效后WLSP试样在室温和600℃下均能保持稳定的抗疲劳性能并提高中值疲劳强度的主要原因。
The high cycle fatigue properties of IN718 alloy treated by warm laser shock processing (WLSP) were studied after high-temperature ageing at both room temperature and 600 ℃. The strengthening and toughening mechanism of WLSP on the hardened surface layer of IN718 alloy was elucidated to reveal the highly stable strengthening effects at high temperature. It was found that the thermally assisted surface hardening techniques had more obvious advantages in maintaining fatigue resistance and prolonging fatigue life of the alloy with the hardened surface layer during long-term service at elevated temperature, comparing with the conventional laser shock peening (LSP). After WLSP treatment, complex structures of γ″ phase/high-density dislocation with stacking faults (SFs) and nano-sized twins in γ″ phases surrounded by the more stable and higher density of geometrically necessary dislocations (GNDs), formed in the hardened surface layer. Therefore, a remarkable strengthening effect in the hardened surface layer was achieved due to the production of more stable hetero-deformation induced (HDI) stress. Meanwhile, the substructure evolution, compressive residual stress reduction and γ″ phase growth in the hardened layer of WLSP alloy were also inhibited during high-temperature ageing, owing to the existence of the special structure, contributing stability of microstructure and strengthening effect under conditions of high-temperature ageing and subsequent cyclic loading at high temperature. Thus, both the fatigue crack initiation resistance and initiation time of WLSP alloy can be improved in the surface of specimen. This is the main reason why after high-temperature ageing the fatigue resistance of WLSP sample can be kept stably and the median fatigue strength can be improved at both room temperature and 600 ℃.
登录
查看更多内容
影响因子：
9.8
作者：
N. Prastiti;Yilun Xu;D. Balint;F. Dunne
通讯作者：
N. Prastiti;Yilun Xu;D. Balint;F. Dunne
δ 相对室温镍基高温合金疲劳裂纹扩展行为的作用
DOI：
10.1016/j.msea.2016.12.029
发表时间：
2017-01
期刊：
Materials Science and Engineering A
影响因子：
--
作者：
Jinlan An;Lei Wang;Yang Liu;Wenliang Cai;Xiu Song
通讯作者：
Xiu Song
影响因子：
4.7
作者：
H. Lee;Hyunmyung Kim;Donghoon Kim;C. Jang
通讯作者：
H. Lee;Hyunmyung Kim;Donghoon Kim;C. Jang
影响因子：
6.2
作者：
Hongyu Yi;Jiheng Li;Haijun Yu;Fan Li;X. Bao;Xuexu Gao
通讯作者：
Hongyu Yi;Jiheng Li;Haijun Yu;Fan Li;X. Bao;Xuexu Gao
影响因子：
2.7
作者：
Rui-Ning Yuan
通讯作者：
Rui-Ning Yuan