Characteristics of microstructure evolution of surface treated IN718 superalloy by warm laser shock peening during long-term aging at high temperatures
Characteristics of microstructure evolution of surface treated IN718 superalloy by warm laser shock peening during long-term aging at high temperatures
复制标题
IN718高温合金温激光冲击喷丸表面长期时效组织演变特征
DOI：
10.1016/j.matchar.2022.112261
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发表时间：
2022-11-01
影响因子：
4.7
通讯作者：
Song，Xiu
中科院分区：
文献类型：
--
作者：
Liu，Yang;Wang，Lei;Song，Xiu
研究了IN 718高温合金经激光冲击强化（LSP）和温激光冲击强化（WLSP）处理后在600 ~ 680 °C高温长期时效过程中的组织演变行为及其机理。结果表明，与激光冲击处理相比，激光冲击处理可有效抑制高温下硬化层的亚结构演化行为、残余压应力降低和γ″相粗化。由于WLSP合金硬化层中形成了γ″相、γ″相中存在层错和微孪晶的高密度位错的复杂结构，在γ″相周围产生了更稳定、更高密度的几何必需位错，改变了硬化层的微观应力分布，产生了更稳定的异向变形强化效应。研究结果为进一步深化WLSP处理IN 718高温合金表面硬化层的强韧化微观机理提供了新的认识，促进了WLSP技术在高温合金关键零部件制造领域的更实际应用。
The microstructure evolution behavior and its mechanism of the surface treated IN718 superalloy by laser shocking peening (LSP) and warm laser shocking peening (WLSP) followed by long-term aging at high temperature ranging from 600 °C to 680 °C were investigated in the present study. It was found that the substructure evolution behavior, compressive residual stress reduction and γ″ phase coarsening of the hardened surface layer of WLSP sample could be effectively inhibited at high temperature, in comparison with those of LSP counterpart. Owing to the formation of complex structure of γ″ phase and high-density dislocation with stacking faults (SFs) and micro-twins in γ″ phase in the hardened layer of WLSP alloy, more stable and higher density geometrically necessary dislocations (GNDs) were developed around γ″ phase, which changed the micro-stress distribution of the hardened layer and produced more stable hetero-deformation induced strengthening effects. The findings of the present study provide a new cognition for further deepening the micro-mechanism of strengthening and toughening of hardened surface layer in WLSP treated IN718 superalloy at high temperature, promoting the more practical application of WLSP technology in the manufacturing field of key components of superalloys.