光学学报, 2017, 37 (4): 0414004, 网络出版: 2017-04-10
激光喷丸强化IN718合金晶粒重排与疲劳特性
Grain Rearrangement and Fatigue Property of IN718 Alloy Strengthened by Laser Peening
激光技术 晶粒重排 激光喷丸 IN718合金 疲劳 残余应力 laser technology grain rearrangement laser peening IN718 alloy fatigue residual stress
摘要
为了揭示激光喷丸(LP)强化IN718合金疲劳寿命增益的机制,研究了合金喷丸前后晶粒重排与疲劳特性的关系。结果表明,LP后试样表层的塑性形变深度最大可达33.7 μm,合金的最大疲劳寿命增益可达188%;激光冲击波诱导产生的表层残余压应力随激光功率密度的增大而增大,但增幅逐渐减小; 疲劳试验后,表层残余应力出现了52%的释放;LP后试样表层晶粒出现细化现象,细化深度达到175 μm; 位错滑移和位错攀移以及孪晶等共同作用使原始晶粒内形成了亚晶粒,最终细化了晶粒组织。
Abstract
In order to clarify the mechanism of fatigue life enhancement of IN718 alloy strengthened by laser peening (LP), the relationship between the grain rearrangement and fatigue property of the alloy before and after LP is studied. The results show that, after LP, the maximum plastic deforming depth of sample surface reaches 33.7 μm, and the maximum fatigue life enhancement of the alloy reaches 188%. With the increase of laser power density, the surface residual compressive stress induced by laser shock wave increases, but the amplification decreases gradually. After the fatigue test, the release of the surface residual stress of 52% appears. The grain refinement phenomenon is found on the sample surface after LP, and the refining depth reaches 175 μm. The interaction among the dislocation sliding, dislocation climbing and twin crystal results in the generation of subgrains, and eventually the grain structure is refined.
黄舒, 盛杰, 谭文胜, 王作伟, 孟宪凯, 刘牧熙, 杨小乐. 激光喷丸强化IN718合金晶粒重排与疲劳特性[J]. 光学学报, 2017, 37(4): 0414004. Huang Shu, Sheng Jie, Tan Wensheng, Wang Zuowei, Meng Xiankai, Liu Muxi, Yang Xiaole. Grain Rearrangement and Fatigue Property of IN718 Alloy Strengthened by Laser Peening[J]. Acta Optica Sinica, 2017, 37(4): 0414004.