Laser shock processing effects on isothermal oxidation resistance of GH586 superalloy
Laser shock processing effects on isothermal oxidation resistance of GH586 superalloy
复制标题
激光冲击加工对GH586高温合金抗等温氧化性能的影响
DOI：
10.1016/j.apsusc.2015.01.033
复制
发表时间：
2015-03-01
影响因子：
6.7
通讯作者：
Liu, Haixia
中科院分区：
文献类型：
--
作者：
Hua, Yinqun;Rong, Zhen;Liu, Haixia
氧化是镍基合金高温失效的主要形式之一，激光冲击强化不仅可以提高镍基合金的力学性能，而且可以提高其抗氧化性能。因此，研究激光冲击处理对该合金抗氧化性能的影响是十分必要的。研究了激光冲击处理对GH586高温合金显微组织、显微硬度和等温氧化性能的影响。采用扫描电子显微镜、能谱仪、透射电子显微镜和X射线衍射技术分析了氧化膜的微观结构变化和表面形貌。此外，还测量了LSP处理样品的显微硬度。结果表明，与未处理的试样相比，LSP试样表面上的平均晶粒尺寸显著更细（33.3 μ m对18.5 μ m）。已经观察到高度缠结和密集的位错排列以及大量的孪晶。氧化后，样品中的缺陷密度（位错和孪晶）降低。在800 ℃和900 ℃下，氧化动力学近似遵循抛物线氧化规律.氧化层主要由Cr2O3、NiCr2O4、TiO2和Al2O3组成，在初始氧化过程中，激光冲击处理的表面氧化层生成较快。激光冲击处理后，由于氧化层致密、细小、均匀，平均氧化速率较低。结果表明，激光冲击处理后的试样具有较好的抗高温氧化性能。(C)2015爱思唯尔B.V.保留所有权利。
The oxidation is one of the main failure mode of Ni-based alloy at high temperature, laser shock processing not only can improve the mechanical properties but also the oxidation resistance. So the study on laser shock processing effects on oxidation resistance of this alloy is necessary. The aim of this paper is to investigate the effects of laser shock processing on microstructure, micro-hardness and isothermal oxidation resistance of GH586 superalloy. Scanning electron microscopy, energy-dispersive spectrum, transmission electron microscope, and X-ray diffraction technique were used to analyze the microstructure changes and the surface morphologies of the oxide scales. In addition, micro-hardness of LSP-treated samples was measured. The results show that the average grains size on the surfaces of LSP specimen was found to be significantly finer compared to the untreated one (33.3 pm vs. 18.5 mu m). Highly tangled and dense dislocation arrangements and a high amount of twins have been observed. After the oxidation, the defects density (dislocations and twins) in the specimen decreased. The oxidation kinetics approximately followed a parabolic oxidation law at 800 degrees C and 900 degrees C. The oxidation layer was composed of Cr2O3, NiCr2O4, TiO2, and Al2O3, which generated more quickly on the surface treated by LSP during initial oxidation. The average oxidation rate was lower after LSP due to the dense, tiny and homogeneous oxidation layer. The results show that the specimens treated by LSP have a better high temperature oxidation resistance. (C) 2015 Elsevier B.V. All rights reserved.