Hua Yang, Liu Zhanqiang, Yi Jie, Tang Aijun
School of Mechanical and Electronic Engineering, Shandong Jianzhu University, Jinan 250101, China.
Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China.
Materials (Basel). 2022 May 24;15(11):3740. doi: 10.3390/ma15113740.
Mechanical surface treatments are needed to perform on components for fatigue life enhancement by introducing beneficial compressive residual stress and material strengthening. In this study, the combined turning with low plasticity burnishing (LPB) surface modification process was performed for the sake of improving mechanical properties of Inconel 718. Firstly, the evolution of microstructure and residual stress after the LPB process were analyzed with the aid of electron backscatter diffraction (EBSD) and X-ray diffraction (XRD), respectively. Secondly, the tensile behavior of treated samples was investigated through tension tests. Finally, the micro-strengthening mechanism of Inconel 718, induced by the LPB process, was revealed. The results show that the peak compressive stress is increased by a factor of 4.2 after the LPB process. The grain refinement induced by the LPB process is attributed to the increase of average misorientation and the formation of high angle grain boundaries (HAGBs). The enhanced yield strength depends on the decreased average spacing and the increased HAGBs.
需要对部件进行机械表面处理，通过引入有益的压缩残余应力和材料强化来提高疲劳寿命。在本研究中，为了改善Inconel 718的力学性能，进行了车削与低塑性研磨（LPB）表面改性相结合的工艺。首先，分别借助电子背散射衍射（EBSD）和X射线衍射（XRD）分析了LPB工艺后微观结构和残余应力的演变。其次，通过拉伸试验研究了处理后样品的拉伸行为。最后，揭示了LPB工艺诱导Inconel 718的微观强化机制。结果表明，LPB工艺后峰值压缩应力增加了4.2倍。LPB工艺引起的晶粒细化归因于平均取向差的增加和高角度晶界（HAGBs）的形成。屈服强度的提高取决于平均间距的减小和HAGBs的增加。
