Gradient nanostructure enabled exceptional fretting fatigue properties of Inconel 718 superalloy through submerged abrasive waterjet peening
Shulei Yao, Yuxin Chi, Xianhao ZHU, Kaiming Zhang, T.‐M. Lu, Kai-Shang Li, Ning Wang, Chengcheng Zhang, Shuang Liu, Xiancheng Zhang, Shan‐Tung Tu
Abstract
Submerged Abrasive Waterjet Peening (SAWJP) shows great application potential in augmenting the fatigue properties of metallic parts. Thus, the present work aims to investigate the influence of SAWJP on the Surface Integrity (SI) and Fretting Fatigue (FF) properties of Inconel 718 (IN718) superalloy and illustrate the microstructural evolution, FF life improvement, and fretting wear mechanism. First, the SI of the IN718 specimen was examined following treatment via SAWJP. Results showed that the specimen subjected to SAWJP formed a total plastic deformation layer of 56 μm. The maximum microhardness and Compressive Residual Stress (CRS) measured across the depth of the SAWJP-treated specimens exhibited an increase in values ranging between 522–541 HV and 1171–1380 MPa, respectively. The FF test results of the specimen before and after SAWJP treatment at ambient temperatures indicated that the FF life of the SAWJP-treated specimen surpassed that of the as-received specimen by a factor of 2.81. The examination of the FF fracture, contact surface, and crack propagation behavior revealed the crucial factors contributing to the enhanced FF resistance of the IN718 specimen, including the gradient nanostructure characterized by ultra-refined grains, substantial CRS, and elevated microhardness, which were all induced by the SAWJP treatment.