Date:

2025-10-16

Title of Paper:

A post-treatment to reduce stress concentration sensitivity under intermediate-temperature fatigue in GH4169: High-energy impact composite modification

Journal:

Transactions of Materials Research

Summary:

The study focuses on a novel post-treatment method, high-energy impact composite modification, combining mechanical shot peening and laser shock processing to improve the fatigue performance of the nickel-based superalloy GH4169 at intermediate temperatures. The synergistic interaction between mechanical impact (SP-induced plastic deformation) and laser-induced shock waves enabled a 2.5-fold increase in effective treatment depth (up to 1500 ​μm) compared to SP alone (400 ​μm), while achieving a surface hardness of 520 HV and compressive residual stress of −1465 MPa, exceeding single-process results by 4.5% and 54.2%, respectively. The dual-impact approach significantly enhanced surface hardness and compressive residual stress, addressing the high sensitivity to stress concentration. Experimental results demonstrate that HEICM eliminated stress concentration sensitivity at 650 ​°C, elevating the fatigue limit of notched specimens (Kt ​= ​3) to 638 ​MPa – equivalent to the fatigue strength of smooth specimens (Kt ​= ​1) in conventional grinding states (636 ​MPa). This represents a 116% improvement over untreated notched specimens (295 ​MPa) and surpasses SP-treated counterparts (446 ​MPa) by 43%, thereby extending the fatigue life of GH4169 alloys in aerospace applications.

Co-author:

Guoxin Lu, Qiang Wang, Bonnie Attard, Arif Rochman, Guofang Zhang, Luqing Cui, Zhong Ji, Glenn Cassar

Volume:

1

Page Number:

100039

Translation or Not:

No

Date of Publication:

2025-05-12