Advances in the State-of-the-Art of Hammer Forged Alloy 718 Aerospace Components

Abstract

Computer controlled hammer (CCH) forging results in a reproducible, pre-programmed hammer blow energy and blow sequence, and a record of the actual velocity, energy and operation timing for each forged component. This new capability in hammer forging allows for sophisticated hammer forging processes executed under accurate control. At the same time, it also makes the process and microstructure modeling of hammer forging possible. In this study, hammer forging of Alloy 71 8 was performed run using a computer controlled hammer, and the microstructure and properties of the forged disks were evaluated. The process and microstructure modeling of the hammer forging was performed and correlated with experimental results. The results indicate that hammer forging can be run under accurate control and produce disks with high quality of microstructures and properties. This research also shows process and microstructure modeling of hammer forging is a powerful tool for the process development of high quality Alloy 71 8 components. Superallo~s 718. 625. 706 and Various Dtrivatives Edited b> E.A. Loria TblS (The Minerals. Metals &r Materials Societ~.

Simulation of Dynamic and Meta-Dynamic Recrystallization Behavior of Forged Alloy 718 Parts Using a Multi-Class Grain Size Model

“…The advantage of this test method is the linear increase of the effective strain over the radius at a constant local strain rate. In order to simulate the real process parameters of screw presses [ 3 , 8 , 11 ] and forging hammers [ 5 , 12 , 13 , 14 ], the following temperatures, strain rates and two differentiated initial structures were selected and summarized in Table 2 . In order to differentiate between DRX and MDRX [ 3 , 9 , 21 , 23 , 24 , 25 , 26 ], the same forming conditions were applied to all tests where quenching was conducted either directly after forming or after 5 and 15 s holding time.…”

“…During the production of aircraft parts from alloy 718, the material undergoes several forging steps and heat treatments [ 1 , 2 ]. In case of the forming equipment, such as screw presses and hydraulic or counterblow hammers, the difference in the energy input leads to difference in the recrystallization behavior of the material and thus leads to a variation in the microstructure of the final component [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. An optimization of the process parameters to adjust the microstructural and mechanical properties is essential.…”

Lessons Learned from the Development, Application and Advancement of Alloy 718

“…Alloy 718 can be forged at very high strain rates (hammer forging) or very low strain rates for superplastic forming. [6,7,8] Alloy 718 has and continues to be processed by casting processes of all types and sizes to obtain mechanical properties. [5 -9] This material is readily welded to support fabrication and repair processes.…”

Modeling and Simulation of Alloy 718 Microstructure and Mechanical Properties

“…Material models have been linked with FEM models to simulate bulk deformation and microstructure evolution in high strain-rate hammer forging of turbine engine disks. [35] These efforts were extremely successful in predicting the evolution of microstructure basis dynamic and meta-dynamic recrystallization, as well as grain growth resulting from adiabatic heating during the high strain-rate manufacturing process.…”