Microstructure dependence of process behaviour of y strengthened nickel-based superalloys during rotary friction welding

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Di Simone, Federica (2019). Microstructure dependence of process behaviour of y strengthened nickel-based superalloys during rotary friction welding. University of Birmingham. Ph.D.

DiSimone2019PhD.pdf
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Abstract

Nickel-base Superalloys are the material of choice for turbine disks, which experience consistently high temperatures and stresses during Operation. Nowadays Rotary Friction Welding is widely used for joining disks because this process can lead to a high integrity joint, however the process is difficult to control and undesirable changes to the microstructure in the weld zone can affect the component performance.
During a joining process temperatures and strain rates reach such elevated values that the microstructure is heavily changed. What it is needed is to capture the impact of microstructure evolution and the associated mechanical properties on joint integrity. To achieve this, a mean field model has been incorporated into a finite element model in Order to evaluate the y’ evolution during RFW Simulation and algorithms for recrystallisation as well as grain growth behavior has been coded in MatLab. The methods and models developed have been used to produce a series of maps which predict the final microstructure after joining disks. These maps will be used as a guide in future welding experiments in order to widerstand how to improve the key process parameters used in production, and therefore improve stability and safety during working conditions and save experimental costs.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):