Modelling of laser repair of single crystal nickel based superalloys

Tao, Tao (2013). Modelling of laser repair of single crystal nickel based superalloys. University of Birmingham. M.Phil.

Preview

Tao13MPhil.pdf
PDF - Accepted Version
Download (5MB)

Abstract

Single crystal nickel-base superalloys have been used extensively in high-temperature gas turbines as blades and vanes, due to a combination of superior strength, ductility and crack and creep resistance at elevated temperatures. Although modern gas turbines are extremely reliable, wear and other types of damage, e.g. blade tip erosion and thermal fatigue cracks to components, especially those under severe thermo-mechanical and corrosive conditions are unavoidable. And the high replacement costs of gas turbine engine components make the repair of damaged components extremely desirable. However, experimental understanding is considered to be time and cost consuming. It follows that developing simulation methods is of necessity to aid in the repair and reshaping of damaged gas turbine engines. In this project, analytical models have been developed for the repair of commercial single crystal superalloys, i.e. CMSX-4, main concern is put on the simulation process of heat and mass transfer, so that relationship of laser, powder injection and substrate has been studied and predicted; moreover, defining processing parameters, correlation between solidification conditions and microstructure has been established using CET model so that the operating conditions can be adjusted to produce epitaxial growth onto the single crystal substrate.

Type of Work:

Thesis (Masters by Research > M.Phil.)

Award Type:

Masters by Research > M.Phil.

Supervisor(s):