University of Birmingham, School of Metallurgy and Materials, UK, announces that researchers have developed analytical models for the repair of commercial single crystal nickel-base superalloys. Composite element test (CET) modeling was used by researchers to define processing parameters and the correlation between solidification conditions and microstructure. Models are designed to predict the relationship of laser treatment and powder injection and their effects on the substrate. This allows the operating conditions to be adjusted to produce epitaxial growth onto the single crystal substrate.
Single crystal nickel-base superalloys have been used extensively in high-temperature gas turbine 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 are unavoidable, such as blade tip erosion and thermal fatigue cracks to components, especially those under severe thermomechanical and corrosive conditions. The high replacement costs of gas turbine engine components make the repair of damaged components extremely beneficial. The CET simulation methods have been designed to aid in the repair of these and similar parts and products.
In this project, analytical models have been developed for the repair of commercial single crystal superalloys, i.e., CMSX-4. The 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.
Prof. Nils Warnken, School of Metallurgy & Materials, [email protected]
