Direct metal deposition using a wire fed high power diode laser is a feasible process to form multiple layers of Waspaloy deposit at excellent deposition rates. In conjunction with a manipulation system, a complex three-dimensional structure could be fabricated offering promising applications for repair, feature addition and new component manufacture. Understanding the microstructure and mechanical properties of the material, especially one such as Waspaloy which is used in aerospace engines, is crucial to ensure its performance. Building parts layer-by-layer causes dynamic changes in the underlying substrate and the previously deposited layers due to the thermal cycling experienced. The heating and cooling rates during the deposition process affect the microstructure of the alloy which has an important impact on the mechanical properties of the material.
The objective of this study is to evaluate the microstructural evolution during deposition, the changes in microhardness when multiple layers are deposited and to relate these to the thermal cycles arising from layer deposition.