S. S. Babu, W. Zhang, Y. P. Yang, S. P. Vaze, Edison Welding Institute, Columbus, OH
Laser Powder Deposition (LPD) for component manufacture and repair offers some unique solutions for high temperature aerospace applications. LPD has been demonstrated as a promising technique for rapidly producing Ti-6Al-4V aircraft parts. Significant efforts toward the development and implementation of the manufacturing process have given birth to a new industry utilizing an entirely new manufacturing process for titanium structure fabrication. Inherent to LPD is the ability to add material for repair of critical gas turbine engine components with minimal heat affect to the underlying material. Also, due to the nature of LPD, hard coatings can be achieved without heat treatment producing durable hard surfaces on soft materials.
To help LPD development and maturation for a complex geometry, an integrated computational finite element model is being developed to predict the fluid flow, thermal profile, microstructure distribution, residual stress, distortion, and structure performance during high temperature service. Several commercial software (FLUENT, Thermo-Calc, and ABAQUS) and EWI developed software weldFEA, E-Weld predictor and Q-Weld were used in the development. The model can provide quantitative information on the effects of changes in process parameters on deposit characteristics, residual stress, distortion and structure performance during service. Several examples of turbine parts repair have been included in this paper to demonstrate the capabilities of this integrated model. The examples include the prediction of the shape of the as-deposited melting zone based on fluid flow and the evaluation of the cracking tendency based on the microstructure and residual stresses.
Summary: Laser Powder Deposition (LPD) for component manufacture and repair offers some unique solutions for high temperature aerospace applications. To help LPD development and maturation for a complex geometry, an integrated computational finite element model is being developed to predict the fluid flow, thermal profile, microstructure distribution, residual stress, distortion, and structure performance during high temperature service.
