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Additive Manufacturing (AM) or additive layer manufacturing such as LMD-CLAD® has gained a lot of interest for industrial applications in aeronautics and medicine, taking advantage of the ability to build complex geometries and scale parts.
However, due to the high cost of some manufactured parts and construction duration (eg: 155 hours for large part with 600mm*350mm*34mm in respectively diameter, height and thickness), parts must be successfully manufactured at the first try.
For that reason, local residual stresses, strains, cracks and mismatch induced by the process in manufactured parts need to be handled before construction.
In this work, thermal and distortion measurements on Titanium’TA6V’ material were used to understand the effects of the deposition strategies on the time cycle. Analysis show that time cycle has a great influence on the microstructure, residual stresses and distortions. A numerical model called ‘micro-meso’ is designed to model the LMD-CLAD ® process. This model helped analyzing the time cycle and construction strategies influences on small samples. Thermal and distortion comparison are done between numerical results and manufactured sample measurements. Micro-meso model was inserted in a ‘macro model’ which is a scale part. This simulation method helps to drastically reduce computation time of large parts. Then, the distortions trends were located and corrected before the scale part construction.
Distortion trends of LMD-CLAD® can be studied through micro-meso-macro model in a short time ‘48h’ compared to 155h for large parts simulated with ordinary PC (core i5 8Gbs RAM). The numerical tool helped us optimizing the construction strategy and jigs. It was also used to reduce process setup, to design a distortion compensated part model, and modify the part design according to estimated trends.
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