OPTILAM

The objective of the OPTILAM project is to develop local diagnostic tools at the bath scale for the determination of the microstructures of parts manufactured by the L-PBF (laser powder bed fusion) process. The project thus aims to: (1) Evaluate in situ, from an existing instrumented bench, the absorption of laser energy in the solid phase of the powder bed (with a controlled density) and in the liquid phase ( melted bath) of the L-PBF process from 3 laser sources: IR reference source, green laser and blue laser, these last 2 sources allowing to modify the absorption levels; (2) To analyze in situ the ejected vapor (in addition to the coaxial IR and visible sensors already existing on the device) from the diagnostic means (optical, spectroscopic, laser) crossed which will be installed on the bench. These analyses will allow to estimate the precise level of laser-material interaction and will serve as a basis to test the influence of the deposited energy on the vaporization rate, the sizes of the molten zone and the characteristics of the phases present; (3) Characterize the materials/structures fabricated from the different sources in terms of microstructures and mechanical properties at different scales, using in particular local nano-indentation and tomography measurements and measurements of physical properties such as electrical conduction; (4) Correlate the in situ measurements, the multiscale properties to demonstrate the ability of the data from the instrumented bench to accurately describe the physics of the L-PBF process and to contribute to the prediction of a microstructure. (5) Validate the results obtained from instrumented benches on an industrial machine in order to demonstrate the possibility of adapting and using local diagnostic tools on instrumented benches, at the scale of the melt, for the determination of a microstructure.