https://popups.uliege.be/esaform21/index.php?id=2339 Publications of Auteurs Pierre Joyot fr 0 https://popups.uliege.be/esaform21/index.php?id=2488 Originally issued from cladding, the LMD-p process widens the field of possibilities in terms of manufacturing. Depending on the targeted application, the needs regarding the track geometry are different and the ability to adapt it is a key challenge. In LMD-p, the laser beam attenuation as well as the powder particles preheating are both determined by laser-powder interactions before the powder reaches the substrate. The track dimensions are directly correlated to the melt pool size: a larger pool will tend to capture more powder resulting in a higher deposition rate. The model presented here intends to determine, for a given working distance, the partition of energy, and to estimate the area of the generated melt pool and finally the dimensions of the deposited track. It is first based on a semi-analytical approach that models the powder distribution and calculates the transmitted power to both substrate and powder particles. The attenuated power density is then an input for a light Eulerian thermal simulation from which the contour of the molten zone is extracted. Several iterations are carried out to account for the energy loss caused by the heating and melting of the powder entering the pool. Lastly, the track dimensions are estimated from the stabilized melt pool configuration. Track geometries obtained with a BeAM® machine are compared to the model predictions. Such an approach opens very interesting perspectives in studying the influence of the working distance and its optimization for a given material and/or a given application. Tue, 23 Mar 2021 20:31:42 +0100 Tue, 30 Mar 2021 09:44:45 +0200 https://popups.uliege.be/esaform21/index.php?id=2488 https://popups.uliege.be/esaform21/index.php?id=2335 Automated fiber placement processes could be combined with additive manufacturing to produce more functionally complex composite structures with more flexibility. The challenge is to add functions or reinforcements to PEEK/carbon composite parts manufactured by automated fiber placement process, with additive manufacturing by fused filament fabrication. This consists of extruding a molten polymer through a nozzle to create a 3D part. Bonding between polymer filaments is a thermally driven phenomenon and determines the integrity and the final mechanical strength of the printed part. 3d-printing high performance polymers is still very challenging because they involve high thermal gradients during the process. The purpose of this work is to find a process window where the bonding strength is maximized between the composite laminate and the first layer of printed polymer, and inside the printed function as well. Experimental measurements of the temperature profiles at the interface between a composite substrate and 3d-printed PEI under different processing conditions were carried out. The interface was observed using microscopic sections. The methodology for studying the impact of printing parameters on the cohesion and adhesion of printed parts with a composite laminate is described. This work provides insights about the influence of processing conditions on the bond formation between high-performance polymer surfaces. It highlights the importance of controlling the thermal history of the materials all along the process. Tue, 23 Mar 2021 16:58:33 +0100 Tue, 30 Mar 2021 10:21:28 +0200 https://popups.uliege.be/esaform21/index.php?id=2335