PROCESSI AD ARCO, ALTRI PROCESSI DI GIUNZIONE ED INCOLLAGGIO
Sala SCIROCCO / LIBECCIO 10:00 - 10:30 Investigating the Porosity Formation in Laser Welded PBF – LB Manufactured Aluminum Parts: A Methodolo- gical Approach. K. K. Yetil, M. Scarinzi, A. G. Demir, B. Previtali (Politecnico di Milano), M. Pedemonte, A. Bazurro, M. Moretello (IIS) In recent years, Additive Manufacturing technologies are being va- stly demanded and studied due to their enabling features that serve for the production of highly customized parts. As one of the leading additive manufacturing technologies in the market, Powder Bed Fu- sion – Laser Beam (PBF – LB) continues playing a crucial role in sec- tors like aerospace, mold and dies and biomedical where weight re- duction, part precision, mechanical reliability and customization are the critical aims. Naturally, as the technologies mature and sectors advance, the need for parts with larger dimensions also increases. However, simply increasing the machine sizes along with using multi- ple laser sources to fulfil this need brings technological and process challenges, such as thermal deformations, powder handling, process chamber inertization and calibration errors, that might directly or indi- rectly increase the probability of a defective part. One alternative can be the use of assembly and joining methods after PBF – LB production of the parts. In this way, several parts can be produced in parallel to decrease the production times and joined in virtually any shape and size. Among joining methods, one of the most robust solutions is consi- dered laser welding as it enables high degree of automation and spe- ed with minimal distortion in the part. To this day, several researchers made efforts on the laser weldability of various additively manufactu- red alloys such stainless steel, nickel-based and titanium-based alloys and obtained almost seamless results with good mechanical proper- ties. Nonetheless, when it comes to the laser weldability of PBF – LB manufactured aluminum parts, the processability gets limited by the high porosity formation. The present work aims to investigate this issue and proposes a methodological approach to reveal the root cause of the problem. In this context, several aspects of laser welding were listed and investigated, namely, the effect of nature of the welding process (fusion based and friction stir welding), the modality of the weld,
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GNS 12 | Programma
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