This work is focused on the influence of heat treatment of a part produced by the SLM (selective laser melting) method of stainless steel, 316L. Two heat treatment regimens were tested and compared with the state without heat treatment. Subsequently, TIG (tungsten inert gas) welds were created on the base materials processed in this way. All welds were subjected to mechanical tests and microstructural analysis. The tensile test was performed both for the welded joint and for the base material in the transverse and longitudinal directions. The tensile strength values of the samples with the welded joint were compared with the values required for the base material, 316L forged steel (1.4404). Microstructural analysis revealed significant differences between samples with and without heat treatment. The results of these tests are supported by SEM analysis. EDAX (energy dispersive analysis of X-rays) semiquantitative analysis confirmed the presence of ultra-fine pores in the structure. The results of mechanical tests show that the solution annealing at 1040 °C for 0.5 h gives better results than the same heat treatment with a duration of 2 h.

• Klíčová slova
• AISI 316L, heat treatment, mechanical properties, microstructural analysis, selective laser melting, tungsten inert gas welding,
• Publikační typ
• časopisecké články MeSH

Reverse engineering is the process of creating a digital version of an existing part without any knowledge in advance about the design intent. Due to 3D printing, the reconstructed part can be rapidly fabricated for prototyping or even for practical usage. To showcase this combination, this study presents a workflow on how to restore a motorcycle braking pedal from material SS316L with the Powder Bed Fusion (PBF) technology. Firstly, the CAD model of the original braking pedal was created. Before the actual PBF printing, the braking pedal printing process was simulated to identify the possible imperfections. The printed braking pedal was then subjected to quality control in terms of the shape distortion from its CAD counterpart and strength assessments, conducted both numerically and physically. As a result, the exterior shape of the braking pedal was restored. Additionally, by means of material assessments and physical tests, it was able to prove that the restored pedal was fully functional. Finally, an approach was proposed to optimize the braking pedal with a lattice structure to utilize the advantages the PBF technology offers.

• Klíčová slova
• 3D scanning, SS316L, electronic speckle pattern interferometry, lattice structure, powder bed fusion, printing simulation, reverse engineer,
• Publikační typ
• časopisecké články MeSH

In this work, a systematic analysis of the hot deformation mechanism and a microstructure characterization of an as-cast single α-phase Mg-4.5 Li-1.5 Al alloy modified with 0.2% TiB addition, as a grain refiner, is presented. The optimized constitutive model and hot working terms of the Mg-Li alloy were also determined. The hot compression procedure of the Mg-4.5 Li-1.5 Al + 0.2 TiB alloy was performed using a DIL 805 A/D dilatometer at deformation temperatures from 250 °C to 400 °C and with strain rates of 0.01-1 s-1. The processing map adapted from a dynamic material model (DMM) of the as-cast alloy was developed through the superposition of the established instability map and power dissipation map. By considering the processing maps and microstructure characteristics, the processing window for the Mg-Li alloy were determined to be at the deformation temperature of 590 K-670 K and with a strain rate range of 0.01-0.02 s-1.

• Klíčová slova
• constitutive model, flow stress, hot compression test, magnesium alloy, microstructure evolution, processing map,
• Publikační typ
• časopisecké články MeSH

This work is focused on the analysis of the influence of welding on the properties and microstructure of the AISI316L stainless steel tube produced by 3D printing, specifically the SLM (Selective Laser Melting) method. Both non-destructive and destructive tests, including metallographic and fractographic analyses, were performed within the experiment. Microstructure analysis shows that the initial texture of the 3D print disappears toward the fuse boundary. It is evident that high temperature during welding has a positive effect on microstructure. Material failure occurred in the base material near the heat affected zone (HAZ). The results obtained show the fundamental influence of SLM technology in terms of material defects, on the properties of welded joints.

• Klíčová slova
• mechanical properties, microstructure, selective laser melting, welded joints,
• Publikační typ
• časopisecké články MeSH