This study investigates the fatigue behavior of additively manufactured AlSi10Mg under cyclic loading using Laser Powder Bed Fusion (L-PBF) technology. The research addresses two key aspects: the size effect across three distinct geometries, and the influence of mean stress on one geometry under both push-pull and tension-tension loading conditions. The findings provide valuable insights into how geometry and mean stress affect the fatigue resistance of L-PBF AlSi10Mg, contributing to the optimization of additive manufacturing processes for high-performance applications.

In the present work, the impact of defect geometry, size and position on the high cycle fatigue (HCF) properties was studied on AlSi10Mg alloy manufactured by Laser Powder Bed Fusion (LPBF). Different types and variations of heat treatment were applied on fatigue testing specimens from several building platforms. To investigate the influence of porosity and its characteristics on fatigue crack initiation, propagation and fatigue life, specimens were tested in the state of as built, after three types of annealing with various impact on supersaturated eutectic Si, and after two types of T6 heat treatment resulting in dissolution of Si network and reprecipitation of Si particles (total of 6 configurations of heat treatment). Fatigue crack growth and propagation mechanism together with defect evaluation were determined by fractographic analysis, while the influence of heat treatment on microstructural transformations was analyzed using light and scanning electron microscopy (SEM) combined with electron backscatter diffraction (EBSD). Based on the results, maximum stress intensity factor was determined, and the prediction of fatigue limit was established for each material state. The synergistic effect of heat treatment and defects properties on high cycle fatigue is discussed.

This study explores the fatigue behavior of additively manufactured AlSi10Mg components under cyclic loading, with a specific focus on the influence of specimen position on the build platform (BP) on its fatigue life. Utilizing the well-established Laser Powder Bed Fusion (L-PBF) process—specifically the Concept Laser M2 system—experimental data collected over the past four years, including distinct S-N curves, have been used to identify regions of reduced fatigue performance across the build platform.To systematically investigate this spatial variation, each built platform was analyzed individually, with particular attention paid to unpredictable specimens and their precise locations on the print bed. A dedicated experimental platform of fatigue specimens was prepared, comprising 44 specimens divided into two groups of applied load levels. This setup enabled the first quantitative assessment of the correlation between spatial build position and fatigue strength in L-PBF-fabricated AlSi10Mg.In addition, four different heat treatment conditions were evaluated to understand their impact on fatigue resistance. Special emphasis was placed on the manufacturer-recommended thermal treatment for AlSi10Mg, providing a comprehensive perspective on the interplay between printing position, thermal processing, and fatigue performance. These findings offer critical insights for optimizing additive manufacturing strategies in demanding structural applications.

Article deals with analysis on influence of post-process settings profiles in the Polyworks software and its influence on measuring bias (difference between average surface profile deviation and artifacts reference value) and standard deviation of measured data. The comparison was evaluated on glossy artifact with freeform surfaces. Setting with least bias and standard deviation was than used to evaluate repeatability and systematic measurement error and minimum tolerance bandwidth Tmin according to VDA 5 and MSA 4, respectively for three conceptions of laser scanning technologies available on today's market. Cartesian CMM LK Altera S with laser scanner Nikon LC15Dx (automated technology), Measuring arm Nikon MCAx S30 with laser scanner Nikon H120 (manual technology) and optically tracked handheld device Metronor M-Scan with laser scanner Nikon H120 (manual technology). The conclusions of the study can serve as a guide in technology selection for reverse engineering input data acquisition. Subsequently, the optimal parameters of the post-process settings (for glossy surfaces) in the Polyworks software are listed.

This study investigates the fatigue strength characteristics of AlSi10Mg specimens produced by Laser Powder Bed Fusion (L-PBF) and heat-treated at 200 degrees C for 2 h. A particular focus of this paper is on evaluating the potential of Laser Shock Peening (LSP) to enhance their fatigue performance. The hourglass specimens were printed in a single batch, resulting in six distinct groups for testing. While three series remained in the as-built state, the other three underwent machining to achieve specific dimensions and surface roughness. Additionally, two variants of the Laser Shock Peening process were applied to two groups of as-built specimens and to two groups of machined specimens. Fatigue testing was performed using a resonant pulsator at the load ratio of R = 0.1. The surface roughness and depth profiles of residual stress were analyzed. A specific focus was set to identify the pore closure due to applied LSP showing that the chosen LSP configurations significantly modify the porosity of additively manufactured AlSi10Mg samples. The results show that the more energy-intensive LSP process improves the fatigue behavior to a point where the difference in fatigue life between machined and as-built specimens becomes minor.

The present study focuses on the thermal response of AlSi10Mg samples under cyclic dynamic loading, consequence of the self-heating effect. The samples are additively manufactured from AlSi10Mg aluminum alloy using the Laser Power Bed Fusion (L-PBF) technology. This paper discusses the prospect of applying thermographic methods to establish the standard S-N curve for fatigue life prediction using fewer samples than currently necessary and investigating the fatigue limit transition. The heat generation (self-heating) by the specimen during loading is analyzed using specific self-heating tests, which consist in gradually increasing the amplitude of loading for a certain number of cycles while monitoring the temperature of the specimen. Subsequently, this variable is processed as an input parameter within additional fatigue analyses. The effect of four different heat treatments was also considered, and some conclusions are drawn.

The paper describes experimental results of multiaxial tests on AM AlSi10Mg cavity specimens with the special focus on the phase shift effect. Four typical representatives of multiaxial fatigue strength criteria are assessed to check the correlation of their results with fatigue experiments. The use of the QCP and Liu-Zenner criteria provide overall better results than the Dang Van criterion and the Crosland criterion, but none of the four evaluated criteria fits well to both checked multiaxial loading configurations. The potential reasons for the found discrepancies are commented in the discussion section.

This study investigates the varying thermal response of additively manufactured specimens made of AlSi10Mg and subjected to cyclic loading. It is well known that the thermal response is driven primarily by the self-heating effect. The paper explores the possibility of employing thermographic methods to establish an S-N curve for fatigue life prediction with the use of fewer specimens than are traditionally required for an S-N curve established from constant-amplitude fatigue tests. Specific self-heating step tests are conducted by gradually increasing the loading amplitude while monitoring the temperature of the specimen. A new approach is introduced to assess the lower limitation of the existing Fargione method, which addresses the absence of the fatigue limit threshold in previously published works. The validity of this approach is compared with our own experimental data. This new dataset concerns additively manufactured (AM) specimens made from AlSi10Mg powder, which were all printed on a single platform. To observe the sensitivity of the updated approach, four groups with different heat treatments were evaluated. Evaluation of four heat treatments on AM samples of AlSi10Mg with focus on fatigue life Fatigue limits estimated based on thermal response and combination of static parameters Self-heating tests result in a thermal response unique for every heat treatment Fatigue life curve estimation using two different approaches

This research aims to analyze how varying heat treatment conditions affect the fatigue life performance of additively manufactured specimens from AlSi10Mg. The study focuses on the transition from High Cycle Fatigue (HCF) to the Fatigue Limit (FL) domain. To eliminate inconsistencies, four sets of hourglass specimens were created through Laser Power Bed Fusion (L-PBF) technology within one build cycle. All fatigue specimens were of the same geometry and with as-built surface, but four different heat treatments were applied. Fatigue testing was conducted in the uniaxial tension domain using a resonant pulsator with the load ratio of 0.1. To further characterize the different heat treatments of the specimens, a thermal camera was utilized to measure the temperature response during cyclic loading. The observed increase of temperature, referred to as the Self-Heating effect (S-H), is directly related to heat dissipation during cyclic loading. A test with blocks of subsequently increasing load amplitude was conducted to establish a stabilized temperature response in each block for further analysis. The pairs of the stress amplitude levels, and stabilized temperatures can be used as a characteristics of heat dissipation during cyclic loading related to different heat treatments.

This research delves into the analysis of various properties of additively manufactured specimens from AlSi10Mg with an as-printed surface, comparing the effects of three distinct heat treatments with an untreated variant. The study assesses both static properties and fatigue responses for each heat treatment, including a detailed examination of the microstructures. In the high-cycle fatigue region, the treatment causing the silicon network to break provides the best output, while the low-cycle fatigue response is dominated by the heat treatment by artificial ageing alone. In addition, this paper introduces a novel proposal on fatigue limit estimation inspired by Luong's and Risitano's approaches based on the self-heating phenomenon. Demonstrating efficiency in its simplicity, this approach holds promise for estimating the fatigue limit. This method provides a cost-efficient and time-saving way to determine the fatigue limit transition on the basis of fewer samples than the traditional methods require.

The present study focuses on the high cycle fatigue domain (HCF) response of additively manufactured (AM) specimens from AlSi10Mg powder. The specimens are produced using Laser Powder Bed Fusion (LPBF) technology. The main objective of this work is to analyse the fatigue strength of specimens coming from platforms with different level of recycling the input powder, and to investigate the stability of LPBF technology as regards this aspect. The effect of printing powder recycling is questioned. Three different heat treatment setups were applied. Temperature of specimens during the experiment is parallelly monitored to describe the temperature changes during dynamic cyclic loading in order to estimate the fatigue life behaviour in a cost-effective manner.

This study explores the varying thermal response of additively manufactured samples of AlSi10Mg subjected to cyclic loading. The thermal response is driven primarily by the self-heating effect. The paper explores the viability of employing thermographic methods to establish an S-N curve for fatigue life prediction with fewer samples than traditionally required from constant-amplitude tests. Specific Self-Heating tests are conducted, gradually increasing the loading amplitude while monitoring the specimen’s temperature. The validity of evaluated solution is compared with the own experimental data including the impact of four heat treatments on the samples from one AM batch, leading to valuable insights and conclusions.

This study focuses on analyzing the thermal response induced by the self-heating effect during cyclic loading of additively manufactured (AM) specimens made from AlSi10Mg aluminum alloy and on its correlation with their fatigue life performance. Four different specimen designs were tested to assess the applicability of various thermographic methods for predicting the fatigue response. These methods focus on estimating the fatigue limit (the Luong method and its versions) or the S-N curve (the Fargione method) from the temperature response of one specimen which is loaded on multiple subsequently increasing levels of the stress amplitude. Such methods could reduce the costs of fatigue experiments by speeding up the estimation of fatigue life performance. The analyses documented in this paper show their large potential (above all in the case of the Fargione method), but also their weaknesses and the need for a more rigorous and broader validation on new experimental data.

This paper aims at an in-depth and comprehensive analysis of mechanical and microstructural properties of AISI 316L austenitic stainless steel (W. Nr. 1.4404, CL20ES) produced by laser powder bed fusion (LPBF) additive manufacturing (AM) technology. The experiment in its first part includes an extensive study of the anisotropy of mechanical and microstructural properties in relation to the built orientation and the direction of loading, which showed significant differences in tensile properties among samples. The second part of the experiment is devoted to the influence of the process parameter focus level (FL) on mechanical properties, where a 48% increase in notched toughness was recorded when the level of laser focus was identical to the level of melting. The FL parameter is not normally considered a process parameter; however, it can be intentionally changed in the service settings of the machine or by incorrect machine repair and maintenance. Evaluation of mechanical and microstructural properties was performed using the tensile test, Charpy impact test, Brinell hardness measurement, microhardness matrix measurement, porosity analysis, scanning electron microscopy (SEM), and optical microscopy. Across the whole spectrum of samples, performed analysis confirmed the high quality of LPBF additive manufactured material, which can be compared with conventionally produced material. A very low level of porosity in the range of 0.036 to 0.103% was found. Microstructural investigation of solution annealed (1070 °C) tensile test samples showed an outstanding tendency to recrystallization, grain polygonization, annealing twins formation, and even distribution of carbides in solid solution.

Structural Health Monitoring (SHM) of composite structures leads to greater safety during operation and reduces the cost of regular inspections. Impact damage detection is an important SHM task. Since impact damage can significantly reduce the lifetime of composite structures, sensors for impact damage are of great interest. Carbon Fiber Sensors (CFSs) can be used to detect composite damage. CFSs are lightweight and compact, and they can be integrated during the manufacturing process. In our study, CFSs were manufactured from three types of carbon fiber tows and were integrated into different layers of the lay-up in order to investigate the influence on impact damage detection. The effect of mechanical loading and temperature change on the measured electrical resistance was investigated during cyclic flexural tests. It was revealed that, it is possible to distinguish between changes in measured signals due to impact and due mechanical loading. The change in the measured electrical signal caused by temperature can be eliminated. CFSs can be used for impact damage detection of a glass fabric composite. A combination of thermography and CFSs as an active heating element also provides good results in the field of impact damage detection

Laser polishing process is a promising technology for post-processing of complex parts prepared by additive manufacturing. In this study, the nanosecond laser polishing process was employed to improve a surface roughness of SLM (selective laser melting) prepared 316 L stainless steel with different part orientation (0°, 15°, 45°, 75° and 90°) during construction. Afterwards, the changes of surface topography, morphology and the cross-sectional microstructure before and after laser polishing were investigated. Additionally, the study also focusses on the process of 3D printing, especially on material porosity after sintering process. The results obtained from computer tomography showed that the samples were well prepared, with porosity below 0.019%. After laser polishing, surface roughness represented by Sa and Sz values was reduced for all printed samples regardless to their construction angle with similar laser and scanning parameters. The maximum roughness reduction reaches more than 90% (from Sa = 9.8 µm to Sa = 0.77 µm). Moreover that, other surface analysis established the best conditions for laser polishing. Finally, from the cross-section, the microstructure analysis was done and thickness of melted layer, heat-affected zone followed by microhardness measurement was estimated. Except of one applied condition, all samples were very homogenic with no damages in intersection layer. Simultaneously, there were no changes in microhardness after laser process observed.

S .................................................................................................................................................................................... 16 1. CHARACTERIZATION OF AM POLYMER-BASED MATERIALS ................................................................................. 17 COMPARISON OF ROUGHNESS OF DIFFERENT PARTS OBTAINED BY ADDITIVE MANUFACTURING ................ 18 ANALYSIS OF DIFFERENT PROCESS PARAMETERS OF 3D PRINTING AND MICRO-EDM FOR FABRICATING PRECISE MICRO-HOLE IN CFRP COMPOSITES................................................................................................................................ 19 TENSILE PROPERTIES OF FDM PRINTED PLA SPECIMENS: INFLUENCE OF PRINTING PARAMETERS ............. 21 IMMERSED THERMO-MECHANICAL ANALYSIS OF LASER POWDER BED FUSION PROCESSES ............................. 22 INFLUENCE OF TEMPERATURE ON THE TENSILE BEHAVIOUR OF FDM PRINTED ABS AT DIFFERENT SPATIAL ORIENTATIONS .......................................................................................................................................................................... 24 INFLUENCE OF WALL LAYER NUMBER AROUND BRASS INSERTS IN 3D PRINTED SPECIMENS SUBJECTED TO AXIAL PULL-OUT FORCE .................................................................................................................................................................... 25 IMPACT PROPERTIES OF LASER SINTERED POLYAMIDE, ACCORDING TO BUILDING ORIENTATION ............... 26 RRAM A ROUND-ROBIN ON ADDITIVELY MANUFACTURED PLASTICS EXPERIMENT .......................................... 28 THE INFLUENCE OF DOG-BONE SHAPED SPECIMEN GEOMETRY ON TENSILE TEST RESULTS OF FUSED FILAMENT FABRICATED PA12 .............................................................................................................................................................. 30 2. FATIGUE AND FRACTURE OF AM MATERIALS ............................................................................................................. 32 LOW CYCLE FATIGUE BEHAVIOUR OF 304L STAINLESS STEEL FABRICATED BY SELECTIVE LASER MELTING ............................................................................................................................................................................................................................... 33 ANALYSIS AND MODELLING OF DAMAGE MECHANISM IN FFF 3D PRINTED LATTICE STRUCTURE DURING COMPRESSION LOADING .......................................................................................................................................................................... 34 MODE I FRACTURE TOUGHNESS OF FDM PRINTED PLA SPECIMENS: INFLUENCE OF PRINTING PARAMETERS ................................................................................................................................................................................................. 36 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22 Brno, Czech Rep., 4th –5th February 2022 & Online H2020-WIDESPREAD-2018-03 Project No. 857124 8 FRACTURE MECHANICS PARAMETERS ASSESSMENT OF QUASI-BRITTLE PLA POLYMER AND PLA-X COMPOSITE ..................................................................................................................................................................................................... 37 ENERGY-BASED METHOD FOR ANALYSING FATIGUE PROPERTIES OF ADDITIVELY MANUFACTURED ALSI10MG......................................................................................................................................................................................................... 38 EXPERIMENTAL DETERMINATION OF FRACTURE MECHANICS PARAMETERS ON RING-SHAPED SPECIMENS WITH DIFFERENT CRACK LENGTHS ................................................................................................................................................... 40 3. CHARACTERIZATION OF AM METALLIC MATERIALS ............................................................................................... 41 EFFECT OF HEAT TREATMENT ON THE TRIP BEHAVIOR OF ADDITIVE MANUFACTURED STAINLESS STEEL ............................................................................................................................................................................................................................... 42 EFFECT OF BUILDING DIRECTION AND HEAT TREATMENT ON TENSILE PROPERTIES OF INCONEL 939 PREPARED BY ADDITIVE MANUFACTURING .................................................................................................................................. 43 STUDY OF HEAT TREATMENT OF SELECTIVE LASER MELTED ALSI10MG SPECIMENS ............................................ 44 NITI-POWDERS BEHAVIOR AT LASER INTERACTION ................................................................................................................ 46 THE EVOLUTION OF THERMAL DISTORTION AND STRESSES AT MACRO SCALE FOR METAL ADDITIVELY MANUFACTURED PART ............................................................................................................................................................................. 47 A COMPARISON ON STATIC AND FATIGUE BEHAVIOUR BETWEEN TRADITIONAL AND SLM AISI 316L ......... 48 ROLE OF SURFACE FINISH ON THE FATIGUE BEHAVIOUR OF L-PBF IN718 USING MINIATURE SPECIMEN .. 50 4. PROPERTIES AND MODELS OF AM MATERIALS AND METAMATERIALS ........................................................... 51 2D TRIANGULAR-LIKE ADDITIVELY MANUFACTURED MULTIMATERIAL LATTICES: AN EXPERIMENTAL STUDY ................................................................................................................................................................................................................ 52 INFLUENCE OF INFILL TOPOLOGY ON THE FLEXURAL STIFFNESS OF FDM PRODUCED PLA ................................ 53 MECHANICAL BEHAVIOUR OF SOFT MEMBRANES: SIMULATION AND POSSIBLE AM BIOMIMICKING TISSUES ............................................................................................................................................................................................................. 55 ADDITIVELY MANUFACTURED TRIPLY PERIODIC MINIMALLY SURFACE STRUCTURES FOR BIOMECHANICAL APPLICATION ........................................................................................................................................................... 56 CFD-DEM APPROACH TOWARDS A MULTI-TRACK SELECTIVE LASER MELTING ........................................................ 57 DESIGN OF CELLULAR STRUCTURES FABRICATED BY THE ADDITIVE MANUFACTURING METHOD ................ 59 ANALYSIS OF MECHANICAL PROPERTIES OF BULK ARCHITECTURED MATERIALS .................................................. 61 5. AM TECHNOLOGIES: ADVANCEMENTS & NEW EXPERIENCES ............................................................................... 62 SURFACE WELDING AS AN ADDITIVE MANUFACTURING TECHNIQUE TO IMPROVE RAIL CRACK RESISTANCE ................................................................................................................................................................................................... 63 3D DIGITALIZATION AND MODELLING OF CULTURAL AND HISTORICAL TREASURES OF MONTENEGRO ..... 65 CENTER FOR OPTICAL MEASUREMENTS AND RAPID PROTOTYPING CHALLENGES IN ADDITIVE MANUFACTURING ........................................................................................................................................................................................ 66 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22 Brno, Czech Rep., 4th –5th February 2022 & Online H2020-WIDESPREAD-2018-03 Project No. 857124 9 NEW METHODS FOR CAD DEVELOPMENT OF PARTS ADAPTED TO ADDITIVE PRODUCTION TECHNOLOGIES ............................................................................................................................................................................................................................... 67 IMPLEMENTATION OF ADDITIVE MANUFACTURING AT TECHLAB TEHNOPOLIS ...................................................... 68 CHALLENGES OF 3D PRINTING IMPLEMENTATION IN CIVIL ENGINEERING ................................................................. 69 PROTOTYPING OF CLAMPING MANDREL FOR PIPE WELDING BY METHOD FSW ....................................................... 71 3D METAL PRINTING DEVELOPMENT AND INNOVATION .................................................................................................... 72 3D PRINTING APPLICATIONS IN CIVIL ENGINEERING .............................................................................................................. 73 PRODUCTION PARK TORPEDO HOW TO BECOME THE MAIN CENTER OF ADDITIVE TECHNOLOGY IN CROATIA ........................................................................................................................................................................................................... 75 EXPERIMENTAL AM DRAWING TOOL ................................................................................................................................................ 76 ___________________________________________________________________ 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22 Brno, Czech Rep., 4th –5th February 2022 & Online H2020-WIDESPREAD-2018-03 Project No. 857124

This paper evaluates the effect of stress-relieving heat treatment on the AlSi10Mg alloy prepared by additive manufacturing using the Laser Powder Bed Fusion (L-PBF) with print parameters: 370 W, 1400 m/s, and 50 μm. The as-built state and four different annealing modes (240 °C/2 h, 240 °C/6 h, 300 °C/2 h, and 300 °C/2 h/water-quenched) are investigated. To determine the effect of the annealing mode on the mechanical properties of the L-PBF AlSi10Mg alloy, heat-treated samples were compared with the as-built state and with each other. The mechanical properties of the samples were determined by tensile and hardness tests. The strength in the as-built state is 488 MPa, depending on the method of heat treatment, the strength values range from 296 MPa to 417 MPa, and the HV10 hardness values are in accordance with the measured strength values. Furthermore, the microstructure of the samples was investigated by scanning electron microscopy (SEM) analysis, which was then linked to the measured mechanical properties. The composition of the microstructure of the alloy and its influence on the mechanical properties were determined by energy dispersive spectroscopy (EDS) analysis. Furthermore, the differences between the individual heat treatments in comparison with the as-built state were analyzed and the phenomenon of decomposition of the silicon network after reaching specific temperatures was discussed and confirmed. The paper evaluates the effect of dwelling time on stress relief annealing. It was found that if annealing at intermediate temperatures of 240 and 300 °C is applied, changes in structure and mechanical properties are more temperature- than dwell-time-dependent.

The most common titanium alloy used in combination with additive manufacturing is Ti-6Al-4V ELI. On the other hand, the 3D printing of β-Ti alloys is still in the stage of development of both materials and their treatment. The newly developed biomedical Ti alloys are often containing Nb, Ta, Zr. These alloys are showing very good values in terms of biocompatibility and corrosion resistance while their elastic modulus may be in the range of 30-70 GPa. The printing of these alloys is however limited by their relative novelty. Powders are not yet available through traditional commercial ways. In this work, Ti–24Nb–8Ta–4Sn specimens prepared by the selective laser melting (SLM) method were used. The porosity was evaluated by two methods: area porosity evaluated by image analysis on metallographic specimens and volume porosity evaluated by micro-computed tomography (μCT). The microstructure was observed using both light and scanning electron microscopy (SEM). The SEM was as well used for energy dispersive spectroscopy (EDS) for chemical analysis and the analysis of crystallographic orientation was conducted using the method of electron backscattered diffraction (EBSD).

The purpose of this study was to find and optimize the process parameters of producing tool steel 1.2709 at a layer thickness of 100 μm by DMLS (Direct Metal Laser Sintering). HPDC (High Pressure Die Casting) tools are printed from this material. To date, only layer thicknesses of 20–50 μm are used, and parameters for 100 µm were an undescribed area, according to the state of the art. Increasing the layer thickness could lead to time reduction and higher economic efficiency. The study methodology was divided into several steps. The first step was the research of the single-track 3D printing parameters for the subsequent development of a more accurate description of process parameters. Then, in the second step, volume samples were produced in two campaigns, whose porosity was evaluated by metallographic and CT (computed tomography) analysis. The main requirement for the process parameters was a relative density of the printed material of at least 99.9%, which was achieved and confirmed using the parameters for the production of the samples for the tensile test. Therefore, the results of this article could serve as a methodological procedure for optimizing the parameters to streamline the 3D printing process, and the developed parameters may be used for the productive and quality 3D printing of 1.2709 tool steel.