bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital manufacturing in laser powder bed fusion of aluminium alloy safety feature for EV battery cell
Authors: Saariluoma Heikki , Vesterinen Kalevi , Salminen Antti 
Published: December 2023

Abstract
Recently, a new way to produce prismatic Li-ion battery cell’s lid part for Battery Electric Vehicles (BEV) was presented, with integrated cell thermal management, based on the Laser Additive Manufacturing (LAM) method. In the solution, the safety vent protects the battery cell from unpredictable explosions caused by the increasing internal pressure. Additive manufacturing allows integrating the feature to the cell lid part and significantly decreases the process steps in manufacturing and increases the production efficiency. Aluminium powder materials for the used Laser Powder Bed Fusion (LPBF) method have relatively high tensile strength, which causes the need for minimum layer thickness for the safety vent. Reliability of producing such a thin layer as a gas tight structure is challenging and several procedures were studied. Material with lower tensile strength and higher elongation ability was tested during the second phase. The challenge is to produce such a thin wall thickness, which breaks at the pressure level of one MPa and opens the valve. The design is based on FEM analysis with constant equivalent strain theory to optimize safety vent dimensions. The pressure test was performed to measure the rupturing pressure of the thin aluminium LPBF layer as materials in normal mode and in annealed mode. The constant equivalent strain theory for estimate rupture pressure was in fine agreement with the experimentally measured ones, even with a maximum error rate. The results show that the manufacturing method is possible for such automotive mass production parts and when comparing different stacking strategies, it showed a great influence in the productivity of such parts’ production.
Development of a build volume reduction kit for studying epitaxial re-solidification in laser powder bed fusion
Authors: Norouzi-Inallu M. , Laitinen V. , Poutiainen I. , Ullakko K. 
Published: December 2023

Abstract
Laser powder bed fusion (PBF-LB/M) is a promising additive manufacturing process that enables the production of complex and high-performance parts. However, the high cost of materials and the need for large quantities of powder in conventional industrial-grade systems pose challenges for experimental materials development and testing activities. This study focuses on the development of a modular build volume reduction kit for an existing EOS EOSINT M-series PBF-LB/M machine. The proposed build volume reduction kit can be customized and adapted for specific research needs, expanding the capabilities of existing infrastructure without significant capital investment. This study describes the design and characterization of the build volume reduction kit and a detachable Pt-heater module, which allows for preheating of the substrate material above 500 °C. The kit’s operation was validated by manufacturing simple cuboid samples using EOS 316L stainless steel powder on a 316L stainless steel substrate. The results demonstrate the feasibility of using the reduction kit for cost-effective experimental investigations, as well as highlighting its potential for studying the epitaxial solidification of PBF-LB/M-built functional materials.
Optimized Inconel 718 pressure vessel manufactured with laser powder bed fusion
Authors: Tepponen V , Westman S , Nyamekye P , Poutiainen I 
Published: December 2023

Abstract
Laser powder bed fusion (L-PBF) is one of the most novel additive manufacturing methods used for a wide range of industrial grade metallic materials. The process can produce end-use metal parts with desirable qualities and mechanical properties. L-PBF however, remains a complicated and expensive manufacturing method. Design for additive manufacturing (DfAM) is a key aspect leveraging the uptake of advantages and possibilities offered by AM in augmenting its competitiveness against conventional manufacturing (CM) methods. Inconel 718 (IN718) is a nickel-based superalloy boasting high temperature strength, good oxidation, and corrosion resistance at elevated temperatures. IN718 is commonly used for high performance applications, such as power and process industry parts, and gas turbine components. High inherent toughness, hardness, work hardening, and low thermal conductivity properties make the material difficult to manufacture through conventional machining methods. The layer-by-layer building of powder metals via L-PBF makes it possible to build different geometrical intricacy. The offered manufacturing flexibility for complex high-end metal structures for variety of applications makes L-PBF an alternative manufacturing method for high performance metals. This study investigates use of DfAM for a small-scale pressure vessel with predefined geometry, dimensions, design space and load condition. The aim is to introduce and exploit contemporary design optimization methods and their feasibility with AM. Structures, such as lattices and stress field driven geometries based on finite element analysis are investigated in this study. The designs are virtually tested under predefined pressure load of 50 bar. All four design options are manufactured on EOS M290 and IN718 powder. The result of the study shows the different optimizations decrease weight and improve material savings without compromising the linear load capacity. Optimized designs could also be made in such a way that it does not increase the manufacturing duration or add additional steps to it.
Validation of powder layering simulation via packing density measurement for laser-based powder bed fusion
Authors: Haapa E , Gopaluni A , Piili H , Ganvir A , Salminen A , Ottelin J 
Published: December 2023

Abstract
Powder bed fusion using a laser beam (PBF-LB/M) is considered one of the most versatile additive manufacturing methods as the parts printed have high resolution thanks to the low layer thickness used. The powder packing density (PD) of the powder layer has a significant impact on the density, surface roughness and other mechanical properties of the built parts. Due to the difficulty of characterizing the powder bed in situ, simulation has often been used to study the powder behavior on the powder bed. However, in order for the simulation to have practical value, there must be some way of confirming the results via experimental methods, also called validation. The aim of this study was to develop a powder packing density-based validation method for a powder bed simulation. The developed method featured a simplistic “open cup” style sample which traps powder inside for PD measurement. The samples were built with an EOS M 290 PBF-LB/M system using Alloy 718 (also known as “IN718” or “Inconel”) powder. Average PD over the five built samples was 52.4 %, with a standard deviation of 0.2 %. The method was used to successfully validate a powder bed simulation with four recoated powder layers, modelled using FLOW-3D DEM simulation software from Flow Science Inc. Similar methods for PD characterization were found in literature, but in many cases the method does not fully correspond to the conditions of a simulated powder bed, the scale is very small, or the reliability of the PD measurement is not confirmed. The method presented in this study corresponds to typical powder bed simulation conditions, while retaining high reliability and repeatability of results.
Bioinert ceramics scaffolds for bone tissue engineering by laser-based powder bed fusion: a preliminary review
Authors: Kamboj N , Piili H , Ganvir A , Gopaluni A , Nayak C , Moritz N , Salminen A 
Published: December 2023

Abstract
The implementation of laser powder bed fusion (PBF-LB) on ceramics is far more demanding than their metallic and polymeric counterparts for bone tissue engineering (BTE). The review will shed light on bioinert ceramics-based biomaterials manufacturing through PBF-LB incorporating alumina and yttria-stabilized zirconia as oxide-based ceramics and nitride-based ceramics as non-oxide-based ceramics with particular prominence on their properties and requirements for biomedical devices and BTE. The review paper will also classify bioinert scaffolds processed through PBF-LB as a medium to manufacture drug delivery systems (DDS) and to ameliorate critical-sized bone defects based on the fracture site length of the bone with the various modes of functionalization through the incorporation of drugs, stem cells, and growth factors for personalized medicine.
Additive manufacturing systems integration
Authors: Heilala J , Parchegani S , Piili H 
Published: December 2023

Abstract
This research explores real-time database systems’ evolution, focusing on unique features and the addressed challenges. It examines the role of multi-material additive manufacturing quality domain databases in innovation and maintaining standards. It also looks at the challenges of implementing quality manufacturing systems from a technology, organization, and people of European Manufacturing research perspective. The study offers a new perspective on reconfigurable intelligent surfaces with multi-material additive manufacturing with system integration, discussing its applications and digital products’ transformative potential. Enhancing multi-material additive manufacturing capabilities redefines the industries, creating a strong communication culture by adopting quality integration of quality and robotics while exploring the future of mathematics complexity in optimizing manufacturing education. The paper also explains the statistical classification of historical technology in manufacturing engineering education by flagging the platform‘s role of opportunities in secure research collaboration. The manufacturing horizontal is essential for effectively managing the multi-material additive manufacturing system through advanced technology to quality management integration. Certified advanced training and competency development econophysics show the multi-material additive manufacturing systems development influence on the production theories and mechanics of complex electronics. To enable, for example, communication links and cellural multi-material additive manufacturing integrations research for new technologies.
Effects of laser welding speed on the microstructure and microhardness of ultra-high strength steel S1100
Authors: Afkhami S , Ghafouri M , Lipiäinen K , Poutiainen I , Amraei M , Björk T 
Published: December 2023

Abstract
Ultra-high strength steels strengthened via thermomechanical processing and low alloying constituents are currently quite popular for industrial applications. The popularity is primarily due to these steels being relatively economical compared with their high-alloy rivals, making them feasible to provide significant strength-to-weight ratios with reasonable costs in steel structures. However, welded joints in most steel structures cannot be avoided, and ultra-high strength steels, due to their thermomechanical strengthening mechanisms, are prone to loss of strength, toughness, or ductility after welding. Also, due to the ultra-high strength levels of the base metals, providing a suitable filler material with mechanical properties comparable to those of the base metals for filling the joint gap seems challenging. Accordingly, laser welding can be a relatively more suitable approach than arc welding to weld ultra-high strength steels, considering its easier control over the weld heat input, joint shape, and the possibility of welding without the requirement of filler metals. Therefore, this study investigates the influence of travel speed and its subsequent change in heat input of laser welding on the joint shape, microstructure, and hardness of the S1100 low-alloy carbon steel, one of the most commonly used ultra-high strength steels in modernized steel structures.
Impact of laser beam shaping on weld pool and seam geometry in butt-joint welding with filler wire
Authors: Mi Y , Sikström F , Nilsen M , Joshi S , Guglielmi P , Palumbo G , Ancona A 
Published: December 2023

Abstract
Beam shaping offers a promising solution to address various challenges in laser-based processes. This study explores the use of an adaptive beam shaping solution using a deformable mirror for high-power continuous wave lasers. Specifically, the impact of three different elliptical beam shapes on weld pool geometry, weld cross section in butt-joint welding with a filler wire is investigated. The results reveal that beam shaping significantly affects the weld pool and cross section, with elliptical beam shapes resulting in wider fusion zones in two tested cases and more uniform weld bead compared to a typical circular beam. These findings highlight the potential of beam shaping for enhancing consistency and quality in laser beam welding.
Influence of shielding gas on filler wire mixing at laser hybrid welding of thick high strength steels
Authors: Üstündag Ömer , Kampffmeyer Dirk , Wolters Michael , Bakir Nasim , Gumenyuk Andrey , Rethmeier Michael 
Published: December 2023

Abstract
The laser hybrid welding process offers many advantages during welding of thick-walled steels, such as the increased penetration depth and, thus, reduced number of layers, reduced heat input and decreased distortion compared to arc-based welding processes. Especially, when welding high-strength steels (HSS), the reduced heat input plays an essential role. However, a major challenge when laser hybrid welding of thick-walled steels is the limited filler wire mixing over the entire seam thickness, which can lead to changed mechanical properties over the depth. To overcome this issue, the add of oxygen into the shielding gas and its influence on the filler wire mixing and finally to the mechanical properties were investigated within this work. Therefore, 20 mm thick S690QL steels were laser hybrid welded in a single-pass. A contactless electromagnetic backing was used to avoid sagging. The admixture of oxygen was performed by a gas mixer, where the oxygen content was varied between 0 % and 7.2 %. The experiments were also accompanied by laser beam welding tests in steel/glass configuration, where the melt pool geometry as well as the melt flow characteristics were captured by a high-speed camera. It can be concluded, that adding of approx. 4 % oxygen into the shielding gas had a positive effect on the filler wire mixing, were up to a depth of 18 mm elements of the filler wire could be observed.
The effects of laser welding parameters on weldability and quality of the microstructure of additively manufactured Inconel 718-316L joints
Authors: Kivirasi E , Lindqvist M , Lipiäinen K , Piili H , Salminen A 
Published: December 2023

Abstract
Additive manufacturing of metals is a way of producing high-quality end-use parts. Technical alloys, for example Inconel 718, can be used to obtain a lot of benefits for example wear, corrosion, and heat resistance. Laser welding of Inconel 718 is a standard process, but there is rather limited amount of information of welding of additively manufactured nickel superalloys to the additively manufactured stainless steel. The process parameters need to be considered in laser welding. Undesired microstructure can occur due to wrong heat input during the welding process. This study examines laser welding of additively manufactured Inconel 718-316L parts and the effects of the welding parameters to the quality of the weld by analysing microstructure from the heat affected zone. This is done to achieve better part quality more cost efficiently compared to traditionally produced parts and to optimize the welding parameters. It is not feasible to manufacture the full large structure with IN718 and AM could be used to manufacture just the functional parts of the assembly. Tests have shown that welding heat input and cooling time affect to the quality. Inconel 718 hardness decrease across the fused zone because of the mixing of different elements in the molten weld pool. Laser welding highlights cuboidal shaped niobium rich carbides throughout the material to the heat affected zone grain boundaries on Inconel side.
Coaxial Wire Laser-based Additive Manufacturing of AA7075 with TiC Nanoparticles
Authors: Meneses W , Tuominen J , Ylä-Autio A , Wiikinkoski O , Sabr A , Peura P 
Published: December 2023

Abstract
AA7075 is a heat treatable aluminium alloy widely used in aerospace and automotive applications due to its outstanding high strength-to-weight ratio. However, the implementation of this alloy in Additive Manufacturing (AM) processes has been limited due to its susceptibility to hot cracking. Moreover, selective evaporation of low boiling point elements Zn and Mg can cause gas porosity and diminish the mechanical properties of AM parts. Recent research revealed the effectiveness of nanoparticles additives to change the solidification behaviour of high-strength aluminium alloys and improve their weldability/printability. In this study, AA7075 enhanced with TiC nanoparticles was utilized as wire feedstock to create single and multi-layer samples with coaxial laser-directed energy deposition (L-DED). The response of the samples to precipitation hardening was studied, evaluating the microstructure and the microhardness before and after T6 heat treatment. Specimens were characterized using optical and electron microscopy and electron backscatter diffraction (EBSD). Crack-free and virtually porosity-free samples were fabricated, which exhibit a refined equiaxed grain structure with grain size <10μm. This confirms the ability of TiC nanoparticles to prevent columnar dendritic growth and promote heterogeneous nucleation. Microhardness values increased by 51 HV after T6 heat treatment and were uniform across the sample. Energy Dispersive Spectroscopy (EDS) analysis showed that there are evaporation losses of Zn and Mg. Considering the boiling temperatures of these elements, it is inferred that the molten pool reaches temperatures above 1090°C, and the partially melted zone temperature is between 907°C and 1090°C.
Temperature and distortion in laser melt injection of MMC wear-resistant coatings in a copper beryllium alloy
Authors: Bohlen A , Langebeck A , Seefeld T 
Published: December 2023

Abstract
Wear-resistant coatings made of MMC materials (metal matrix composites) are ideal for increasing the service life of tools subjected to high abrasive stresses. Such MMC surfaces can be produced by laser melt injection during the manufacturing process of the tools or subsequently as a retrofit near-net-shape. However, during laser melt injection (LMI) thermally induced residual stresses can be introduced into the MMC surfaces. These can have a detrimental effect on the service life of these surfaces and thus reduce the positive effect of wear resistance.
In order to determine the influence hard particles injected during LMI have on residual stresses within the surface layer the distortion of the surface layer was evaluated. MMC layers consisting of a copper beryllium matrix and fused tungsten carbide hard particles were created by LMI. The MMC layers are compared to parts with remelted surfaces. Laser power and process velocity were varied to examine their influence on distortion. The process temperature was recorded on the melt pool by a two-color pyrometer. After the process the top layer of the MMC surface was cut off by wire EDM and then measured with a coordinate measuring machine. It is shown that an increase of incorporated powder mass per unit length and process temperature lead to higher distortions.
The properties of laser-clad coatings made of NiCrBSi alloy and recycled tungsten carbides
Authors: Tuominen J , Näkki J 
Published: December 2023

Abstract
Tungsten carbide hard metals are one of the most known and successful powder metallurgical products used in environments where severe wear conditions prevail. Since tungsten belongs to the list of critical raw materials for the European Union (EU), its recycling is highly desirable. In this paper, recycled tungsten carbide powders fabricated by the zinc-reclaim process where mixed with NiCrBSi matrix and deposited with one-step laser cladding using a coaxial powder feeding on mild steel substrates. Prepared clads were tested in low-stress rubber wheel abrasion tests and compared with clads produced from commercial macrocrystalline (WC) and cast and crushed eutectoid WC/W2C reinforced clads. The results showed that recycled WC induced porosity in clads when produced with ‘production’ laser cladding parameters due to small carbide size resulting in poor wear performance. When laser-clad with lower heat input and productivity, pore-free clads with excellent wear performance were obtained.
A Laser Forming Study on Time and Energy Efficiency
Authors: Nikolov Georgi Nikolaev , Thomsen Anders Noel , Kristiansen Morten 
Published: December 2023

Abstract
Laser forming is a relatively slow process utilizing temperature differences in the material to cause plastic deformation. The process requires dwell time between laser passes to cool down the material, which results in a slow production rate. Not fully cooling the workpiece has been shown to give a higher bend rate per unit of time. This, coupled with the cooling rate at higher temperatures being more pronounced permits examining the efficiency of laser forming while working in different temperature ranges. The presented work experimentally explores different temperature ranges for AISI 304 from 20 to 1300°C using a thermal camera. Therefore, for each temperature range, the workpiece is heated and cooled to a achieve a constant peak temperature. The purpose is to compare the bend rate per unit of time with different temperature ranges and to examine overall time efficiency. Finally, since different power levels are utilized for each temperature range, the total energy used to achieve each bend will also be investigated. The results show that the increased formability and rate of cooling at higher temperatures increase efficiency in terms of total time. While efficiency in terms of the equipment is higher when allowing the workpiece to fully cool.
Correlation of signal feature importance and process parameters in water jet-guided laser cutting
Authors: Richter Roland Axel , Braunmüller Falk , Pandiyan Vigneashwara , Shevchik Sergey , Ivas Toni , Zryd Amédée 
Published: December 2023

Abstract
Laser-based cutting can deliver high accuracy and speed during the process. However, there are still some technical challenges to be solved. First, the process itself requires precise focusing of the laser beam. When using continuous wave (CW)- or pulses in the μs- to ns-range for efficient materials removal, not only the targeted material volume is heated, but also the surrounding material due to heat diffusion. This decreases the quality of the cut. Coupling the light into a water-jet solves both issues: It ensures the delivery of focused light to the target surface, while cooling the affected material during processing. This work proposes a real-time monitoring system of the cutting process by exploiting unique physical phenomena related to the process. The water jet allows both the propagation of laser light towards the target while keeping it focused and the back-propagation of process light through the focusing system. This can be captured using suitable sensors, and saved using a data acquisition system. The acquired data can be used for process characterization using signal processing. In this work we demonstrate the direct correlation between different process parameters and statistical signal features. We show that reducing the signal to a few statistical features both in time and frequency by feature extraction does not reduce the information content, but instead makes it more robust to mis-classification while decreasing the classification time. It also opens up a wide range of future applications not only to process data, but also to control the process more precise.