{"title":"Effect of multi-pass shot peening on the microstructure of LPBF AlSi10Mg alloy","authors":"P Snopiński, T Yu, X Zhang, D Juul Jensen","doi":"10.1088/1757-899x/1310/1/012039","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012039","url":null,"abstract":"In this study, we investigated the effect of multi-pass shot peening (SP) on the microstructural evolution of a Laser Powder Bed Fusion AlSi10Mg alloy. Characterization techniques included optical microscopy, scanning electron microscopy, and electron backscatter diffraction (EBSD). The results revealed that multi-pass SP induces a gradient microstructure with notable alterations in the grain structure extending to a depth of approximately 45 μm. EBSD analysis revealed that the SP treatment induced grain refinement and formation of subgrains (average distances between boundaries vary from 3.6 μm in the un-deformed area to 0.4 μm near the heavily deformed surface area). It is discussed how this refined microstructure following SP may lead to substantial improvements in mechanical properties and fatigue strength, and thus hold promises for increased performance of critical components across various industrial applications.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S Rangaraj, S S I Ahmed, A Davis, P J Withers, A Gholinia
{"title":"Understanding fatigue crack propagation pathways in Additively Manufactured AlSi10Mg","authors":"S Rangaraj, S S I Ahmed, A Davis, P J Withers, A Gholinia","doi":"10.1088/1757-899x/1310/1/012025","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012025","url":null,"abstract":"Alloys produced through additive manufacturing (AM) offer substantial advantages, particularly in controlling material utilisation and precisely manipulating processing parameters, resulting in finely tuned material properties. However, the grain structure of AM material is typically complex, influenced by factors such as solidification dynamics, processing parameters, thermal gradients, and residual stress. Fatigue analysis shows considerable scatter due to entrained defects which limits their use as structural components. In this study, fatigue-failed samples from selective laser melted (SLM) AlSi10Mg alloy, oriented horizontal and vertical to the build direction were analysed to understand crack propagation paths. Here X-ray Computed Tomography (CT) was used to examine internal porosity from which fatigue cracks initiate, complemented by electron backscattered diffraction (EBSD) mapping. This enabled us to recognize the crucial role of the complex grain microstructure in controlling fatigue crack propagation.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Applying lab-based DCT to reveal and quantify the 3D grain structure of a miniature chess rook produced by binder jetting","authors":"J Sun, F Bachmann, J Oddershede, E Lauridsen","doi":"10.1088/1757-899x/1310/1/012029","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012029","url":null,"abstract":"Imaging the 3D grain microstructure of additively manufactured (AM) metal samples non-destructively is key to a better understanding of the material performance. Recent advances of lab-based diffraction contrast tomography (DCT) enable non-destructively mapping the spatial distribution of crystallographic orientations in the bulk of certain types of metal AM parts. Combining these 3D texture measurements with traditional absorption contrast tomography (ACT) gives unprecedented insights into materials structure, such as the spatial distribution of porosities and the relationship between microstructural anisotropies and the build direction. Here, the combination of ACT and DCT is exemplified for a metal AM sample produced by binder jetting. This application highlights some of the recent technical progress enabling 3D mapping of metal AM structures and leads to a discussion of remaining challenges for lab-based DCT in the metal AM field.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Building microstructures by welding millions of little bits of metal together: measurement approaches, model validation, and post-build processing","authors":"L E Levine, E J Schwalbach, F Zhang","doi":"10.1088/1757-899x/1310/1/012011","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012011","url":null,"abstract":"Over the past decade, immense, world-wide research and development efforts have attempted to bring additive manufacturing (AM) of metals into broad industrial use. Although major advances in our understanding and control over metal AM have accrued, its practical application has been underwhelming. The slow pace of commercial adoption can be traced to numerous factors, including poor build reproducibility, sensitivity to heterogeneous local processing conditions during the build, complications in developing and validating suitable processing-structure-property-performance (PSPP) simulation capabilities (physics-based models, surrogate models, and machine learning models), the small number of alloys suitable for metal AM, and the need for developing new alloy-specific post-processing protocols. All these factors negatively impact the purely business decision of what manufacturing approach should be used to produce a given component. Computational materials engineering approaches could play a major role in accelerating the adoption of metal AM, but rigorous model validation will be necessary to make this a reality. Here, discussion will focus on development and deployment of measurement approaches for model validation, and methodologies for accelerating development of post-build heat treatment through thermo-kinetic modelling and in situ measurements.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A convergence study simulating regular waves using the k-ω SST turbulence model in OpenFOAM®","authors":"Xihang Xu, Md Salauddin, Jennifer Keenahan","doi":"10.1088/1757-899x/1312/1/012006","DOIUrl":"https://doi.org/10.1088/1757-899x/1312/1/012006","url":null,"abstract":"OpenFOAM® has been widely used in coastal engineering to visualise and analyse wave-structure interaction and evaluate the effectiveness of innovative coastal protection structures. To study the influence of an eco-retrofitted seawall on the wave overtopping process, a 2D numerical wave tank with a k-ω SST turbulence model is developed to recreate previously completed experiments. Results of wave structure interactions at a plain vertical seawall subjected to regular waves using OpenFOAM® are presented, considering various configurations of time steps and grid resolutions. Both deep water (near the wave maker) and shallow water (near the structure) wave structure interactions are analysed. Results indicate that a finer mesh density is required in shallow water regions compared with deep water regions due to the dynamics of the wave-breaking process in the wave reflection area. Results also indicate that mesh density has a more significant influence than the time step. Overall, this paper showcases the entire process of establishing two-phase flow CFD (computational fluid dynamics) simulations in OpenFOAM® and provides a reference model for future research on studying the effectiveness of eco-retrofitting approaches on wave attenuation.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W E Alphonso, M A Ribeiro, R Rothfelder, M Schmidt, J H Hattel, D Juul Jensen, M Bayat
{"title":"Elucidating the impact of laser beam shape on the as-printed microstructure in 316L stainless steel","authors":"W E Alphonso, M A Ribeiro, R Rothfelder, M Schmidt, J H Hattel, D Juul Jensen, M Bayat","doi":"10.1088/1757-899x/1310/1/012040","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012040","url":null,"abstract":"In Laser Powder Bed Fusion (L-PBF), the intrinsic inclination of the laser beam creates variability in the interaction between the laser and the melt pool, which along with thermal conditions within the pool, results in the formation of defects in the parts. To elucidate the impact of laser beam inclination on the melt pool, a deposition scale model using the finite volume method (FVM) is developed. The laser model demonstrates that as the laser beam inclines towards the periphery of the build plate, the projected laser spot size enlarges, resulting in lowered energy density. To assess how the laser beam inclination affects multi-layer printing, cubic specimens are printed at both the center and the far corner of a rectangular build plate of 280 mm x 280 mm size. X-ray computer tomography (X-CT) is used to investigate internal porosities and electron backscatter diffraction (EBSD) is used to characterize the microstructure of the printed cubes. The experimental results are discussed based on the FVM simulations.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Asmelash Haftu Amaha, Shivasubramanian Gopalakrishnan, Prabhu Ramachandran, Joel Guerrero
{"title":"Vertical axis turbine simulations based on sliding and overset meshes","authors":"Asmelash Haftu Amaha, Shivasubramanian Gopalakrishnan, Prabhu Ramachandran, Joel Guerrero","doi":"10.1088/1757-899x/1312/1/012010","DOIUrl":"https://doi.org/10.1088/1757-899x/1312/1/012010","url":null,"abstract":"Vertical Axis Turbines (VATs) are gaining traction as decentralized energy sources due to their simple design and suitability for various wind conditions. However, understanding VAT aerodynamics requires robust computational methods. This study compares the accuracy and efficiency of two meshing techniques (sliding mesh and overset mesh) for VAT simulations using OpenFOAM. Validation against experimental data confirms the capability of both methods to capture flow physics and predict turbine performance. The results suggest both techniques offer efficient and accurate VAT simulations, providing valuable tools for future VAT optimization and experimental validation.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of print-chamber oxygen content on the microstructure and properties of 3D-printed 316L","authors":"WY Wang, W Liu, A Godfrey","doi":"10.1088/1757-899x/1310/1/012007","DOIUrl":"https://doi.org/10.1088/1757-899x/1310/1/012007","url":null,"abstract":"Samples of 316L stainless steel have been prepared using laser-powder bed fusion from the same batch of powder using different print-chamber oxygen levels, ranging from 50 ppm to 1500 ppm. The oxide particle density is found to increase with oxygen content, while the cell structure is invariant with oxygen level and the grain size shows a relatively sharp transition for measured oxygen levels of above 450 ppm. Based on the microstructural observations it is suggested that the increasing oxygen levels leads to a transition in the solidification pattern. Samples printed at the higher oxygen level show higher strength and lower mechanical anisotropy than samples with a coarser grains structure printed at lower oxygen levels. The main influence of the higher oxide particle content on thermal stability is on the kinetics of recrystallization during isothermal annealing at 1000 °C.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P Zimmermann, A Birkert, P Saup, F Marner, M Häussermann
{"title":"Holistic springback compensation procedure","authors":"P Zimmermann, A Birkert, P Saup, F Marner, M Häussermann","doi":"10.1088/1757-899x/1307/1/012034","DOIUrl":"https://doi.org/10.1088/1757-899x/1307/1/012034","url":null,"abstract":"The elastic springback during the manufacturing process of stamped car body components causes dimensional deviations. To compensate these deviations, the common approach is to modify the tool surfaces in the opposite direction of the deviations – this is called springback compensation. In the procedure of springback compensation various issues must be solved. To achieve the main goal of a dimensionally accurate part, it must be ensured that, on the one hand the distance normal to the sheet surface between the springback part and the target geometry is within a specified dimensional tolerance. On the other hand, it must be ensured that the surface areas and characteristic lengths of the springback part and that of the target geometry match as closely as possible. In the past, approaches/methods, such as the physical compensation method and the physical scaling approach, have been presented which can successfully counteract these problems. Furthermore, in a multi-stage process in subsequent operations a stable part position must be achieved and unwanted plastic deformations must be avoided during blankholder closing. Therefore, different compensation strategies have been presented, which can fulfil these requirements. However, in the publication of these methods, the problems were always considered individually. This paper shows how all the named requirements can be achieved by combining the individual methods in springback compensation.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparison of homogeneous anisotropic hardening models in the case of the direct redrawing of a DP600 steel","authors":"N Gautam, S Yoon, F Barlat, S Thuillier","doi":"10.1088/1757-899x/1307/1/012029","DOIUrl":"https://doi.org/10.1088/1757-899x/1307/1/012029","url":null,"abstract":"The use of DP600, an advanced high strength steel, has gained significant attention in automotive industry, especially for complex structures that require multi-step forming operations, leading to non-linear strain path changes. From a numerical modelling perspective, the use of advanced constitutive equations has enabled a precise representation of a large range of behaviors, encompassing reverse and orthogonal strain path changes. Within this context, this study is dedicated to the numerical simulation of a two-step deep drawing process based on distortional plasticity. Two models developed within the Homogeneous Anisotropic Hardening (HAH) framework are considered. This study presents a comparison of the model predictions, calibrated over the same experimental database, in terms of their ability to predict the strain path changes and mechanical behavior of the material during the forming process. Several outputs like the punch load evolution and the strain field are compared with experimental data.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}