Article
Engineering, Manufacturing
M. Strantza, R. K. Ganeriwala, B. Clausen, T. Q. Phan, L. E. Levine, D. C. Pagan, J. P. C. Ruff, W. E. King, N. S. Johnson, R. M. Martinez, V Anghel, G. Rafailov, D. W. Brown
Summary: This study investigates the effect of laser scan strategy on the three-dimensional residual stress state of L-PBF metallic components. High-energy X-ray diffraction was used to measure residual stress in Ti-6Al-4V bridge components built with different scanning patterns. The observed residual stresses were found to be large, around 1/2 to 3/4 of the yield strength, with higher stresses near the edges of components built with island scan strategies.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
Polina Metalnikov, Ali Arslan Kaya, Guy Ben-Hamu, Dan Eliezer
Summary: This study compared the microstructural changes of Ti-6Al-4V alloy prepared by electron beam melting (EBM) and selective laser melting (SLM) in the presence of hydrogen. It was found that SLM Ti6Al-4V with acicular martensitic structure is more vulnerable to hydrogen-induced phase transformation and damage compared to EBM. Additionally, different hydrogen charging environments led to different microstructural changes in EBM Ti-6Al-4V.
MATERIALS CHARACTERIZATION
(2023)
Article
Engineering, Manufacturing
Mohammadreza Asherloo, Ziheng Wu, Melody H. Delpazir, Eyob Ghebreiesus, Sara Fryzlewicz, Runbo Jiang, Benjamin Gould, Mike Heim, Dave Nelson, Mike Marucci, Muktesh Paliwal, Anthony D. Rollett, Amir Mostafaei
Summary: This study compares the performance of HDH Ti-6Al-4V powders with different size distributions and reveals that a suitable combination of laser power-velocity-hatch spacing can achieve part production with a relative density of > 99.5%. Analysis shows that the lower packing density of coarse powder and high keyhole fluctuation result in higher proportions of porosity within builds during the LB-PBF process.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Ming-Wei Wu, Jhewn-Kuang Chen, Mo-Kai Tsai, Shih-Hao Wang, Pang-Hsin Lai
Summary: The study identified the influence of heat treatment temperature on the preferred orientation of LPBF Ti-6Al-4V alloy. Results showed that the preferred orientation of α phase gradually intensified with increasing heat treatment temperature, aligning mostly with the building direction after 950 degrees C heat treatment.
Article
Materials Science, Multidisciplinary
Andrew Deal, Ian Spinelli, Andrew Chuang, Yan Gao, Thomas Broderick
Summary: The study successfully determined elastic strain and residual stress values in an engineering material using high-resolution EBSD and reference patterns from annealed, recrystallized material. The methodology showed good repeatability and provided insight into the state of individual grains.
MATERIALS CHARACTERIZATION
(2021)
Article
Nanoscience & Nanotechnology
C. Andrews, T. W. Heo, R. Shi, C. Basgul, S. Kurtz, M. J. Matthews, M. L. Taheri
Summary: This research aims to quantify the microscale origins of strain in L-PBF manufactured Ti-6Al-4V, understand the interplay between phase evolution and strain, and examine post-processing strain relief strategies. The study found that macroscale thermal strains decreased with heat treatment time, but lattice distortive strain remained primarily in the alpha grains. The retention of the beta phase significantly changed the strain and dislocation distribution while reducing overall residual strain.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Zackary Snow, Christine Cummings, Edward W. Reutzel, Abdalla Nassar, Kyle Abbot, Paul Guerrier, Shawn Kelly, Simon McKown, Jared Blecher, Ryan Overdorff
Summary: In order to promote the widespread adoption of AM, it is important to understand the factors that contribute to intermittent incidents of low fatigue performance. Through the construction of 150 fatigue coupons and the use of X-ray computed tomography, flaws were identified as the main contributors to poor fatigue performance. The study found that lack-of-fusion flaws in the pre-HIP condition and contaminants at the failure origin were the primary causes of reduced fatigue lifetimes.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Mohammadreza Asherloo, Junghyun Hwang, Ryan Leroux, Ziheng Wu, Kamel Fezzaa, Muktesh Paliwal, Anthony D. Rollett, Amir Mostafaei
Summary: Powder feedstock is a significant cost driver in metal additive manufacturing. Replacing spherical powder with cost-efficient non-spherical powder can reduce feedstock cost by up to 50% and increase interest in adopting additive manufacturing for production and new alloy development. A comprehensive study was conducted on the laser powder bed fusion of hydride-dehydride Ti-6Al-4V powder to understand the relationships between process, microstructure, and properties.
MATERIALS CHARACTERIZATION
(2023)
Article
Chemistry, Physical
Nicholas Derimow, Edwin J. Schwalbach, Jake T. Benzing, Jason P. Killgore, Alexandra B. Artusio-Glimpse, Nikolas Hrabe, Brian J. Simonds
Summary: This work investigates the processing-structure-property relationships in laser-based additive manufacturing of Ti-6Al-4V alloy. The study combines experimental measurements and simulations to analyze the effects of these relationships on phase transformations and material performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Quentin Gaillard, Xavier Boulnat, Sophie Cazottes, Sylvain Dancette, Christophe Desrayaud
Summary: This study explores the relationship between interstitial contents and transition temperatures in as-built Ti-6Al-4V parts manufactured by Laser Powder Bed Fusion. The findings suggest that the martensite in the as-built microstructure can be decomposed into a stable alpha + beta structure at temperatures exceeding 490 degrees C. The oxygen and nitrogen pick-up during the manufacturing process contribute to an elevated beta transus temperature in the as-built parts.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
Chihpin Andrew Chuang, Syed Saahir Shahab Ahmed, Peter Kenesei, Jonathan Almer, Dileep Singh
Summary: The study utilized high-energy x-ray imaging to characterize metal powders, analyzing particle size, shape, and internal defects, revealing structural differences between recycled and as-received powders that help determine the feasibility of recycling powders.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Nanoscience & Nanotechnology
F. R. Kaschel, R. K. Vijayaraghavan, P. J. McNally, D. P. Dowling, M. Celikin
Summary: Thermal heat treatment is commonly used to enhance the mechanical performance of additively manufactured titanium components. Stress relaxation and phase transformation were investigated through isothermal heat treatments and high temperature X-ray Diffraction. Isothermal holding at 400 degrees Celsius increased ultimate tensile strength and yield strength, while treatments between 550 and 700 degrees Celsius promoted martensitic decomposition and decreased ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Mechanics
Bingqing Chen, Zhengkai Wu, Taiqi Yan, Ziang He, Bingbing Sun, Guangping Guo, Shengchuan Wu
Summary: This study investigates the influence of annealing temperature on the tensile properties and fatigue resistance of laser powder bed fused Ti6Al-4V alloys. The relationship between defect size and fatigue limits is established, and a fatigue life prediction model based on a normalized fatigue S-N curve is proposed.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Nanoscience & Nanotechnology
Souvik Sahoo, Anuja Joshi, Vamsi K. Balla, Mitun Das, Shibayan Roy
Summary: In this study, pre-alloyed Ti-6Al-4V powder was deposited on a CP-Titanium substrate using the LENS™ process to achieve optimal adhesion and densification. The resulting microstructure displayed columnar beta grains and thin lamellar (alpha+beta)-colonies, with additional interfaces created due to re-melting between layers. Variations in hardness and COF were observed along different surfaces and directions, indicating potential performance issues in the as-deposited parts.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
Gitanjali Shanbhag, Evan Wheat, Shawn Moylan, Mihaela Vlasea
Summary: Tensile testing is essential for qualifying additive manufacturing builds and materials. The geometry, size, build orientation, and internal porous defects of specimens significantly affect the tensile properties. Horizontally built specimens exhibit higher yield and tensile strengths, but lower elongation, while an increase in cross-sectional area leads to higher strength and modulus.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Mechanical
Tobias Strohmann, Denis Starostin-Penner, Eric Breitbarth, Guillermo Requena
Summary: The occurrence of fatigue cracks is a natural part of engineering structures subjected to nonconstant loads, making accurate description of cracks crucial for safety standards. This study successfully implemented a deep convolutional neural network with digital image correlation to detect crack paths and tips, demonstrating accuracy and effectiveness in experiments. Additionally, incorporating synthetic data from finite element analyses improved the detection accuracy of cracks beyond the range of original training data.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Mariana Poliserpi, Pere Barriobero-Vila, Guillermo Requena, Laura Noel Garcia, Alfredo Tolley, Cecilia Poletti, Tomas Vojtek, Adam Weiser, Norbert Schell, Andreas Stark, Roberto Boeri, Silvana Sommadossi
Summary: This study investigates the microstructure and phase transformation process of IN718/Al/IN718 couples bonded by the Transient Liquid Phase Bonding (TLPB) process at different temperatures, revealing the evolution of the AlNi layer over time and the formation of two distinct layers with varying compositions.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Uwe Zerbst, Mauro Madia, Giovanni Bruno, Kai Hilgenberg
Summary: The paper discusses the challenges of safe fatigue design of metallic components fabricated through additive manufacturing, highlighting issues such as material property inhomogeneity, defects, and residual stresses. Specific solutions are required to identify critical sites and establish fatigue assessment methods for these components.
Article
Chemistry, Multidisciplinary
Margarita A. Khimich, Konstantin A. Prosolov, Tatiana Mishurova, Sergei Evsevleev, Xavier Monforte, Andreas H. Teuschl, Paul Slezak, Egor A. Ibragimov, Alexander A. Saprykin, Zhanna G. Kovalevskaya, Andrey I. Dmitriev, Giovanni Bruno, Yurii P. Sharkeev
Summary: Additive manufacturing of low elastic modulus alloys with a certain level of porosity for biomedical applications is a growing area of research. Porous Ti-Nb alloy samples with open porosity and roughness were manufactured using LPBF, while dense samples had a smooth surface profile. In vitro cell viability tests showed increased cell density on the surface of porous Ti-Nb samples over time, indicating non-cytotoxicity and potential for further in vivo studies.
Article
Chemistry, Physical
Dmitriy Khrapov, Maria Kozadayeva, Kayrat Manabaev, Alexey Panin, William Sjostrom, Andrey Koptyug, Tatiana Mishurova, Sergei Evsevleev, Dietmar Meinel, Giovanni Bruno, David Cheneler, Roman Surmenev, Maria Surmeneva
Summary: Through Electron Beam Melting, Triply Periodic Minimal Surface (TPMS) gyroid sheet-based structures were successfully manufactured for the first time, with inputted zero and 200 μm wall thicknesses. Mechanical properties of the structures under different production Themes were investigated and found to be similar. Finite element simulations demonstrated that gyroids manufactured in different Themes can effectively mimic the mechanical properties of bones.
Article
Chemistry, Physical
Sergei Evsevleev, Tatiana Mishurova, Dmitriy Khrapov, Aleksandra Paveleva, Dietmar Meinel, Roman Surmenev, Maria Surmeneva, Andrey Koptyug, Giovanni Bruno
Summary: This study conducted quantitative non-destructive analysis of TPMSS manufactured from Ti-6Al-4V alloy by electron beam melting using X-ray computed tomography. Different chemical etching strategies were evaluated for their effects on structural elements and surface roughness reduction.
Review
Materials Science, Multidisciplinary
Jakob Schroeder, Alexander Evans, Tatiana Mishurova, Alexander Ulbricht, Maximilian Sprengel, Itziar Serrano-Munoz, Tobias Fritsch, Arne Kromm, Thomas Kannengiesser, Giovanni Bruno
Summary: Residual stresses generated during laser-based additive manufacturing can lead to distortion or cracking of parts, emphasizing the importance of understanding their magnitude and spatial distribution for mitigation strategies. Diffraction-based methods offer a non-destructive way to determine these stresses, while the unique microstructures and textures associated with laser-based additive manufacturing processes present metrological challenges.
Article
Materials Science, Multidisciplinary
Simon Oster, Tobias Fritsch, Alexander Ulbricht, Gunther Mohr, Giovanni Bruno, Christiane Maierhofer, Simon J. Altenburg
Summary: The detection of internal irregularities is crucial for quality assessment in metal-based additive manufacturing. In this study, the registration of thermal imaging and X-ray micro computed tomography datasets is carried out for the development of a porosity prediction model. A novel preprocessing methodology is introduced to deal with the challenging deformations caused by shrinkage and material elevation effects.
Editorial Material
Chemistry, Physical
Giovanni Bruno
Editorial Material
Materials Science, Multidisciplinary
Giovanni Bruno, Christiane Maierhofer
Article
Imaging Science & Photographic Technology
Athanasios Tsamos, Sergei Evsevleev, Rita Fioresi, Francesco Faglioni, Giovanni Bruno
Summary: The greatest challenge in using DCNNs for automatic segmentation of microstructural XCT data is the acquisition of sufficient and relevant training data. This study introduces a method for generating synthetic XCT data for a challenging composite material. The proposed method achieves successful segmentations by using data augmentation, a special deep convolutional neural network, and a multi-view forwarding strategy. An overall Dice score of 0.77 is obtained. The methods presented in this work are applicable to other materials and imaging techniques. Successful segmentation with synthetic data can accelerate scientific output.
JOURNAL OF IMAGING
(2023)
Article
Engineering, Chemical
Jonathan Freund, Miriam Loebbecke, Alexander Delp, Frank Walther, Shuang Wu, Thomas Troester, Jan Haubrich
Summary: This study investigates the pulsed laser surface pretreatment of metal surfaces to improve the mechanical performance and address current shortcomings of adhesive bonds. The results show that the laser parameters power and pulse frequency are critical for obtaining high single-lap shear strengths. The pretreated surfaces with high micro- and nano-surface enlargement and deep solidification structures provide high shear strengths and negligible aging losses.
JOURNAL OF ADHESION
(2023)
Article
Chemistry, Physical
Lorenleyn de la Hoz Alford, Camila Gomes Pecanha de Souza, Sidnei Paciornik, Jose Roberto M. d'Almeida, Brenno Santos Leite, Harold C. Avila, Fabien Leonard, Giovanni Bruno
Summary: Two biopolyol-based foams derived from banana leaves or stems were characterized for their compression mechanical behavior and 3D microstructure. They developed a methodology of image acquisition, processing, and analysis to discriminate the foam cells and measure their numbers, volumes, and shapes. The compression behaviors of the two foams were similar, but the average cell volume was larger for the foam derived from stems. The number of cells increased with compression while the average cell volume decreased. Cell shapes did not change with compression, suggesting the possibility of cell collapse. This study provides insights into the potential use of biopolyol-based foams as green alternatives to petrol-based foams.
Article
Imaging Science & Photographic Technology
Deepak Mani, Andreas Kupsch, Bernd R. Mueller, Giovanni Bruno
Summary: This study evaluates images obtained using diffraction enhanced imaging (DEI) technique and compares the effectiveness of different fitting functions for typical rocking curves (RCs). A robust algorithm is developed to extract meaningful information from each pixel of the image. The potential of the algorithm is demonstrated with two specimens.
JOURNAL OF IMAGING
(2022)
