This page has only limited features, please log in for full access.
This study investigated dry sliding wear properties of AZ31 magnesium alloy and B4C-reinforced AZ31 composites containing 5, 10, and 20 wt.% B4C with bimodal sizes under different loadings (10–80 N) at various sliding speeds (0.1–1 m/s) via the pin-on-disc configuration. Microhardness evaluations showed that when the distribution of B4C particles was uniform the hardness of the composites increased by enhancing the reinforcement content. The unreinforced alloy and the composite samples were examined to determine the wear mechanism maps and identify the dominant wear mechanisms in each wear condition and reinforcement content. For this purpose, wear rates and friction coefficients were recorded during the wear tests and worn surfaces were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry analyses. The determined wear mechanisms were abrasion, oxidation, delamination, adhesion, and plastic deformation as a result of thermal softening and melting. The wear evaluations revealed that the composites containing 5 and 10 wt.% B4C had a significantly higher wear resistance in all the conditions. However, 20 wt.% B4C/AZ31 composite had a lower resistance at high sliding speeds (0.5–1 m/s) and high loadings (40–80 N) in comparison with the unreinforced alloy. The highest wear resistance was obtained at high sliding speeds and low loadings with the domination of oxidative wear.
Seyed Kiomars Moheimani; Azadeh Keshtgar; Saeed Khademzadeh; Morteza Tayebi; Ali Rajaee; Abdollah Saboori. Tribological behaviour of AZ31 magnesium alloy reinforced by bimodal size B4C after precipitation hardening. Journal of Magnesium and Alloys 2021, 1 .
AMA StyleSeyed Kiomars Moheimani, Azadeh Keshtgar, Saeed Khademzadeh, Morteza Tayebi, Ali Rajaee, Abdollah Saboori. Tribological behaviour of AZ31 magnesium alloy reinforced by bimodal size B4C after precipitation hardening. Journal of Magnesium and Alloys. 2021; ():1.
Chicago/Turabian StyleSeyed Kiomars Moheimani; Azadeh Keshtgar; Saeed Khademzadeh; Morteza Tayebi; Ali Rajaee; Abdollah Saboori. 2021. "Tribological behaviour of AZ31 magnesium alloy reinforced by bimodal size B4C after precipitation hardening." Journal of Magnesium and Alloys , no. : 1.
Nowadays, as an emerging technology, additive manufacturing (AM) has received numerous attentions from researchers around the world. The method comprises layer-by-layer manufacturing of products according to the 3D CAD models of the objects. Among other things, AM is capable of producing metal matrix composites (MMCs). Hence, plenty of works in the literature are dedicated to developing different types of MMCs through AM processes. Hence, this paper provides a comprehensive overview on the latest research that has been carried out on the development of the powder-based AM manufactured MMCs from a scientific and technological viewpoint, aimed at highlighting the opportunities and challenges of this innovative manufacturing process. For instance, it is documented that AM is not only able to resolve the reinforcement/matrix bonding issues usually faced with during conventional manufacturing of MMCs, but also it is capable of producing functionally graded composites and geometrically complex objects. Furthermore, it provides the opportunity for a uniform distribution of the reinforcing phase in the metallic matrix and is able to produce composites using refractory metals thanks to the local heat source employed in the method. Despite the aforementioned advantages, there are still some challenges needing more attention from the researchers. Rapid cooling nature of the process, significantly different coefficient of expansion of the matrix and reinforcement, processability, and the lack of suitable parameters and standards for the production of defect-free AM MMCs seem to be among the most important issues to deal with in future works.
Mehran Dadkhah; Mohammad Hossein Mosallanejad; Luca Iuliano; Abdollah Saboori. A Comprehensive Overview on the Latest Progress in the Additive Manufacturing of Metal Matrix Composites: Potential, Challenges, and Feasible Solutions. Acta Metallurgica Sinica (English Letters) 2021, 34, 1173 -1200.
AMA StyleMehran Dadkhah, Mohammad Hossein Mosallanejad, Luca Iuliano, Abdollah Saboori. A Comprehensive Overview on the Latest Progress in the Additive Manufacturing of Metal Matrix Composites: Potential, Challenges, and Feasible Solutions. Acta Metallurgica Sinica (English Letters). 2021; 34 (9):1173-1200.
Chicago/Turabian StyleMehran Dadkhah; Mohammad Hossein Mosallanejad; Luca Iuliano; Abdollah Saboori. 2021. "A Comprehensive Overview on the Latest Progress in the Additive Manufacturing of Metal Matrix Composites: Potential, Challenges, and Feasible Solutions." Acta Metallurgica Sinica (English Letters) 34, no. 9: 1173-1200.
The growing need to develop cost-effective and efficient alloys requires enhancing the flexibility of the current production methods. Additive manufacturing (AM), as an emerging technology, has re-shaped the manufacturing strategies and largely influenced the industrial production lines. The feedstock, the main concern with regard to the powder-based AM methods, are mostly in the form of pre-alloyed powders. Pre-alloyed powders have a narrow composition range, suffer from limited availability and are expensive, making additive manufacturing of new alloys inflexible and costly. A growing number of works in the literature are dedicated to AM in-situ alloying, i.e. employing pure elemental blends as opposed to pre-alloyed ones for producing samples using additive manufacturing. This strategy gives added flexibility to the AM methods by benefiting from the laser local energy and paves the way towards an on-demand alloy design framework that is proportionate to the growing needs of the industry. This review is intended to shed light on the key components of AM in-situ alloying process, from initial blend preparation to requirements for the final composition homogeneity.
Mohammad Hossein Mosallanejad; Behzad Niroumand; Alberta Aversa; Abdollah Saboori. In-situ alloying in laser-based additive manufacturing processes: A critical review. Journal of Alloys and Compounds 2021, 872, 159567 .
AMA StyleMohammad Hossein Mosallanejad, Behzad Niroumand, Alberta Aversa, Abdollah Saboori. In-situ alloying in laser-based additive manufacturing processes: A critical review. Journal of Alloys and Compounds. 2021; 872 ():159567.
Chicago/Turabian StyleMohammad Hossein Mosallanejad; Behzad Niroumand; Alberta Aversa; Abdollah Saboori. 2021. "In-situ alloying in laser-based additive manufacturing processes: A critical review." Journal of Alloys and Compounds 872, no. : 159567.
In the current research, dissimilar friction stir welded (FSW) sheets of AA2198-AA7475 and AA2198-AA6013 were solution treated at 460–580 °C for 1 h. Annealing at 580 °C led to complete degradation of both dissimilar weldments from the AA2198 side. According to the microstructure inspection, solution treatment triggered abnormal grain growth within the stir zone (SZ), and applying higher treatment temperatures enhanced the fraction of transformed grains. SEM analysis revealed that the pre-melting of grain boundaries (GBs) over 540 °C encouraged the diffusion of solute atoms to the GBs. The massive diffusion of Cu to the GBs led to the formation of Cu-rich eutectic phases in AA7475 and AA2198 and dense Cu-rich particles in AA6013. In the meantime, the diffusion of Mg and Zn to the GBs of AA7475 and Fe and Si to the GBs of AA6013 eventuated in the formation of coarse particles at the GBs which, in return, attenuated the bonding adhesion of the grains at SZ. The formation of remarkable Cu-rich phases in the pre-melted regions and significant contraction of the eutectic phase while cooling as well as the formation of particles at GBs resulted in intergranular failure of the joints from the AA2198 side of the SZ.
Mohammad Jandaghi; Hesam Pouraliakbar; Abdollah Saboori; Sun Hong; Matteo Pavese. Comparative Insight into the Interfacial Phase Evolutions during Solution Treatment of Dissimilar Friction Stir Welded AA2198-AA7475 and AA2198-AA6013 Aluminum Sheets. Materials 2021, 14, 1290 .
AMA StyleMohammad Jandaghi, Hesam Pouraliakbar, Abdollah Saboori, Sun Hong, Matteo Pavese. Comparative Insight into the Interfacial Phase Evolutions during Solution Treatment of Dissimilar Friction Stir Welded AA2198-AA7475 and AA2198-AA6013 Aluminum Sheets. Materials. 2021; 14 (5):1290.
Chicago/Turabian StyleMohammad Jandaghi; Hesam Pouraliakbar; Abdollah Saboori; Sun Hong; Matteo Pavese. 2021. "Comparative Insight into the Interfacial Phase Evolutions during Solution Treatment of Dissimilar Friction Stir Welded AA2198-AA7475 and AA2198-AA6013 Aluminum Sheets." Materials 14, no. 5: 1290.
Additive Manufacturing processes are considered advanced manufacturing methods. It would be possible to produce complex shape components from a Computer-Aided Design model in a layer-by-layer manner. Lattice structures as one of the complex geometries could attract lots of attention for both medical and industrial applications. In these structures, besides cell size and cell type, the microstructure of lattice structures can play a key role in these structures' mechanical performance. On the other hand, heat treatment has a significant influence on the mechanical properties of the material. Therefore, in this work, the effect of the heat treatments on the microstructure and mechanical behaviour of Ti-6Al-4V lattice structures manufactured by EBM was analyzed. The main mechanical properties were compared with the Ashby and Gibson model. It is very interesting to notice that a more homogeneous failure mode was found for the heat-treated samples. The structures' relative density was the main factor influencing their mechanical performance of the heat-treated samples. It is also found that the heat treatments were able to preserve the stiffness and the compressive strength of the lattice structures. Besides, an increment of both the elongation at failure and the absorbed energy was obtained after the heat treatments. Microstructure analysis of the heat-treated samples confirms the increment of ductility of the heat-treated samples with respect to the as-built one.
Giuseppe Del Guercio; Manuela Galati; Abdollah Saboori. Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties. 2021, 1 .
AMA StyleGiuseppe Del Guercio, Manuela Galati, Abdollah Saboori. Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties. . 2021; ():1.
Chicago/Turabian StyleGiuseppe Del Guercio; Manuela Galati; Abdollah Saboori. 2021. "Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties." , no. : 1.
Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.
Seyed Kiomars Moheimani; Mehran Dadkhah; Mohammad Hossein Mosallanejad; Abdollah Saboori. Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites. Metals 2021, 11, 125 .
AMA StyleSeyed Kiomars Moheimani, Mehran Dadkhah, Mohammad Hossein Mosallanejad, Abdollah Saboori. Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites. Metals. 2021; 11 (1):125.
Chicago/Turabian StyleSeyed Kiomars Moheimani; Mehran Dadkhah; Mohammad Hossein Mosallanejad; Abdollah Saboori. 2021. "Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites." Metals 11, no. 1: 125.
This work aims to investigate the effect of the process parameters on the densification and microstructure of Inconel 939 (IN939) alloy processed by laser powder bed fusion (LPBF). IN939 is a Ni-based superalloy with high creep and corrosion resistance that can be used up to around 850 °C under load, resulting in higher operative temperatures than the ones commonly allowed for Inconel 718 and Inconel 625 alloys (around 650 °C). However, this alloy can suffer from poor weldability involving possible crack formation. In order to minimize the residual porosity and the cracking density, specific process parameters were investigated. The parameters to generate IN939 samples almost pores-free (porosity ≤0.22%) with a cracking density ≤1.36 mm/mm2 as well as samples almost crack-free (≤0.10 mm/mm2) with limited residual porosity (≤0.89%) were determined. The microstructure revealed fine dendritic/cellular structures with the formation of sub-micrometric phases. A high concentration of these phases was also found along the intergranular cracks, suggesting that their presence, coupled to the high thermal stresses, can be the primary reason for crack formation during the LPBF process.
Giulio Marchese; Simone Parizia; Abdollah Saboori; Diego Manfredi; Mariangela Lombardi; Paolo Fino; Daniele Ugues; Sara Biamino. The Influence of the Process Parameters on the Densification and Microstructure Development of Laser Powder Bed Fused Inconel 939. Metals 2020, 10, 882 .
AMA StyleGiulio Marchese, Simone Parizia, Abdollah Saboori, Diego Manfredi, Mariangela Lombardi, Paolo Fino, Daniele Ugues, Sara Biamino. The Influence of the Process Parameters on the Densification and Microstructure Development of Laser Powder Bed Fused Inconel 939. Metals. 2020; 10 (7):882.
Chicago/Turabian StyleGiulio Marchese; Simone Parizia; Abdollah Saboori; Diego Manfredi; Mariangela Lombardi; Paolo Fino; Daniele Ugues; Sara Biamino. 2020. "The Influence of the Process Parameters on the Densification and Microstructure Development of Laser Powder Bed Fused Inconel 939." Metals 10, no. 7: 882.
The hot working behaviour of additively manufactured Ti–6Al–4V pre-forms by Electron Beam Melting (EBM) has been studied at temperatures of 1000–1200 °C and strain rates of 0.001–1 s−1. As a reference, a wrought Ti–6Al–4V alloy was also analyzed as same as the EBM one. In order to investigate the hot working behaviour of these samples, all the data evaluations were carried out step by step, and the stepwise procedure was discussed. No localized strain as a consequence of shear band formation was found in the samples after the hot compression. The flow stress curves of all the samples showed peak stress at low strains, followed by a regime of flow softening with a near-steady-state flow at large strains. Interestingly, it is found that the initial microstructure and porosity content as well as the chemistry of material (e.g. oxygen content) as being possible contributors to the lower level of flow stress that could be beneficial from the industrial point of view. The flow softening mechanism(s) were discussed in detail using the microstructure of the specimens before and after the hot deformation. Dynamic Recrystalization (DRX) could also explain the gentle oscillation in the appearance of the flow softening curves of the EBM samples. Moreover, the hot working analysis indicated that the activation energy for hot deformation of as-built EBM Ti–6Al–4V alloy was calculated as ~193.25 kJ/mol, which was much lower than the wrought alloy (229.34 kJ/mol). These findings can shed lights on a new integration of metal Additive Manufacturing (AM) and thermomechanical processing. It is very interesting to highlight that through this new integration, it would be possible to reduce the forging steps and save more energy and materials with respect to the conventional routes.
Abdollah Saboori; Ata Abdi; Seyed Ali Fatemi; Giulio Marchese; Sara Biamino; Hamed Mirzadeh. Hot deformation behavior and flow stress modeling of Ti–6Al–4V alloy produced via electron beam melting additive manufacturing technology in single β-phase field. Materials Science and Engineering: A 2020, 792, 139822 .
AMA StyleAbdollah Saboori, Ata Abdi, Seyed Ali Fatemi, Giulio Marchese, Sara Biamino, Hamed Mirzadeh. Hot deformation behavior and flow stress modeling of Ti–6Al–4V alloy produced via electron beam melting additive manufacturing technology in single β-phase field. Materials Science and Engineering: A. 2020; 792 ():139822.
Chicago/Turabian StyleAbdollah Saboori; Ata Abdi; Seyed Ali Fatemi; Giulio Marchese; Sara Biamino; Hamed Mirzadeh. 2020. "Hot deformation behavior and flow stress modeling of Ti–6Al–4V alloy produced via electron beam melting additive manufacturing technology in single β-phase field." Materials Science and Engineering: A 792, no. : 139822.
Additive manufacturing (AM) processes allow producing the complex components in a layerwise fashion. The complexity includes the design of lighter and stronger components by using lattice structures that can be quickly realized through AM technologies. However, the mechanical behaviour of lattice structures is not completely known, especially in the post-treated state. Thus, this work aims to explore the effect of post-treatment on the compressive strength of specimens with lattice structures. The samples are produced using Ti-6Al-4V powder processed by Electron Beam Melting (EBM). The outcomes of this work confirm the correlation between the heat treatment and final mechanical properties.
Manuela Galati; Abdollah Saboori; Sara Biamino; Flaviana Calignano; Mariangela Lombardi; Giovanni Marchiandi; Paolo Minetola; Paolo Fino; Luca Iuliano. Ti-6Al-4V lattice structures produced by EBM: Heat treatment and mechanical properties. Procedia CIRP 2020, 88, 411 -416.
AMA StyleManuela Galati, Abdollah Saboori, Sara Biamino, Flaviana Calignano, Mariangela Lombardi, Giovanni Marchiandi, Paolo Minetola, Paolo Fino, Luca Iuliano. Ti-6Al-4V lattice structures produced by EBM: Heat treatment and mechanical properties. Procedia CIRP. 2020; 88 ():411-416.
Chicago/Turabian StyleManuela Galati; Abdollah Saboori; Sara Biamino; Flaviana Calignano; Mariangela Lombardi; Giovanni Marchiandi; Paolo Minetola; Paolo Fino; Luca Iuliano. 2020. "Ti-6Al-4V lattice structures produced by EBM: Heat treatment and mechanical properties." Procedia CIRP 88, no. : 411-416.
Additive manufacturing processes allow producing complex geometries which include structures with enhanced mechanical performance and biomimetic properties. Among these structures, the interests on the use of lattice are increasing for both medical and mechanical applications. The mechanical behaviour of the structure is closely correlated to its shape and dimension. However, up to now, far too little attention has been paid to this aspect. Hence, this work aims to explore the effect of geometry, dimension and relative density of the cell structure on the compressive strength of specimens with lattice structures. For this purpose, various Lattice structures are designed with different geometries and dimensions. This approach leads to having structures with different relativity densities. Replicas of the designed structure are produced using Ti–6Al–4V powder processed by electron beam melting process. The samples are tested under compression. A new approach to calculate the absorbed energy up to failure by the lattice structure is presented. The results show a close relationship between the mechanical performance of the structure and the investigated parameters. In contrast with the current literature, the presented experimental data and a collection of the literature data highlight that the lattice structures with similar relative density do not exhibit the same Young’s modulus values.
Giuseppe Del Guercio; Manuela Galati; Abdollah Saboori. Innovative Approach to Evaluate the Mechanical Performance of Ti–6Al–4V Lattice Structures Produced by Electron Beam Melting Process. Metals and Materials International 2020, 27, 55 -67.
AMA StyleGiuseppe Del Guercio, Manuela Galati, Abdollah Saboori. Innovative Approach to Evaluate the Mechanical Performance of Ti–6Al–4V Lattice Structures Produced by Electron Beam Melting Process. Metals and Materials International. 2020; 27 (1):55-67.
Chicago/Turabian StyleGiuseppe Del Guercio; Manuela Galati; Abdollah Saboori. 2020. "Innovative Approach to Evaluate the Mechanical Performance of Ti–6Al–4V Lattice Structures Produced by Electron Beam Melting Process." Metals and Materials International 27, no. 1: 55-67.
In this study, the microstructural evolutions and corrosion resistance of aluminium/copper joint fabricated through explosive welding process have been thoroughly investigated, while stand-off distance was variable. Microstructural analyses demonstrate that, regardless of grain refinement in the welding boundary, increasing the stand-off space is followed by a higher thickness of the localized melting pool. X-Ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS) analyses recognized the binary intermetallic layers as a combination of Al2Cu and AlCu. Polarization and electrochemical impedance spectroscopy (EIS) corrosion tests revealed that a higher stand-off distance resulted in the increment of corrosion potential, current rate, and concentration gradient at the interface owing to the remarkable kinetic energy of the collision, which impaired corrosion resistance.
Mohammad Reza Jandaghi; Abdollah Saboori; Gholamreza Khalaj; Mohammadreza Khanzadeh Ghareh Shiran. Microstructural Evolutions and its Impact on the Corrosion Behaviour of Explosively Welded Al/Cu Bimetal. Metals 2020, 10, 634 .
AMA StyleMohammad Reza Jandaghi, Abdollah Saboori, Gholamreza Khalaj, Mohammadreza Khanzadeh Ghareh Shiran. Microstructural Evolutions and its Impact on the Corrosion Behaviour of Explosively Welded Al/Cu Bimetal. Metals. 2020; 10 (5):634.
Chicago/Turabian StyleMohammad Reza Jandaghi; Abdollah Saboori; Gholamreza Khalaj; Mohammadreza Khanzadeh Ghareh Shiran. 2020. "Microstructural Evolutions and its Impact on the Corrosion Behaviour of Explosively Welded Al/Cu Bimetal." Metals 10, no. 5: 634.
Directed energy deposition (DED) as a metal additive manufacturing technology can be used to produce or repair complex shape parts in a layer-wise process using powder or wire. Thanks to its advantages in the fabrication of net-shape and functionally graded components, DED could attract significant interest in the production of high-value parts for different engineering applications. Nevertheless, the industrialization of this technology remains challenging, mainly because of the lack of knowledge regarding the microstructure and mechanical characteristics of as-built parts, as well as the trustworthiness/durability of engineering parts produced by the DED process. Hence, this paper reviews the published data about the microstructure and mechanical performance of DED AISI 316L stainless steel. The data show that building conditions play key roles in the determination of the microstructure and mechanical characteristics of the final components produced via DED. Moreover, this review article sheds light on the major advancements and challenges in the production of AISI 316L parts by the DED process. In addition, it is found that in spite of different investigations carried out on the optimization of process parameters, further research efforts into the production of AISI 316L components via DED technology is required.
Abdollah Saboori; Alberta Aversa; Giulio Marchese; Sara Biamino; Mariangela Lombardi; Paolo Fino. Microstructure and Mechanical Properties of AISI 316L Produced by Directed Energy Deposition-Based Additive Manufacturing: A Review. Applied Sciences 2020, 10, 3310 .
AMA StyleAbdollah Saboori, Alberta Aversa, Giulio Marchese, Sara Biamino, Mariangela Lombardi, Paolo Fino. Microstructure and Mechanical Properties of AISI 316L Produced by Directed Energy Deposition-Based Additive Manufacturing: A Review. Applied Sciences. 2020; 10 (9):3310.
Chicago/Turabian StyleAbdollah Saboori; Alberta Aversa; Giulio Marchese; Sara Biamino; Mariangela Lombardi; Paolo Fino. 2020. "Microstructure and Mechanical Properties of AISI 316L Produced by Directed Energy Deposition-Based Additive Manufacturing: A Review." Applied Sciences 10, no. 9: 3310.
Laser-Directed Energy Deposition was used to produce AISI 316 L stainless steel samples. The effect of the protective atmosphere on the microstructure and mechanical performance of AISI 316 L deposited parts was investigated by building samples using a simple nitrogen shielding gas or using a nitrogen-filled build chamber. The effect of the different processing conditions on the microstructure was evaluated by X-ray analysis, optical and scanning electron microscopy. Only slight differences in the cellular dendrites morphology of samples built under different protective atmosphere conditions were observed. However, the presence of oxides was monitored too: the oxides composition and area fraction were analysed and compared by image analyses, and it was demonstrated that the protective atmosphere mainly affects the oxides dimensions. The effect of the oxides and nitrogen pick-up on the mechanical performance of the samples was evaluated by tensile tests. The results revealed that the nitrogen-filled build chamber allowed the achievement of slightly higher tensile strength and elongation with respect to the other processing conditions as a consequence of the reduced size of the oxide inclusions.
Alberta Aversa; Abdollah Saboori; Erica Librera; Michele de Chirico; Sara Biamino; Mariangela Lombardi; Paolo Fino. The role of Directed Energy Deposition atmosphere mode on the microstructure and mechanical properties of 316L samples. Additive Manufacturing 2020, 34, 101274 .
AMA StyleAlberta Aversa, Abdollah Saboori, Erica Librera, Michele de Chirico, Sara Biamino, Mariangela Lombardi, Paolo Fino. The role of Directed Energy Deposition atmosphere mode on the microstructure and mechanical properties of 316L samples. Additive Manufacturing. 2020; 34 ():101274.
Chicago/Turabian StyleAlberta Aversa; Abdollah Saboori; Erica Librera; Michele de Chirico; Sara Biamino; Mariangela Lombardi; Paolo Fino. 2020. "The role of Directed Energy Deposition atmosphere mode on the microstructure and mechanical properties of 316L samples." Additive Manufacturing 34, no. : 101274.
In this work, 316L cubes were produced by Directed Energy Deposition (DED) process. To evaluate the effect of deposition patterns on the microstructure, mechanical performance and residual stress of 316L samples, two different deposition strategies are selected (67° and 90°). The general microstructure is revealed, and then the effect of deposition pattern on the microstructure of 316L alloy is evaluated through the Primary Cellular Arm Spacing (PCAS) analysis. The cooling rate in each sample is estimated according to the PCAS values. Interestingly, it is found that by increasing the rotation angle per layer, the PCAS value decreases as a consequence of increment in the cooling rate. On the other hand, in both cases, by increasing the distance from the substrate, due to the changes in cooling mechanisms, the cooling rate at first decreases and then at the last layers increases again. The phase composition analysis of 316L samples confirms the predictions that suggested the presence of residual δ-ferrite in the final microstructure. In fact, the final microstructure of samples is characterized by austenitic dendrites together with some residual δ-ferrite in the interdendritic regions. Moreover, the microstructural evaluations exhibit that during the DED process, some metallic inclusions are formed within the 316L samples that consequently deteriorates their mechanical properties. Tensile results show that the samples with 90° rotation per layer have a better mechanical performance such as slightly higher ultimate tensile strength and almost 35% higher elongation to fracture, mainly owing to their finer microstructure and slightly less oxide content. However, in both cases, the elongation of the 316L samples is lower than the typical elongation of this material produced via DED. This discrepancy is found to be as a result of higher inclusions contents in the samples produced in this work with respect to those of literature. Lastly, it is found that the residual stresses on the top surfaces are similar for both deposition patterns, although higher stress values are observed on the lateral surfaces of the cubes produce using the 90° rotation per layer.
Abdollah Saboori; Gabriele Piscopo; Manuel Lai; Alessandro Salmi; Sara Biamino. An investigation on the effect of deposition pattern on the microstructure, mechanical properties and residual stress of 316L produced by Directed Energy Deposition. Materials Science and Engineering: A 2020, 780, 139179 .
AMA StyleAbdollah Saboori, Gabriele Piscopo, Manuel Lai, Alessandro Salmi, Sara Biamino. An investigation on the effect of deposition pattern on the microstructure, mechanical properties and residual stress of 316L produced by Directed Energy Deposition. Materials Science and Engineering: A. 2020; 780 ():139179.
Chicago/Turabian StyleAbdollah Saboori; Gabriele Piscopo; Manuel Lai; Alessandro Salmi; Sara Biamino. 2020. "An investigation on the effect of deposition pattern on the microstructure, mechanical properties and residual stress of 316L produced by Directed Energy Deposition." Materials Science and Engineering: A 780, no. : 139179.
Electron beam melting (EBM) process is an additive manufacturing process largely used to produce complex metallic components made of high-performance materials for aerospace and medical applications. Especially, lattice structures made by Ti–6Al–4V have represented a hot topic for the industrial sectors because of having a great potential to combine lower weights and higher performances that can also be tailored by subsequent heat treatments. However, the little knowledge about the mechanical behaviour of the lattice structures is limiting their applications. The present work aims to provide a comprehensive review of the studies on the mechanical behaviour of the lattice structures made of Ti–6Al–4V. The main steps to produce an EBM part were considered as guidelines to review the literature on the lattice performance: (1) design, (2) process and (3) post-heat treatment. Thereafter, the correlation between the geometrical features of the lattice structure and their mechanical behaviour is discussed. In addition, the correlation among the mechanical performance of the lattice structures and the process precision, surface roughness and working temperature are also reviewed. An investigation on the studies about the properties of heat-treated lattice structure is also conducted.
Giuseppe Del Guercio; Manuela Galati; Abdollah Saboori; Paolo Fino; Luca Iuliano. Microstructure and Mechanical Performance of Ti–6Al–4V Lattice Structures Manufactured via Electron Beam Melting (EBM): A Review. Acta Metallurgica Sinica (English Letters) 2020, 33, 183 -203.
AMA StyleGiuseppe Del Guercio, Manuela Galati, Abdollah Saboori, Paolo Fino, Luca Iuliano. Microstructure and Mechanical Performance of Ti–6Al–4V Lattice Structures Manufactured via Electron Beam Melting (EBM): A Review. Acta Metallurgica Sinica (English Letters). 2020; 33 (2):183-203.
Chicago/Turabian StyleGiuseppe Del Guercio; Manuela Galati; Abdollah Saboori; Paolo Fino; Luca Iuliano. 2020. "Microstructure and Mechanical Performance of Ti–6Al–4V Lattice Structures Manufactured via Electron Beam Melting (EBM): A Review." Acta Metallurgica Sinica (English Letters) 33, no. 2: 183-203.
Directed energy deposition (DED) process is recognized as an alternative technology to produce the complex-shape AISI 316L components. The critical production step in this technology is the optimization of process parameters that can directly affect the final properties of the components. To optimize the process parameters, the residual defects of specimens produced with different combinations of process parameters are evaluated, and the optimum condition is chosen. Therefore, the residual defects assessment is a vital step in finding the optimum process parameters; therefore, this evaluation should be carried out carefully. One of the main issues in the production of AISI 316L by DED process is oxidation during the process that should be considered besides the other defects such as porosity and cracks. However, the identification between the oxides and porosities is not an easy task, and so this study aims to provide more clear insight into the evaluation of pores and oxides in DED 316L samples. The outcomes of this work show that at the best process parameters suitable for a porosity-free sample, there are some oxides that can be misinterpreted as porosity and consequently deteriorate the mechanical properties of the dense sample.
Abdollah Saboori; Mostafa Toushekhah; Alberta Aversa; Manuel Lai; Mariangela Lombardi; Sara Biamino; Paolo Fino. Critical Features in the Microstructural Analysis of AISI 316L Produced By Metal Additive Manufacturing. Metallography, Microstructure, and Analysis 2020, 9, 92 -96.
AMA StyleAbdollah Saboori, Mostafa Toushekhah, Alberta Aversa, Manuel Lai, Mariangela Lombardi, Sara Biamino, Paolo Fino. Critical Features in the Microstructural Analysis of AISI 316L Produced By Metal Additive Manufacturing. Metallography, Microstructure, and Analysis. 2020; 9 (1):92-96.
Chicago/Turabian StyleAbdollah Saboori; Mostafa Toushekhah; Alberta Aversa; Manuel Lai; Mariangela Lombardi; Sara Biamino; Paolo Fino. 2020. "Critical Features in the Microstructural Analysis of AISI 316L Produced By Metal Additive Manufacturing." Metallography, Microstructure, and Analysis 9, no. 1: 92-96.
Miren Aristizabal; P. Jamshidi; Abdollah Saboori; S.C. Cox; Moataz Attallah. Laser powder bed fusion of a Zr-alloy: Tensile properties and biocompatibility. Materials Letters 2020, 259, 1 .
AMA StyleMiren Aristizabal, P. Jamshidi, Abdollah Saboori, S.C. Cox, Moataz Attallah. Laser powder bed fusion of a Zr-alloy: Tensile properties and biocompatibility. Materials Letters. 2020; 259 ():1.
Chicago/Turabian StyleMiren Aristizabal; P. Jamshidi; Abdollah Saboori; S.C. Cox; Moataz Attallah. 2020. "Laser powder bed fusion of a Zr-alloy: Tensile properties and biocompatibility." Materials Letters 259, no. : 1.
Residual stresses (RS) of great magnitude are usually present in parts produced by Laser Powder Bed Fusion (PBF-LB), mainly owing to the extreme temperature gradients and high cooling rates involved in the process. Those “hidden” stresses can be detrimental to a part’s mechanical properties and fatigue life; therefore, it is crucial to know their magnitude and orientation. The hole-drilling strain-gage method was used to determine the RS magnitude and direction-depth profiles. Cuboid specimens in the as-built state, and after standard solution annealing and ageing heat treatment conditions, were prepared to study the RS evolution throughout the heat treatment stages. Measurements were performed on the top and lateral surfaces. In the as-built specimens, tensile stresses of ~400 MPa on the top and above 600 MPa on the lateral surface were obtained. On the lateral surface, RS anisotropy was noticed, with the horizontally aligned stresses being three times lower than the vertically aligned. RS decreased markedly after the first heat treatment. On heat-treated specimens, magnitude oscillations were observed. By microstructure analysis, the presence of carbides was verified, which is a probable root for the oscillations. Furthermore, compressive stresses immediate to the surface were obtained in heat-treated specimens, which is not in agreement with the typical characteristics of parts fabricated by PBF-LB, i.e., tensile stresses at the surface and compressive stresses in the part’s core.
Rafael Barros; Francisco J. G. Silva; Ronny M. Gouveia; Abdollah Saboori; Giulio Marchese; Sara Biamino; Alessandro Salmi; Eleonora Atzeni. Laser Powder Bed Fusion of Inconel 718: Residual Stress Analysis Before and After Heat Treatment. Metals 2019, 9, 1290 .
AMA StyleRafael Barros, Francisco J. G. Silva, Ronny M. Gouveia, Abdollah Saboori, Giulio Marchese, Sara Biamino, Alessandro Salmi, Eleonora Atzeni. Laser Powder Bed Fusion of Inconel 718: Residual Stress Analysis Before and After Heat Treatment. Metals. 2019; 9 (12):1290.
Chicago/Turabian StyleRafael Barros; Francisco J. G. Silva; Ronny M. Gouveia; Abdollah Saboori; Giulio Marchese; Sara Biamino; Alessandro Salmi; Eleonora Atzeni. 2019. "Laser Powder Bed Fusion of Inconel 718: Residual Stress Analysis Before and After Heat Treatment." Metals 9, no. 12: 1290.
There has been growing interest in developing new materials with higher strength-to-weight ratios. Therefore, AM60 magnesium alloy reinforced with SiO2 nanoparticles was synthesized using ultrasound-casting method for the first time, in this study. We introduced 1 and 2 wt.% of SiO2 nanoparticles into the samples. Introduction of nanoparticles led to the grain size drop in MS2 (AM60 + 2 wt.% SiO2) samples. In addition, this increased the hardness of samples from 34.8 Vickers hardness (HV) in M (AM60) to 51.5 HV in MS2, and increased the compressive strength of MS2. Improvement of the mechanical properties can be attributed to a combination of Orowan, Hall–Petch and load-bearing mechanisms. However, ductility of the composites decreased with fracture strains being 0.41, 0.39 and 0.37, respectively, for samples M, MS1 and MS2. Fracture surfaces showed shear fracture in both composite samples with microcracks and a more brittle fracture in MS2.
Farzan Barati; Mojtaba Latifi; Ehsan Moayeri Far; Mohammad Hossein Mosallanejad; Abdollah Saboori. Novel AM60-SiO2 Nanocomposite Produced via Ultrasound-Assisted Casting; Production and Characterization. Materials 2019, 12, 3976 .
AMA StyleFarzan Barati, Mojtaba Latifi, Ehsan Moayeri Far, Mohammad Hossein Mosallanejad, Abdollah Saboori. Novel AM60-SiO2 Nanocomposite Produced via Ultrasound-Assisted Casting; Production and Characterization. Materials. 2019; 12 (23):3976.
Chicago/Turabian StyleFarzan Barati; Mojtaba Latifi; Ehsan Moayeri Far; Mohammad Hossein Mosallanejad; Abdollah Saboori. 2019. "Novel AM60-SiO2 Nanocomposite Produced via Ultrasound-Assisted Casting; Production and Characterization." Materials 12, no. 23: 3976.
Inconel 625 (IN625) alloy has high-temperature strength coupled with high oxidation and corrosion resistance. Additionally, due to its excellent weldability, IN625 can be processed by laser powder bed fusion (LPBF) additive manufacturing (AM) process allowing the production of complex shapes. However, post-AM heat treatment is necessary to develop the desired microstructure and mechanical properties to meet industrial needs. This work is focused on the influence of different heat treatment processes, namely stress relieving, recrystallization annealing and solution annealing on the microstructure and tensile properties of LPBF IN625 alloy. Investigation of the crystallographic texture by electron backscattered diffraction indicated that heat treatments at 1080 °C and 1150 °C tend to eliminate anisotropy in the material by the recrystallization and grain growth resulting in the formation of equiaxed grains. Tensile properties of heat-treated LPBF IN625 alloy built along different orientations revealed higher tensile properties than the minimum recommended values of wrought IN625 alloy in the annealed and solution annealed states.
Giulio Marchese; Simone Parizia; Masoud Rashidi; Abdollah Saboori; Diego Manfredi; Daniele Ugues; Mariangela Lombardi; Eduard Hryha; Sara Biamino. The role of texturing and microstructure evolution on the tensile behavior of heat-treated Inconel 625 produced via laser powder bed fusion. Materials Science and Engineering: A 2019, 769, 138500 .
AMA StyleGiulio Marchese, Simone Parizia, Masoud Rashidi, Abdollah Saboori, Diego Manfredi, Daniele Ugues, Mariangela Lombardi, Eduard Hryha, Sara Biamino. The role of texturing and microstructure evolution on the tensile behavior of heat-treated Inconel 625 produced via laser powder bed fusion. Materials Science and Engineering: A. 2019; 769 ():138500.
Chicago/Turabian StyleGiulio Marchese; Simone Parizia; Masoud Rashidi; Abdollah Saboori; Diego Manfredi; Daniele Ugues; Mariangela Lombardi; Eduard Hryha; Sara Biamino. 2019. "The role of texturing and microstructure evolution on the tensile behavior of heat-treated Inconel 625 produced via laser powder bed fusion." Materials Science and Engineering: A 769, no. : 138500.