Papers by Davide Mombelli
Journal of sustainable metallurgy, May 1, 2024
Journal of Materials Research and Technology
Structural Durability & Health Monitoring, 2013
The definition of a complex operative scenario like ballistic damage, that introduces large strai... more The definition of a complex operative scenario like ballistic damage, that introduces large strains and failure, is a current challenge in the design of critical mechanical components. Aerospace, automotive and manufacturing industries have recently increased their interest in numerical simulations with the long term aim to make these approaches not only reliable enough to reproduce the experimental results but also to provide a trustworthy and effective tool for design. To achieve this aim, the knowledge and calibration of material behaviour is required. Starting from a previous characterization of the constitutive law and ductile failure criterion of Al 6061-T6 aluminium alloy, the present paper evaluates the effects produced by the impact of a bullet on an Al 6061-T6 helicopter transmission rotor shaft. Particular attention is paid to the crystallographic complex texture modifications in microstructural patterns, generated by the ballistic impact. These modifications have been measured on actual damaged specimen, analyzed and compared with results obtained from numerical simulations with the aim to evaluate the effect on the load caring capability of the impacted specimen.
Journal of environmental chemical engineering, Apr 1, 2023
Due to their unique combination of properties, Super Duplex Stainless Steels (SDSSs) are material... more Due to their unique combination of properties, Super Duplex Stainless Steels (SDSSs) are materials of choice in many industries. Their applications and markets are growing continuously, and without any doubt, there is a great potential for further volume increase. In recent years, intensive research has been performed on lean SDSSs improving mechanical properties exploiting the lack of nickel to generate metastable γ-austenite, resulting in transformation-induced plasticity (TRIP) effect. In the present work, a commercial F55-UNS S32760 SDSS have been studied coupling its microstructural features, especially secondary austenitic precipitates, and tensile properties, after different thermal treatments. First, the investigated specimens have been undergone to a thermal treatment solution, and then, to an annealing treatment with different holding times, in order to simulate the common hot-forming industrial practice. The results of microstructural investigations and mechanical testing highlight the occurrence of TRIP processes. This feature has been related to the Magee effect, concerning the secondary austenitic precipitates nucleated via martensitic-shear transformation.
Journal of Sustainable Metallurgy
Ladle furnace slags are characterized by volumetric expansions associated with the transition of ... more Ladle furnace slags are characterized by volumetric expansions associated with the transition of dicalcium silicate (C2S) from β to γ phase, which generates fine dust during cooling, causing handling and storage issues that further reduce their recycling opportunities. The present work focuses on the effect of slag basicity on dusting and the role of sulfur on slag stability. Seven synthetic ladle slag precursors were made by mixing lime, magnesia, quartz and alumina in different proportions to match effective industrial compositions, increasing the binary basicity and keeping the ternary and quaternary indexes unchanged. Samples were heated to 1500 °C for 15 min and monitored during air cooling (< 5 °C/s) through thermocouples and camera to characterize the behavior, temperature, and time interval of dusting. The cooled samples were characterized chemically, mineralogically and morphologically. Starting from the chemistry of a self-stabilized slag, five additional slag precursor...
Steel Research International, Feb 1, 2022
Accepted Article This article is protected by copyright. All rights reserved The in-plant recycli... more Accepted Article This article is protected by copyright. All rights reserved The in-plant recycling routes of several side streams produced in Electric Arc Furnace (EAF) steelmaking remain under-explored. Briquetting is an attractive technique to enable recycling of inplant side streams. Briquettes introduced into EAF must possess certain mechanical and chemical properties. However, no standard is available to determine the suitability of briquettes used in the EAF process. In this work, eight side streams were characterized, and used to produce seven different briquettes to be used in EAF. Side streams were obtained from three different EAF steel plants as well as two other industrial sites. Briquettes tested consisted of four self-reducing briquettes and three slag-forming briquettes produced using different recipes. The briquettes were subjected to several mechanical and thermal tests which reflect their intended use in EAF. The mechanical tests included compression and drop tests, and the thermal tests included optical dilatometry, TGA-DTG-MS, and full-scale briquette reduction tests. Moreover, melting trials were performed to assess the melting behavior of selected briquettes and their interaction with slag. Suitability of briquettes characteristics were assessed based on values from literature and against reference ferroalloys and lime stones used in one of the steel plants. Two briquettes were deemed suitable for EAF use, while three briquettes were deemed unsuitable, and two briquettes were considered of limited use.
ISIJ International
The Fines2EAF project aims to increase the value of Electric Arc Furnace steelmaking residues by ... more The Fines2EAF project aims to increase the value of Electric Arc Furnace steelmaking residues by their internal recycling and reuse in form of cement-free briquettes. The project sustainability for a profitable fines' recirculation pass through the conservation of steel and slag quality in terms of chemistry, physics and eco friendliness. To do this, industrial trials have been conducted by the charging of self-reducing and slag-former briquettes made by primary and secondary fines materials. Several slag samples supplied from three different European EAF steel shops have been analysed. The specimens have been characterized by XRF, XRD and SEM to thoroughly define their crystallography, morphology and microstructure. The comparison with the corresponding reference samples (i.e., slag produced without the fines recirculation) also allowed to highlight the differences present. Leaching tests have been conducted on reference and briquette-added slag according to EN 12457-4 standard to assess the compliant with the local environmental regulation. The obtained results highlighted that the slag obtained using cement-free briquettes made by steelmaking fines exhibits crystallographic and morphological properties very similar to the reference samples, with limited differences attributed to slag and scrap feedstock intrinsic heterogeneity. No relevant increase in the leachate concentration could be detected when compared to reference samples and the influence of raw-material fines recirculation into the EAF could be considered at worst negligible, if not positive for some elements like Ba (− 22.86%), V (− 13.19%) and W (− 14.83%). Considering all the analyses performed, no adverse effect on slag quality could be detected.
9th European Stainless Steel Conference - Science & Market & 5th European Duplex Stainless Steel Conference & Exhibition, 2017
Journal of the Brazilian Society of Mechanical Sciences and Engineering
This article comprehensively reviews the mechanical properties and tribo-metallurgical behavior o... more This article comprehensively reviews the mechanical properties and tribo-metallurgical behavior of 17-4 precipitation hardening stainless steel (17-4PH SS) during and after cold plastic deformation. Referring to the scientific literature, stainless steels are one of the few types of ferrous alloys which could be appropriately set up through cold working processes in the forms of sheets or other shapes. Likewise, some other metal alloys such as mild low-carbon-based steels, copper and its alloys, aluminum alloys, and some others are the few types of metal alloys which have this capability. On the other hand, in engineering applications, there are several types of mechanical failures, which must be taken into account to investigate the mechanical behavior and tribo-metallurgical properties of any targeted materials. For example, corrosion resistance, wear resistance, and fatigue failure are investigated according to the microstructural studies, comprising of the grain size, grain boun...
ISIJ international, 2022
The Fines2EAF project aims to increase the value of Electric Arc Furnace steelmaking residues by ... more The Fines2EAF project aims to increase the value of Electric Arc Furnace steelmaking residues by their internal recycling and reuse in form of cement-free briquettes. The project sustainability for a profitable fines’ recirculation pass through the conservation of steel and slag quality in terms of chemistry, physics and eco friendliness. To do this, industrial trials have been conducted by the charging of self-reducing and slag-former briquettes made by primary and secondary fines materials. Several slag samples supplied from three different European EAF steel shops have been analysed. The specimens have been characterized by XRF, XRD and SEM to thoroughly define their crystallography, morphology and microstructure. The comparison with the corresponding reference samples (i.e., slag produced without the fines recirculation) also
allowed to highlight the differences present. Leaching tests have been conducted on reference and briquette-added slag according to EN 12457-4 standard to assess the compliant with the local environmental
regulation. The obtained results highlighted that the slag obtained using cement-free briquettes made by steelmaking fines exhibits crystallographic and morphological properties very similar to the reference
samples, with limited differences attributed to slag and scrap feedstock intrinsic heterogeneity. No relevant increase in the leachate concentration could be detected when compared to reference samples and
the influence of raw-material fines recirculation into the EAF could be considered at worst negligible, if not positive for some elements like Ba ( − 22.86%), V ( − 13.19%) and W ( − 14.83%). Considering all the analyses performed, no adverse effect on slag quality could be detected.
Oggigiorno le scorie da forno elettrico ad arco sono considerate molto piu di una semplice altern... more Oggigiorno le scorie da forno elettrico ad arco sono considerate molto piu di una semplice alternativa ai materiali lapidei naturali. Le scorie d'acciaieria sono potenzialmente impiegabili in una molteplicita di applicazioni: per il riempimento di cave esauste, per la costruzione di strade e per la produzione di calcestruzzo, grazie alle loro proprieta fisiche equivalenti o talvolta superiori ai tradizionali materiali lapidei naturali, quali, ad esempio, la ghiaia. Purtroppo il loro impiego e limitato dalla presenza di elementi inquinanti, tra cui Cr, Ba, V e Mo, potenzialmente pericolosi per l'uomo e per l'ambiente. Pertanto, stabilita chimica e strutturale sono due requisiti fondamentali che le scorie devono soddisfare, specialmente per applicazioni in cui possono entrare in contatto con l'acqua. Infatti, la presenza di fasi con proprieta idrauliche quali larnite (2CaO.SiO2) o brownmillerite (4CaO.Al2O3.Fe2O3) puo implicare il rilascio dei metalli inquinanti nell&#...
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Papers by Davide Mombelli
allowed to highlight the differences present. Leaching tests have been conducted on reference and briquette-added slag according to EN 12457-4 standard to assess the compliant with the local environmental
regulation. The obtained results highlighted that the slag obtained using cement-free briquettes made by steelmaking fines exhibits crystallographic and morphological properties very similar to the reference
samples, with limited differences attributed to slag and scrap feedstock intrinsic heterogeneity. No relevant increase in the leachate concentration could be detected when compared to reference samples and
the influence of raw-material fines recirculation into the EAF could be considered at worst negligible, if not positive for some elements like Ba ( − 22.86%), V ( − 13.19%) and W ( − 14.83%). Considering all the analyses performed, no adverse effect on slag quality could be detected.
allowed to highlight the differences present. Leaching tests have been conducted on reference and briquette-added slag according to EN 12457-4 standard to assess the compliant with the local environmental
regulation. The obtained results highlighted that the slag obtained using cement-free briquettes made by steelmaking fines exhibits crystallographic and morphological properties very similar to the reference
samples, with limited differences attributed to slag and scrap feedstock intrinsic heterogeneity. No relevant increase in the leachate concentration could be detected when compared to reference samples and
the influence of raw-material fines recirculation into the EAF could be considered at worst negligible, if not positive for some elements like Ba ( − 22.86%), V ( − 13.19%) and W ( − 14.83%). Considering all the analyses performed, no adverse effect on slag quality could be detected.
Dr. Davide Mombelli
Prof. Carlo Mapelli
Guest Editors
Manuscript Submission Information
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.
The metallurgical industry is one of the most impacting human activities in terms of solid, liquid, and gaseous emissions. Metals production involves the extraction of metals ores processed by hydro-, pyro-, or hybrid-metallurgical processes, and it is always associated with the generation of an important amount of wastes. Unfortunately, for certain metals, i.e., rare earths, and noble metals, a shortage of raw materials that began a few decades ago due to an increase in their utilization for specific applications (solar panels, microelectronics, etc.). Generally, the solid and liquid residues from a specific metallurgy contain significant fractions of valuable elements suitable as raw materials for other metallurgies, like EAF dusts for Zn production. Thus, this Special Issue of Applied Sciences focuses on the possibility to extract (or recover) metals, oxides, or other compounds from metallurgical wastes (slag, dusts, sludges, skims, and dross) produced by the most widespread metallurgies (like iron-making, aluminum, copper, zinc, lead), noble metals (gold, silver, platinum, etc.), refractory metals (tungsten, molybdenum, cobalt, etc.), and rare earths. The purpose of this Issue is to collect novel and promising processes to recover valuable elements and compound from waste products. Pyro-, hydro-, or hybrid- metallurgical processes will be well accepted. Preferable papers will be those explaining a feasible process, at laboratory scale; a pilot plant; or an existing process, with special regard to the economic aspects of compound extractions and the environmental impact of process residues.
Dr. Davide Mombelli
Prof. Carlo Mapelli
Guest Editors
Manuscript Submission Information
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.
Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.