Maria Richetta

Maria Richetta
University of Rome Tor Vergata | UNIROMA2 · Department of Industrial Engineering

Master of Research

About

225
Publications
24,682
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1,959
Citations
Introduction
• Materials of interest for fusion reactors (tungsten, ferritic steels) • Mechanical spectroscopy analysis of materials stability. Characterization by means of strummed nano-indentation. • Study of oxidative treatments on TiH2 powders, and analysis of their diffusion. • Nanomaterials synthesis, analysis and characterization. • LDH (Layered Double Hydroxides) characterization, morphological analysis, investigation of the growth mechanism. Study of the anticorrosive properties of ZnAl-LDH layers,

Publications

Publications (225)
Article
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Austenitic stainless steels produced by laser powder bed fusion (L-PBF) are quite interesting materials owing to their specific microstructure consisting of dendrite walls built of dislocations pinned by many nano-oxides that involves significant strengthening without loss of ductility. In this work, different plasma treatments were performed to ha...
Article
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In this work a W coating was deposited through PS in Ar-H2 atmosphere on a substrate of CuCrZr with an interlayer consisting of gradually changing fractions of Cu and W. The W coating and the interlayer showed good adhesion and no cracks were observed. The hardness of W and Cu along the interlayer was determined by nano-indentation tests and the re...
Article
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One of the big challenges for realizing future nuclear fusion reactors is the development of materials able to withstand the high thermal loads and particle fluxes typical of these reactors. This work investigated the residual stresses in a W coating deposited through plasma spraying on a substrate of CuCrZr alloy used in the active cooling system...
Chapter
Titanium alloys (e.g., Ti6Al4V) have been widely considered for the design of biomedical implants. To avoid stress shielding effects, bone atrophy and implant loosening bone, 3D porous devices with controlled geometry and architecture should represent a promising solution. Several cellular structures were already investigated to obtain a wide range...
Article
The work investigates refractory metals (bulk W, W produced via plasma spraying, W-1% La 2 O 3 and Mo) of interest as plasma facing materials in future nuclear fusion reactors. They have been irradiated by a single Nd:YAG laser pulse to simulate the effects of transient thermal loads of high energy occurring in a tokamak under operative conditions...
Article
The problems for fixing rib fractures are usually challenged with different rib fixators whose design strongly depends of the material selected for construction. Main issues refer to rib surgery implantation and tissue acceptance for a duration longer than the osteosynthesis. In this paper we discuss how a material selection can strongly suggest di...
Article
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The present work examines the effects of external and internal morphological features on the dynamic elastic modulus and its measure. It consists of two parts. The first part considers the effect of geometrical features of probes and shows the key role of roughness as source of a systematic error leading to the underestimation of the Young’s modulu...
Conference Paper
We investigated the adsorption of heavy metal ions on a nanostructured coating of zinc‐aluminum layered double hydroxides (Zn‐Al LDHs) grown on aluminum foam by one‐step hydrothermal process. This approach aimed to increase the interactive surface and provide a more practical medium for removal of toxic heavy metals from aqueous media. The foam coa...
Article
The W‐1%La2O3 alloy has been irradiated by a single laser pulse (λ = 1064 nm) to simulate transient thermal loads of high energy occurring in a tokamak under operative conditions. A zone with a diameter of ~2 mm, namely, much larger than the focal spot, results to be affected by the pulse, and a crater of about 300 μm is observed in its center. La2...
Article
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Molybdenum (Mo) is considered a plasma facing material alternative to tungsten (W) for manufacturing the divertor armours of International Thermonuclear Experimental Reactor (ITER). Transient thermal loads of high energy occurring in a tokamak during the service life have been simulated through a single laser pulse delivered by a Nd:YAG/Glass laser...
Article
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This contribution to ECPD2019 is dedicated to the memory of Anatoly Faenov. During a period of approximately thirteen years 1994–2006, Anatoly and his wife Tatiana Pikuz (simply “Tania” for friends), accepting the frequent invitations of the National Institute for Nuclear Physics (INFN) and of the Italian National Agency for New Technologies, Energ...
Article
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Layered double hydroxides (LDHs) are 2D ionic lamellar nanomaterials, which attract increasing interest for applications in different fields. This paper shows that their morphology is strongly affected by the microstructure of the substrate on which they grow. Zn–Al LDHs were grown in the same conditions on Al substrates with different microstructu...
Article
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Mechanical and architectural features play an important role in designing biomedical devices. The use of materials (i.e., Ti6Al4V) with Young’s modulus higher than those of natural tissues generally cause stress shielding effects, bone atrophy, and implant loosening. However, porous devices may be designed to reduce the implant stiffness and, conse...
Article
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In recent years, a great effort has been devoted to developing a new generation of materials for aeronautic applications. The driving force behind this effort is the reduction of costs, by extending the service life of aircraft parts (structural and engine components) and increasing fuel efficiency, load capacity and flight range. The present paper...
Article
Plasma enhancement gases (PEGs) (such as: N 2 , Ne, Ar and other inert gases) are injected into the plasma of several tokamaks in order to reduce the power load over the plasma facing components. The exhaust gas in the tokamak demonstration reactor (DEMO) consists of more than 90% of unburned fuel gas (D and T) and the remaining part will be He, PE...
Article
Full-text available
The control of the process–structure–property relationship of a material plays an important role in the design of biomedical metal devices featuring desired properties. In the field of endodontics, several post-core systems have been considered, which include a wide range of industrially developed posts. Endodontists generally use posts characteriz...
Article
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The conventional heat-treatment standard for the industrial post hot-forging cycle of AA7050 is regulated by the AMS4333 and AMS2770N standards. An innovative method that aimed to improve toughness behavior in Al alloys has been developed and reported. The unconventional method introduces an intermediate warm working step between the solution treat...
Article
Layered Double Hydroxides (LDHs) are 2D ionic lamellar nano-materials belonging to the group of anionic clays. Their structure consists of positively charged brucite-like layers and intercalated anions. The layered structure, together with the flexibility to intercept different anionic species (both inorganic and organic) in variable compositions h...
Article
An oxide dispersion strengthened (ODS) ferritic steel with nanometric grain size has been produced by means of low-energy mechanical alloying (LEMA) of steel powder (Fe-14Cr-1W-0.4Ti) mixed with Y 2 O 3 particles (0.3 wt%) and successive hot extrusion (HE). The material has equiaxed grains (mean size of 400 nm) and dislocation density of 4 x 10 ¹²...
Article
Layered double hydroxides (LDHs) are anionic clays composed by host layers of positively charged metal hydroxide, in which anions are intercalated to neutralize the charge of the positive layers. Because of the positive charge of the structure and because of their properties of anion exchanges, different anions can be intercalated into the structure...
Article
Modern cell culture as well as sophisticated bio-applications involve complex biochemical processes, which are required to induce growth, product development or material degradation. Tracking the reaction processes inside the application presents a major challenge due to its complexity. The development of new analysis and tracking mechanisms for su...
Article
Smartphones are developing into all-purposes devices. In the present work, the employment/application of smartphones as medical devices in home care and point-of-care (POC) diagnostics are investigated in the analysis of Lateral Flow Assays (LFA). A smartphone-based LFA reader was developed for the quantitative analysis of D-Dimer – a biomarker ind...
Article
The effect of an unconventional thermal treatment method aimed to improve toughness behavior in Al alloys is reported. The method involves solution heat treating and an intermediate warm working step, before final ageing thermal treatment on a AA7050 high resistance aluminum alloy. Results show the possibility to increase fracture toughness behavio...
Article
Modern medical science delivers through innovative chemical or mechanical/physical means new strategies to treat patients mildly and fight diseases accurately. In line with this development a screening procedure for tissue samples under usage of the electronic speckle pattern interferometry is developed at the University of Applied Science Wildau....
Article
The main purpose of the investigation is to develop reliable methods to repair IN 792 superalloy components by Laser Beam Welding (LBW). The jet engine structural components made of nickel-base superalloys are subjected to high stresses and severe environmental, therefore crack may occurs during in-service life. Considering the high cost of this co...
Article
A novel methodology based on electrochemical hydrogen permeation tests is proposed to study the efficiency of commercial inhibitors for industrial acid pickling of iron and mild steels. Weight loss measurements and hydrogen permeation tests have been carried out in order to compare the sensitivity of different techniques to variations of low inhibi...
Article
In recent years, the monitoring of the energy consumption in the industrial processes shows a growing interest due to its strong fallout on environmental pollution and environmental sustainability. On this purpose, this paper deals with the design of a portable Digital Acquisition system (DAQ) tailored for monitoring the energy consumption in diffe...
Article
Hydrogen storage is one of the most important industrial applications of titanium hydride (TiH 2 ). A critical issue is the hydrogen release rate that strongly depends on the surface structure of TiH 2 particles. This work reports the results of an experimental campaign carried out on TiH 2 powders submitted to heat treatments in air at different t...
Article
Low and medium Z impurity seeding gases, or plasma enhancement gases (PEGs) will be injected into the plasma of a Tokamak to convert the plasma thermal energy to ultraviolet and soft X-ray radiation. Possible PEGs are nitrogen, neon, argon, xenon and other inert gases. for the exhaust processing system of the demonstration fusion reactor (DEMO), th...
Article
Zinc‐aluminium layered double hydroxide (LDH) containing an ionic liquid, 1‐butyl‐3‐methylimidazolium hydrogen sulphate (BmimSO4), has been synthesized by the co‐precipitation method. This strategy enabled the intercalation of the ionic liquid (IL) into the interlamellar space of LDH with the aim of increasing the ionic conductivity and reducing it...
Article
The importance of inorganic membranes for gas separation and purification is analyzed. Although the cost of inorganic membranes is higher than that for polymeric membranes, they have higher permeance, selectivity and better resistance to higher pressure and temperature. The main materials used for porous inorganic membranes are alumina (Al2O3), sil...
Article
The term layered double hydroxides (LDHs) is used to define synthetic or natural lamellar hydroxides with 2 or more kinds of metallic cations in the main layers, and hydrated interlayer domains, containing anionic species. Layered double hydroxides, also known as hydrotalcite materials, have attracted considerable interest from both industry and ac...
Article
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W-1% La2O3 has been irradiated by a single laser pulse (λ = 1064 nm, pulse duration τ ≈ 15 ns, pulse energy Ep ≈ 4 J, spot size Φ = 200 μm, surface power density I = 8.5 × 1011 W·cm−2) to simulate the effects of transient thermal loads of high energy occurring in a tokamak under operative conditions. The samples have been then examined by scanning...
Article
The tool industry strongly demands more economical, high‐performance, healthy, and ecological Co‐free WC‐based composites. Nickel is considered the optimal substitute of Co in WC‐based cermets to attain nearly comparable, if not superior properties in terms of wear resistance and fracture toughness. The combination of WC‐Ni with spark plasma sinter...
Article
Titanium hydride (TiH2) is a brittle powder, which is highly reactive when exposed to heat or strong oxidizers. Namely due to its high reactivity, TiH2 powder is widely applied in pyrotechnics, initiator squibs, and igniters. All the industrial applications of TiH2 are based on its decomposition and consequent hydrogen release. The surface of TiH2...
Article
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The control of a microstructure, during and after hot forming, is crucial to tailor optimum mechanical properties for specific applications. Recrystallization is a key process which may contribute to a great extent to microstructure development. Dynamic recrystallization is becoming an attracting research area to investigate novel hot forming route...
Article
The study of laser compressed matter, both warm dense matter (WDM) and hot dense matter (HDM), is relevant to several research areas, including materials science, astrophysics, inertial confinement fusion. X-ray absorption radiography is a unique tool to diagnose compressed WDM and HDM. The application of radiography to shock-wave studies is presen...
Article
ZnAl Layered Double Hydroxide (LDH) films were grown on aluminum substrates with different anions by a one-step, hydrothermal process at 80 °C, in which the metal substrate acts as both reactant and support. Since the films are made of partially-oriented nanoplatelets with controllable size and density, this approach can be a promising strategy for...
Article
Oxide dispersion strengthened (ODS) steels are promising materials for high temperature applications, in particular in fission and fusion nuclear reactors. In comparison to common reduced activation ferritic/martensitic steels they exhibit better resistance to neutron irradiation and creep owing to an uniform dispersion of nano-oxides particles (~5...
Article
During the last years, various approaches on an individualized drug therapy for benign cells have been researched. However, due to the complex topic a universal approach has not been found up until this point. Commonly, the effect of cytotoxic drugs on benign cells is in most cases the same compared to regular cells while the actual effect on patie...
Article
Full-text available
Tungsten (W) is considered a promising plasma-facing material for protecting the divertor of the ITER (International Thermonuclear Experimental Reactor). The effects on W of transient thermal loads of high energy occurring in a tokamak under operative conditions have been simulated through a single laser pulse delivered by an Nd:YAG laser. Bulk and...
Article
Oxide dispersion strengthened steels are candidate materials for structural constituents in IV generation fission nuclear reactors and for fusion nuclear reactors. A reduced activation nano-oxide strengthened ferritic steel is produced by mechanical alloying with an average grain size of 400 nm. The steel is produced starting from nanometric powder...
Article
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The standard NACE MR0175 (ISO 15156) requires a maximum hardness value of 23 HRC for 13Cr-4Ni-(Mo) steel grade for sour service, requiring a double tempering heat treatment at temperature in the range 648–691°C for the first tempering and 593–621°C for the second tempering. Difficulties in limiting alloy hardness after the tempering of forged mecha...
Article
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Electron Beam (EB) welding has been used to realize seams on 2 mm-thick plates of directionally solidified (DS) IN792 superalloy. The first part of this work evidenced the importance of pre-heating the workpiece to avoid the formation of long cracks in the seam. The comparison of different pre-heating temperatures (PHT) and pass speeds (v) allowed...
Article
Full-text available
An oxide dispersion strengthened (ODS) ferritic steel with nanometric grain size has been produced by low-energy mechanical alloying (MA) of steel powder (Fe-14Cr-1W-0.4Ti) mixed with Y2O3 particles (0.3 wt %) and successive hot extrusion (HE). The material exhibits superior mechanical properties with respect to the unreinforced steel up to 400 _C,...
Article
Full-text available
Mechanical Spectroscopy (MS) tests have been performed on a high nitrogen (0.8 wt %) austenitic steel (HNS) with resonance frequencies in the range of kHz. Two sets of samples have been examined: the first set in an as-prepared condition, the second one submitted to a heat treatment of 2 h at 800 °C, which induces a discontinuous precipitation of C...
Article
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p>Even if relations predicting the mechanical properties on bars of austenitic stainless steels are already available, but no systematic works was carried out in order to predict mechanical properties in after cold rolling and annealing. The tensile properties of a large number of cold rolled and annealed AISI 304 stainless steel are here correlate...
Article
Multimegabar laser-driven shock waves are unique tools for studying matter under extreme conditions. Accurate characterization of shocked matter is for instance necessary for measurements of equation of state data or opacities. This paper reports experiments performed at the LULI facility on the diagnosis of shock waves, using x-ray-absorption radi...
Chapter
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The increasing level of air pollution in our cities due to emissions from fac-tories, vehicles and domestic heating, combined with the growing threat of terrorism, requires finding equipment and know-how that are useful for the detection and monitoring of hazardous substances and their dispersion into the atmosphere as quickly and far away as possi...
Article
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The duplex stainless steel 2205 was heat treated at 750◦C, 850◦C, and 900◦C for increasing durations of up to 10 h. The samples were investigated through light microscopy (LM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) to characterize the volume fraction and morphology of the precipitated secondary phases. The samples were...
Article
To fulfill the industrial demand of forged steels with high mechanical and microstructural requirements coupled with reduced cost, the possibility to decrease the content of Mo and other alloying elements has been evaluated. The effect of boron addition (up to 30 ppm) on the steel hardenability has been investigated on two steels with different che...
Article
The effect of two different cooling rates on the fatigue behaviour of a AA 2014 T6 alloy is reported in this paper. The study has been completed by a microstructural analysis carried out by means of scanning electron microscope, aimed to put in evidence the effect of microstructural evolution on the fatigue behaviour. A poor effect of the coooling...
Article
The peculiar properties of layered Double Hydroxides (LDH) have progressively drawn the attention of the scientific community. The main characteristic of LDH is the ability to capture anionic species (organic and inorganic) to build different composites. This is made possible by the sandwich structure of the LDH, similar to the brucite architecture...
Article
Microstructural stability is one of the utmost important requirements for metallic materialsin engineering applications, particularly at high temperatures. The paper shows how Mechanical Spectroscopy (MS) (i.e., damping and dynamic modulus measurements) permits the monitoring of the evolution of lattice defects, porosity, and cracks which strongly...
Article
Full-text available
In spite of the potentially harmful effects of vibrations on the human body, a new path was recently opened for the use of these mechanical means in the therapeutic field. The stimulation of proprioceptive and exteroceptive sensitivity is the main target in both peripheral (diabetes type 1 and type 2) and central (stroke, Parkinson's disease multip...
Article
The determination of mechanical properties can provide insight into complex biochemical processes such as the cell cycle and even the progression of diseases. However, this field of biomechanical research strongly depends on a high-resolution measurement technology and a gentle stimulation method in order to examine these mostly biological samples...
Article
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This work presents a photolithographic rapid prototyping process for producing thin films ("Rapid Phototyping"). This process allows a quick and cost-effective generation of scalable thermopile microstructures using commercial equipment and materials. Structural widths of 100x250μm can be produced reproducible in a lift-off process with an accuracy...
Article
Many pharmaceutical industries all around the world are facing the problem of dust mobilization during the productive process of medicines. This mobilization can be dangerous for the safety of the operators working in the factory and for the safety of the factory itself. It is therefore necessary to develop predictive models to simulate and forecas...
Article
An essential part of cell cultivation via cell culture technology is the determination and monitoring of culture parameters. Such parameters refer to the vitality or mutual mutations of the cell culture, while the actual number of living cells in each batch indicates the correct growth rate rather than stagnation or an overgrowth of the cell cultur...
Article
W is a plasma-facing material candidate for applications in future nuclear fusion reactors (NFR). In this work transient thermal loads of high energy have been simulated by interaction with a single laser pulse. The experiments have been carried out by using the Nd:Glass TVLPS laser working in first harmonic (wavelength λ = 1064 nm); the pulse para...
Article
Full-text available
Urban air pollution causes deleterious effects on human health and the environment. To meet stringent standards imposed by the European Commission, advanced measurement methods are required. Remote sensing techniques, such as light detection and ranging (LiDAR), can be a valuable option for evaluating particulate matter (PM), emitted by vehicles in...
Article
Full-text available
Two types of (Zn, Al) layered double hydroxide were prepared by a hydrothermal process at room temperature using Zn salt precursors on Al foils. The examined LDHs differ for the hosted anions in the interlamellar space, namely Cl- and NO3-. Scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy hav...