Miguel A. Monge

• University Carlos III de Madrid

The development of dispersion of nanoparticles in the W-1%Y$_2$O$_3$ and W-1%La$_2$O$_3$ (wt%) alloys processed by hot isostatic pressing has been investigated using small angle neutron scattering. The mode values of these centers are found at 10 and 40 nm in W-1%Y$_2$O$_3$, and 15 and 80 nm in W-1%La$_2$O$_3$. The scanning electron microscopy anal...

With the objective of contributing to the European development of materials, technologies and facilities for the demonstration of the thermonuclear fusion, the construction of the unique TechnoFusión facility was planned in 2009. The TechnoFusión consortium, formed by selected Spanish research groups and laboratories located in Madrid, has jointly...

Cu5Cr35Fe35V20-X5, with X = Ti, Ta or W, alloys were produced by arc melting to assess their feasibility to be used as structural materials and as interlayer in cooling systems. The microstructure and mechanical properties of the materials were analyzed in as-cast and aged states. In the as-cast state the structure of the three alloys is BCC, but f...

The oxidation behaviour of W-2Ti (wt.%) alloy has been evaluated in dry air at 600°C, 700 and 800°C for 100 h and the kinetics compared with those for pure tungsten. Titanium addition exerts a beneficial effect on the oxidation resistance of pure tungsten. The mass gain is almost five times smaller than in the case of commercial tungsten and three...

The microstructure, thermal stability, and mechanical properties of a novel Cr35Fe35V16.5Mo6Ti7.5 high-entropy alloy were studied. The mechanical properties were mapped by nanoindentation, and the results correlated with the microstructure and the Vickers microhardness measurements. The alloy was produced by arc melting in a low pressure He atmosph...

Cu5Cr35Fe35V20Ti5, Cu10Cr35Fe35V10Ti10, Cu15Cr35Fe35V5Ti10 and Cu20Cr30Fe30V10Ti10 were produced by low-pressure arc-melting to evaluate the feasibility of developing reduced activation high entropy alloys containing copper. The materials present a dendritic microstructure and some Cu and Ti segregation in the as-cast condition, being the Cu5Cr35Fe...

This work studies the thermal stability of the microstructure and the evolution of the defects of two high-heat flux Cu-0.8 wt%Y alloys fabricated following two alternative powder metallurgy routes. One batch was produced by direct hot isostatic pressing (HIP) consolidation of Cu-0.8 wt%Y pre-alloyed atomized powders while an additional ball millin...

A new oxide dispersion strengthened Cu–0.7wt-%Cr–0.11wt-%Zr material was processed via mechanical alloying (MA) and hot isostatic pressing (HIP). A fine dispersion of yttria particles (Y2O3) was incorporated to the Cu matrix via the addition of yttrium (III) acetate tetrahydrate (C6H9O6Y·4H2O) powder (Y3ATH), which decomposed during thermomechanica...

Dispersion strengthened copper alloys have been produced following an innovative powder metallurgy route. Copper and yttrium acetate powders have been mechanically alloyed and posteriorly thermal treated at 923 K for 3 h and 15 h under a hydrogen atmosphere in order to transform the yttrium acetate into Y2O3. Subsequently, the powders were consolid...

A new improved oxide dispersion strengthened (ODS) Eurofer steel was produced by a novel two step mechanical alloying route. Starting from atomized Eurofer powder, two batches of fine and coarse particles with average sizes of ∼60 μm and ∼120 μm were milled separately after the addition of Ti and nanosized Y2O3. The final blend of the two powder ba...

The influence of 1 and 5 wt. % of TiC nanoparticles on the oxidation behaviour of reinforced tungsten has been evaluated up to 700 °C in dry air. Isothermal thermogravimetric tests prove that the addition of 5 wt. % of TiC particles is detrimental, increasing the mass gain of pure tungsten by a factor of ten. TiC particles act as stress concentrato...

Two batches of dispersion strengthened copper alloys with a nominal composition Cu-0.8 wt%Y have been obtained following different powder metallurgy routes that include sintering by hot isostatic pressing and subsequent thermomechanical treatments. One batch, named Cu-0.8Y, was produced by sintering the raw prealloyed powder. To promote the formati...

Dispersion strengthened copper alloys have been produced by following a powder metallurgy route that have consisted of milling copper and yttrium acetate powders in a planetary ball milling and subsequently sintering by hot isostatic pressing (HIP). In order to increase the degree of densification of the materials, they were subjected to a thermal...

The effect of vanadium additions on the oxidation behaviour of tungsten has been evaluated at 600 °C in dry air. Mass gain in V-containing tungsten alloys is practically the same than that of pure tungsten processed by a conventional route. The advantage of vanadium alloying arises from the suppression of periodical microcracking described during t...

Fully dense W-15 wt%CuY and W-15 wt%CuCrZr composites have been produced by a powder metallurgy route and hot isostatic pressing. The consolidated materials show homogeneous distributions of pre-alloyed CuY and CuCrZr embedded in W phase. Y-enriched particles were found inside the CuY phase. Their mechanical behavior was studied under uniaxial comp...

Dispersion strengthened Cu-1%Y (wt%) has been produced by mechanical alloying and subsequent consolidation by hot isostatic pressing (HIP). Samples of this alloy have been submitted to an equal channel angular pressing (ECAP) process and the effects on the microstructure and mechanical properties analyzed. The characteristics of the microstructure,...

In this work the cytocompatibility of pure magnesium and Mg-xHAP composites (x = 5, 10 and 15 wt%) fabricated by powder metallurgy routes has been investigated. The materials were produced from raw HAP powders with particle mean sizes of 6 μm (S-xHAP) or 25 μm (L-xHAP). The biocompatibility study has been performed for MC3T3 cells (osteoblasts/oste...

Full density Cu-1%Y and Cu-0.8%Y alloys have been produced by different powder metallurgy routes and subsequent hot isostatic pressing. Some of the alloys have been subjected to equal channel angular pressing (ECAP) via BC route up to 8 passes. ECAP deformation homogenizes and refines the microstructure up to attaining a sub-micron grain structure....

AbstractOxide dispersion strengthened Fe14Cr and Fe14CrWTi alloys produced by mechanical alloying and hot isostatic pressing were subjected to isochronal annealing up to 1400 °C, and the evolution and thermal stability of the vacancy-type defects were investigated by positron annihilation spectroscopy (PAS). The results were compared to those from...

Magnesium/hydroxyapatite composites were produced by conventional extrusion and their mechanical behavior studied under uniaxial compression at room temperature. The results evidence the capability of the HA for strengthening the Mg material, lowering its microstructural anisotropy and inhibiting deformation twinning. They also reveal that the ECAP...

An oxide dispersion strengthened ODS ferritic steel has been produced by mechanical alloying of Fe–14Cr–2W–0.2Ti (wt.%) prealloyed powder with 0.55 (wt.%) Fe2Y intermetallic particles and consolidated by hot isostatic pressing. The microstructure after thermal treatments confirms the homogeneous precipitation of Y-Ti oxides with nanometric sizes. T...

SEM analyses of W-Ti and W-V alloys produced by a powder metallurgy route have revealed the presence of Ti or V pools with different sizes and shapes. The larger pools have sizes ranged between ~ 0.3 and several microns and are embedded between the matrix grains. The smaller Ti-rich (V-rich) particles, with sizes below ~ 0.3 μm, are spherical and t...

Commercially pure (CP) titanium has been subjected to hydrostatic extrusion at room temperature at true strains ranging from 0.70 to 3.24. Isochronal thermal treatments, from room temperature to 1200°C, have been performed and the thermal stability of the deformation-induced defects has been studied by positron annihilation spectroscopy (PAS). In n...

This study and a second part dedicated to the mechanical characterization provide a better knowledge of tungsten (W)-vanadium (V) alloys reinforced with yttrium oxide (Y2O3) particles, which have been scarcely investigated. Two W alloys (W-2 or 4 wt.% V-0.5 wt.% Y2O3) and a pure W material processed by powder metallurgy and consolidated by hot isos...

An ITER-grade Cu-Cr-Zr alloy was subjected to equal channel angular pressing (ECAP) at 400 degrees C via routes B-C and C, i.e. rotated 90 or 180 around the extrusion axis before subsequent passes. The microstructure of ECAP deformed samples showed shear bands confining small recrystallized grains of about similar to 0.2-1 mu m in size. The best me...

Composites consisting of tantalum fiber/powder dispersed in a nanostructured W matrix have been consolidated by spark and pulse plasma sintering as well as by hot isostatic pressing. The microstructural observations revealed that the tungsten–tantalum fiber composites consolidated by hot isostatic pressing and pulse plasma sintering presented a con...

W-2Ti and W-1TiC alloys were produced by mechanical alloying and consolidation by hot isostatic pressing. The composition and microstructural characteristics of these alloys were studied by X-ray diffraction, energy dispersion spectroscopy and scanning electron microscopy. The mechanical behavior of the consolidated alloys was characterized by micr...

Three copper base materials were fabricated following different routes: cast Cu-1 wt.%Y (C-Cu1Y) produced by vacuum induction melting, and Cu-1 wt.%Y (PM-Cu1Y) and Cu-1 wt.%Y2O3 (PM-Cu1Y2O3) both processed by a powder metallurgy route and sintering by hot isostatic pressing. PM-Cu1Y alloy was prepared by cryomilling and PM-Cu1Y2O3 by conventional m...

A nanograin sized model oxide dispersion strengthened (ODS) ferritic steel with nominal composition Fe-14Cr-0.3Y2O3 (wt-%) was produced by mechanical alloying and consolidated by hot isostatic pressing. The alloy was submitted to severe plastic deformation by equal channel angular pressing (ECAP). Microstructural and mechanical characterisation was...

This study evaluates the mechanical behaviour of an Y2O3-dispersed tungsten (W) alloy and compares it to a pure W reference material. Both materials were processed via mechanical alloying (MA) and subsequent hot isostatic pressing (HIP). We performed non-standard three-point bending (TPB) tests in both an oxidising atmosphere and vacuum across a te...

Electron back-scattered diffraction and positron annihilation lifetime measurements were performed on the ferritic–martensitic 9 %Cr Eurofer steel processed by equal channel angular pressing (ECAP) at 550 °C. The orientation imaging mapping images reveal ECAP-induced changes toward a more stable texture via rotation around 〈111〉 and 〈110〉 axes. The...

Mg and Mg-HAP composites containing 5, 10 and 15wt% of hydroxyapatite have been produced following a powder metallurgy route that consists of mixing raw powders and consolidation by extrusion. The microstructure, texture, mechanical behavior and resistance to corrosion under a PBS solution have been studied. Addition of HAP increases the microhardn...

Ordered B2-NiAl intermetallic compound powder was successfully synthesised by mechanical alloying after 20 h in an attritor mill, starting from elemental Ni and Al powders and without subsequent heat treatment. NiAl powder obtained was homogenous and had a nanocrystalline microstructure. It was consolidated by field assisted hot pressing (FAHP), in...

Coarse-grained commercially pure (CP) Titanium is subjected to hydrostatic extrusion resulting in formation of ultra-fine lamellar-type microstructure having very strong fibre texture. Uni-axial tensile tests of longitudinal and transverse specimens are carried out to study anisotropy of uni-axial deformation behaviour of hydrostatically extruded C...

The oxidation resistance in dry air of pure tungsten and tungsten reinforced with a dispersion of 0.6 wt.% Y2O3 nanoparticles has been evaluated between 873 and 1073 K, temperature range that divertor in fusion power plants should endure during long-term times in the case of loss of coolant accident and/or air ingress in the vessel. Both materials...

The mechanical behavior of three tungsten (W) alloys with vanadium (V) and lanthana (La2O3) additions (W-4%V, W-1%La2O3, W-4%V-1%La2O3) processed by hot isostatic pressing (HIP) have been compared with pure-W to analyze the influence of the dopants. Mechanical characterization was performed by three point bending (TPB) tests in an oxidizing air atm...

W-2V and ODSW-2V-0.5Y(2)O(3) alloys have been produced following a powder metallurgy route consisting of mechanical alloying and a subsequent high isostatic pressing HIP at 1573 K. The grain microstructure and microhardness recovery of the alloys have been studied in samples subjected to isothermal treatments in vacuum in temperature range 1073-197...

ODS and non-ODS alloys with target compositions: Fe-14Cr, Fe-14Cr-0.3Y 2 O 3 , Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 and Fe-14Cr-2W-0.3Ti-0.24Y (% wt) have been produced and characterized. The blends of elemental powders were mechanically alloyed in a planetary ball mill under an atmosphere of either helium or hydrogen. The milled powder was analyzed by scan...

The objective of the Project was the fabrication at laboratory scale of nano-grain sized model ODS ferritic steels with the composition Fe-14Cr-2W-0.3Ti-0.24Y (wt %). Two batches of samples with this nominal composition were produced by mechanical alloying of elemental powders and consolidated by hot isostatic pressing (HIP). One batch was submitte...

The capability of the colloidal method to produce yttria (Y 2 O 3) dispersed hydroxyapatite (HA) has been in-vestigated as an alternative method to the conventional method of mechanical mixing and sintering for de-veloping HA-based materials that could exhibit controllable and enhanced functional properties. A water based colloidal route to produce...

Microstructural characterization of stress states of alumina layers subjected to residual compressive stresses was performed by positron annihilation spectroscopy (PAS). Al2O3-t-ZrO2 three layered samples were appropriately designed and processed by sequential slip casting with symmetric structure. The zirconia contents inside the core layer were s...

The microstructure, texture and mechanical behavior of the powder metallurgy Al–5 wt.%Mg–1.2 wt.%Cr alloy subjected to equal channel angular pressing (ECAP) has been investigated. The material processed by ECAP, as well as in the homogenized condition, exhibited room temperature serrated flow (SF) up to fracture. The critical stress for the serrati...

The development of a dispersion of nanoparticles in the W–1%Y 2 O 3 and W–1%La 2 O 3 (wt%) alloys processed by hot isostatic pressing have been investigated using small-angle neutron scattering. The analyses of the scattering data using the Beaucage unified approach reveal the presence of a bi-modal distribution of spher-ical scattering centers wit...

The microstructure and the texture of extruded 6061 Al alloy processed by powder metallurgy (PM), using three different initial powder particle sizes, have been studied after torsion deformation at 300 °C at strain rate of 6 s−1. The initial extruded microstructure of the three alloys consisted of elongated grains confining substructure with a typi...

1. Production of Fe-14Cr-2W-0.3Ti-0.24Y alloy by MA+HIP 2. Microstructural characterization OM, SEM and TEM analysis 3. Mechanical characterization Vickers hardness Tensile tests

The oxidation behavior of International Thermonuclear Experimental Reactor (ITER)-reference tungsten grade has been evaluated in dry air in the temperature range 600–800 °C. At 600 °C, the scale remained protective while the integrity of W18O49 layer was kept. Rapid increase in mass gain resulted from massive cracking at local areas in the W18O49 l...

The objective of the Project was the fabrication at laboratory scale of nanograin sized model ODS ferritic steels with the composition Fe-14Cr-2W- 0.3Ti-0.3Y2O3 (wt %). Three batches of samples with this nominal composition have been produced by mechanical alloying of elemental powders, introducing the Y in the form of Y2O3, Fe5O12Y3 and pure Y. Mi...

The objective of the project has been the fabrication at laboratory scale of nano-grain sized model ODS ferritic steels. A variety of compositions has been obtained by mechanical alloying: ODS and non-ODS Fe-14Cr samples and ODS Fe-14Cr samples containing W and Ti. The Vickers hardness of the different powder samples in as-milled state has been mea...

Two ODS ferritic steels with nominal compositions (wt.%): Fe-14Cr-0.3Y2O3 and Fe-14Cr-2W-0.3Ti-0.3Y2O3 have been produced by mechanical alloying and consolidation by hot isostatic pressing. The microstructure and tensile properties of these materials after being forged and heat-treated at 1123 K have been investigated to clarify the interrelation b...

Probably the most important range of materials to consider for the blanket material in the tokamak design for fusion reactors such as ITER and DEMO is the high alloy Fe9Cr oxide dispersion strengthened (ODS) ferritic steels. These steels possess exceptional thermal conductivity and low thermal expansion while being strongly resistant to void swelli...

EUROFER’97 was processed by equal channel angular pressing (ECAP) at 823K for a total of 4 or 8 passes, using a die angle of 105°, and its microstructure and tensile behavior in temperature range 568–873K investigated. A single ECAP pass developed a deformation texture {110} 〈011〉 that was practically stable during subsequent ECAP passes. The mater...

Reduced activation ferritic Fe–14wt%Cr and Fe–14wt%Cr–0.3wt%Y2O3 alloys were produced by mechanical alloying and hot isostatic pressing followed by forging and heat treating. The alloy containing Y2O3 developed a submicron-grained structure with homogeneous dispersion of oxide nanoparticles that enhanced the tensile properties in comparison to the...

In this research the mechanical behaviour of pure tungsten (W) and its alloys (2wt.% Ti–0.47wt.% Y2O3 and 4wt.% Ti–0.5wt.% Y2O3) is compared. These tungsten alloys, have been obtained by powder metallurgy. The yield strength, fracture toughness and elastic modulus have been studied in the temperature interval of 25°C to 1000°C. The results have sho...

W and W–V alloys reinforced with La2O3 particles have been produced by MA and subsequent HIP at 1573K and 195MPa. The microstructure of the consolidated alloys has been characterized by scanning electron microscopy, energy dispersive spectroscopy analyses and X-ray diffraction. The mechanical properties were studied by nanoindentation measurements....

A powder metallurgy technique has been developed to produce oxide strengthened W–Ti and W–V alloys using elemental powders and nanosized powders of La2O3 or Y2O3 as starting materials. The alloys consolidated by hot isostatic pressing resulted in high-density materials having an ultrafine-grained structure and microhardness values in the range 7–13...

In response to the urgent request from the EU Fusion Program, a new facility (TechnoFusión) for research and development of fusion materials has been planned with support from the Regional Government of Madrid and the Ministry of Science and Innovation of Spain. TechnoFusión, the National Centre for Fusion Technologies, aims screening different tec...

The EUROFER 97 steel was processed by equal channel angular pressing (ECAP) at 550°C for four passes via route C. The starting material consisted of ferrite–martensite dual phase composed by small subgrains of about 0.5μm and low angle boundaries less than 5°. The volume fraction of second phase particles was around 10vol.%, besides a texture forme...

The objective of the Project was the fabrication at laboratory scale of a nano-grain sized model ODS ferritic steel with the composition Fe-14Cr-0.3Y2O3 (wt %). The alloy has been produced by mechanical alloying and consolidated by hot isostatic pressing (HIP). Different thermomechanical treatments have been used to produce a nano-grained steel. Th...

Reduced activation ferritic Fe–14 wt%Cr and Fe–14 wt%Cr–0.3 wt%Y 2 O 3 alloys were produced by mechanical alloying and hot isostatic pressing followed by forging and heat treating. The alloy containing Y 2 O 3 developed a submicron-grained structure with homogeneous dispersion of oxide nanoparticles that enhanced the tensile properties in compariso...

Fusion Engineering and Design j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / f u s e n g d e s a b s t r a c t In response to the urgent request from the EU Fusion Program, a new facility (TechnoFusión) for research and development of fusion materials has been planned with support from the Regional Government of Mad...

a b s t r a c t In this research the mechanical behaviour of pure tungsten (W) and its alloys (2 wt.% Ti–0.47 wt.% Y 2 O 3 and 4 wt.% Ti–0.5 wt.% Y 2 O 3) is compared. These tungsten alloys, have been obtained by powder metal-lurgy. The yield strength, fracture toughness and elastic modulus have been studied in the temperature interval of 25 °C to...

W and W alloys are currently considered promising candidates for plasma facing components in future fusion reactors but most of the information on their mechanical properties at elevated temperature was obtained in the 1960s and 1970s. In this investigation, the strength and toughness of novel Y2O3-doped W–Ti alloys manufactured by powder metallurg...

Positron annihilation spectroscopy (PAS), indentation, nanoindentation experiments and scanning electron microscopy (SEM) observations were performed on Al2O3–ZrO2 laminates samples to assess the effect of residual stresses on their mechanical and microstructural properties. Layered samples were implemented by slip-casting, constituted by two thin...

This report concerns the activities realized for EFDA by the ESTRUMAT-CM group at the University Carlos III of Madrid to fulfil the subtask EFDA WP08-09-MAT-ODSFS. This subtask is part of the activity 3: Developing the optimised generation of ODS nano-structured and nano-grained ferritic steels.

1. Fe‐14Cr, Fe‐14Cr‐0.3Y2O3 model alloys produced by MA+HIP+TMT 2. Fe‐14Cr, Fe‐14Cr‐0.3Y2O3 model alloys produced by MA+Spark Plasma Sintering 3. Grain refinement through Equal Channel Angular Pressing: effects in EUROFER and ODS‐EUROFER.

The mechanical behavior of pure W, W-0.5wtpct Y2O3, and W-4wtpct Ti manufactured by powder metallurgy was studied from ambient temperature to 1000°C. Y2O3 nanoparticles were added to inhibit grain growth and improve oxidation resistance, while Ti is a sintering activator. Strength and toughness were measured from the three-point bend tests in smoot...

The development of nuclear fusion is rapidly becoming a vital necessity in view of the continuing rise of the world’s energy demand. Nuclear fusion offers a virtually endless source of energy that is both environmentally friendly and capable of meeting any foreseeable energy demand. The progress of fusion constitutes one of the greatest technologic...

Porous hydroxyapatite and hydroxyapatite/oxide composites, with 10 wt% addition of Y2O3, ZrO2 or TiO2 have been prepared by hot isostatic pressing after pressureless sintering, and their phase composition, mechanical properties and microstructure investigated. The quantitative X-ray diffraction analyses reveal that the addition of Y2O3 inhibits the...

The yttria dispersion effect on the oxidation resistance of titanium prepared by powder metallurgy has been evaluated between 700 and 900 °C. Yttria additions slightly increase the oxidation rate up to 800 °C and decrease it considerably at 900 °C. The multilayered rutile scale formed on pure titanium prepared by conventional techniques is replaced...

Positron annihilation experiments were performed on oxide dispersion strengthened (ODS) and non-ODS EUROFER prepared by mechanical alloying and hot isostatic pressing. The results revealed the presence of small voids in these materials in the as-HIPed conditions. Their evolution under isochronal annealing experiments was investigated. The coinciden...

W and W alloys containing 0.5wt% Y2O3, xwt% Ti and (xwt% Ti+0.5wt% Y2O3) have been prepared, x=2 or 4. Elemental powders were blended or ball milled, canned, degassed and finally consolidated by a two-stage HIP process under a pressure of 195MPa. It is found that Ti addition favours the densification attaining a fully dense material. XRD, SEM and E...

Two Fe-12 wt% Cr alloys, one containing 0.4 wt% Y2O3 and the other Y2O3-free, have been produced by mechanical alloying followed by hot isostatic pressing. These oxide dispersion strengthened and reference alloys were characterized both in the as-HIPed state and after tempering by transmission electron microscopy and atom-probe tomography. The as-H...

Equal channel angular extrusion (ECAE) was performed in a conventionally extruded Mg–Ni–Y–RE material to develop fine-grained microstructures. The microstructure of the extruded alloy consisted of agglomerated phase particles zones (APZs) aligned along the extrusion direction and phase particles free zones (PFZs) containing recrystallized magnesium...

Coincidence doppler broadening (CDB) spectroscopy has been applied to study the precipitation process induced by aging in Mg–1.0wt.% Ca and Mg–1.0wt.% Ca–1.0wt.% Zn alloys. In addition positron lifetime experiments and microhardness measurements have been performed. A peak centered at ∼11.5×10−3m0c is found in the CDB ratio spectra of the alloys ag...

Yttrium oxide dispersion strengthened (ODS) and non-ODS EUROFER produced by mechanical alloying and hot isostatic pressing have been subjected to isochronal annealing up to 1523K, and the evolution of the open-volume defects and their thermal stability have been investigated using positron lifetime and coincidence Doppler broadening (CDB) technique...

Positron lifetime and wide-angle X-ray scattering measurements have been performed on ultra high molecular weight polyethylene deformed in uniaxial compression. No changes in the fraction of positronium states have been detected, suggesting that the fraction of free volume remains constant during deformation under the present conditions. The PALS r...

Two small ingots of the steel EUROFER 97, one containing 0.25wt% Y2O3 and the other Y2O3 free, have been produced by consolidating mechanically milled powder by hot isostatic pressing at 1373K for 2h under 200MPa. For comparison, a third ingot was consolidated under identical conditions but using un-milled EUROFER powder. Microhardness, tensile and...

Oxide dispersion strengthened steels based on the ferritic/martensitic steel EUROFER97 are promising candidates for a fusion reactor because of their improved high temperature mechanical properties and their potential higher radiation resistance relative to the base material. Several EUROFER97 based ODS F/M steels are investigated in this study. Th...

Y2O3-dispersed titanium with Y2O3 content ranging between 0.3 and 0.7 wt% was produced by an arc-melting technique starting from Ti and Y2O3. Compositional and microstructural characterization was performed by XRD, SEM and TEM for as-cast, forged and recrystallized samples. A uniform nanodispersion of Y2O3 particles with sizes <100 nm was found for...

In situ Ti/Y2O3 nanocomposites have been developed and characterized, and the strengthening effects of the fine Y2O3 dispersion investigated. Samples, containing 0.3–0.7 wt.% of Y2O3 were prepared by arc melting technique. TEM analyses performed on as-cast and recrystallization annealed samples reveal the presence of a homogeneous dispersion of Y2O...

Sintering of ball-milled and un-milled Fe powders has been investigated using dilatometry, X-ray, density, and positron annihilation techniques. A considerable sintering enhancement is found in milled powders showing apparent activation energies that range between 0.44 and 0.80eV/at. The positron annihilation results, combined with the evolution of...

Positron lifetime spectroscopy and wide-angle X-ray scattering have been applied to investigate the structural changes induced by tensile deformation in ultrahigh molecular weight linear polyethylene. The results reveal a correlation between the crystallinity, the positron annihilation characteristics, and the strain of the polymer. The probability...