Cobalt free metallic binders for HVOF thermal sprayed wear resistant coatings

Thermal sprayed HVOF WC-based cermet coatings containing various metallic binders have been used in several different applications in industries that require abrasive sliding wear resistance, such as hydraulic pistons, shafts or bearings. The potential dangerousness and cost increase off cobalt-based metallic binders, underlining the challenge in reducing reliance on this metal as metallic binder in wear resistant coatings. The present work aims to study the feasibility of WC-NiMoCrFeCo, WC-CrC-Ni and WC-FeCrAl coatings, in contrast to conventional WCCoCr, by evaluating their microstructure, mechanical, tribological and corrosion resistance properties. Commercially feedstock powders were sprayed onto steel plates using a kerosene-fuelled HVOF WokaJet 400 gun. The WC-CoCr coating shows a slightly highest hardness than WC-NiMoCrFeCo and WC-FeCrAl coatings, showing a slight trend towards an increase in the wear rate as the coating hardness decreases. The WC-CrC-Ni coating is significantly the softest and least wear resistant coating, as a consequence of the presence of a high percentage of lower hardness CrC particles. Nevertheless, this coating shows similar corrosion resistance to of conventional WC-CoCr coating, while the WC-NiMoCrFeCo and WC-FeCrAl coatings show a slightly worse corrosion resistancPeer ReviewedPostprint (published version

Rheological Behavior of the A356 Alloy in the Semisolid State at Low Shear Rates

To control the semisolid processing of aluminum alloys produced by the additive manufacturing technique, an exhaustive knowledge of their rheological behavior is required. In the semisolid state, metallic materials can show rheological characteristics similar to those of polymers, so semisolid state shaping is one of the currently considered routes for additive manufacturing with metallic materials. In this work, an approximation of the rheological control of the A356 aluminum alloy for its subsequent 3D manufacturing was carried out at a very low shear rate. A continuous cooling rheometer was designed and used, evaluating the influence of different process parameters on the viscosity variation of the aluminum alloy in the semisolid state. The results show an anomalous flow variation, indicating dilatant, and not thixotropic behavior, for very low shear rates.Peer ReviewedPostprint (published version

Decorartive PVD coatings as an environmentally clean alternative to chrome plating

Peer ReviewedPostprint (published version

Effect of oxygen/fuel ratio on the in-flight particle parameters and properties of HVOF WC–CoCr coatings

High Velocity Oxy-Fuel (HVOF) spray techniques can produce high performance alloy and cermet coatings for applications that require wear resistant surfaces. In HVOF spraying heat is produced by burning mixtures of oxygen and fuel, mainly hydrogen, kerosene, propane, propylene, natural gas or acetylene. In these processes, the particle velocity and temperature determine the resultant coating properties and in many cases enables a better understanding of the process. The aim of this study is to investigate influences of different oxygen/fuel ratios on velocity and temperature of flying particles as well as properties of the HVOF thermal sprayed WC-CoCr coatings. In this work the feedstock powders were thermally sprayed by two different variants of the high velocity oxy-fuel process, in which the fuels were hydrogen and kerosene. Particle parameters were recorded just prior to impact on the substrate using in-flight particle diagnostic tool Accuraspray-g3®. Detailed correlation of particle parameters and the coating properties is evaluated in order to deduce particle parameter ranges providing coatings with optimum properties.Postprint (published version

Differential Effects of IGF-1R Small Molecule Tyrosine Kinase Inhibitors BMS-754807 and OSI-906 on Human Cancer Cell Lines

We have determined the effects of the IGF-1R tyrosine kinase inhibitors BMS-754807 (BMS) and OSI-906 (OSI) on cell proliferation and cell-cycle phase distribution in human colon, pancreatic carcinoma, and glioblastoma cell lines and primary cultures. IGF-1R signaling was blocked by BMS and OSI at equivalent doses, although both inhibitors exhibited differential antiproliferative effects. In all pancreatic carcinoma cell lines tested, BMS exerted a strong antiproliferative effect, whereas OSI had a minimal effect. Similar results were obtained on glioblastoma primary cultures, where HGUE-GB-15, -16 and -17 displayed resistance to OSI effects, whereas they were inhibited in their proliferation by BMS. Differential effects of BMS and OSI were also observed in colon carcinoma cell lines. Both inhibitors also showed different effects on cell cycle phase distribution, BMS induced G2/M arrest followed by cell death, while OSI induced G1 arrest with no cell death. Both inhibitors also showed different effects on other protein kinases activities. Taken together, our results are indicative that BMS mainly acts through off-target effects exerted on other protein kinases. Given that BMS exhibits a potent antiproliferative effect, we believe that this compound could be useful for the treatment of different types of tumors independently of their IGF-1R activation status.This research was funded by a Grant from Instituto de Salud Carlos III Grant PI012/02025 co-supported by FEDER funds and PRECIPITA crowdfunding platform from Fundación Española para la Ciencia y la Tecnología (Fecyt) to M. Saceda and AMACMED (Asociación de mujeres afectadas por cáncer de mama de Elche y Comarca) and Monica Moraleda donation to M. Saceda. The Spanish Ministry of Economy and Competitiveness (MINECO, Project RTI2018-096724-B-C21) and the Generalitat Valenciana (PROMETEO/2016/006) supported the work in the Encinar laboratory

Surface finish effect on the anodizing behaviour of Al-Si components obtained by sub-liquidus casting process.

The aim of this study was to investigate the hard decorative anodizing components of A357 aluminium alloy, obtained in semisolid state by Sub Liquidus Casting® process, to improve its tribological properties and corrosion resistance. Components were heat treated in order to modify the shape and distribution of the eutectic silicon phase. The influence of shot peening pre-treatment on anodizing process was evaluated. Surface modifications were investigated as they might have beneficial effects on the wear and corrosion behaviour. Furthermore, the influence of surface condition on the anodization colouring behaviour of aluminium was studied. The microstructure and the surface finish influence on the anodic oxide film growth were studied by optical and scanning electron microscopy. Experiments using a tribometer (ball on disc configuration) were performed in order to evaluate the tribological properties of the material. Salt spray corrosion tests were used to study the corrosion properties before and after the anodizing process.Peer ReviewedPostprint (published version

Radiotherapy resistance acquisition in Glioblastoma. Role of SOCS1 and SOCS3

Glioblastoma multiforme (GBM) is a poor prognosis type of tumour due to its resistance to chemo and radiotherapy. SOCS1 and SOCS3 have been associated with tumour progression and response to treatments in different kinds of cancers, including GBM. In this study, cell lines of IDH-wildtype GBM from primary cultures were obtained, and the role of SOCS1 and SOCS3 in the radiotherapy response was analysed. Fifty-two brain aspirates from GBM patients were processed, and six new cell lines of IDH-wildtype GBM were established. These new cell lines were characterized according to the WHO classification of CNS tumours. SOCS1 and SOCS3 expression levels were determined, at mRNA level by Q-PCR, at protein level by immunocytochemistry, and Western blot analysis. The results showed that SOCS1 and SOCS3 are overexpressed in GBM, as compared to a non-tumoral brain RNA pool. SOCS1 and SOCS3 expression were reduced by siRNA, and it was found that SOCS3 inhibition increases radioresistance in GBM cell lines, suggesting a key role of SOCS3 in radioresistant acquisition. In addition, radioresistant clonal populations obtained by selective pressure on these cell cultures also showed a significant decrease in SOCS3 expression, while SOCS1 remained unchanged. Furthermore, the induction of SOCS3 expression, under a heterologous promoter, in a radiotherapy resistant GBM cell line increased its radiosensitivity, supporting an important implication of SOCS3 in radiotherapy resistance acquisition. Finally, the treatment with TSA in the most radioresistant established cell line produced an increase in the effect of radiotherapy, that correlated with an increase in the expression of SOCS3. These effects of TSA disappeared if the increase in the expression of SOCS3 prevented with an siRNA against SOCS3. Thus, SOCS3 signal transduction pathway (JAK/STAT) could be useful to unmask new putative targets to improve radiotherapy response in GBM.This article has been funded by a grant from “Instituto de Salud Carlos III” (Grant PI012/02025), co-supported by FEDER funds, to M. Saceda; “Fundación ERESA” small project to M.Saceda, FISABIO grant (UGP-15-237) to V. M. Barberá, and a donation from AFECANCER to M.Saceda

CIÈNCIA DELS MATERIALS (Examen 2n quadrimestre)

Segon examen parcial i final del curs 2018-2019. Informacions a tenir en compte: "Los alumnos que hagan el examen final tienen que contestar las preguntas: 1 a 10 y de la 16 a la 19. Los alumnos que hagan el 2on parcial tienen que contestar las preguntas: 6 a 15 y de la 17 en adelante. Cada pregunta del test vale 0,3 puntos. Respuestas incorrectas restan 0,2. No se evaluará ningún examen que no contenga todos los datos identificativos del encabezamiento Si no se indican las unidades correctas en los diferentes apartados no se considerará la respuesta."Resolve

CIÈNCIA DELS MATERIALS (Examen 2n quadrimestre)

Examen de re-avaluació del curs 2018-2019. Informació a tenir en compte: "Cada pregunta del test vale 0,2 puntos. Respuestas incorrectas restan 0,1. No se evaluará ningún examen que no contenga todos los datos identificativos del encabezamiento. Si no se indican las unidades correctas en los diferentes apartados no se considerará la respuesta."Resolve

CIÈNCIA DELS MATERIALS (Examen 2n quadrimestre)

Segon examen parcial i final del curs 2018-2019. Informacions a tenir en compte: "Los alumnos que hagan el examen final tienen que contestar las preguntas: 1 a 10 y de la 16 a la 19. Los alumnos que hagan el 2on parcial tienen que contestar las preguntas: 6 a 15 y de la 17 en adelante. Cada pregunta del test vale 0,3 puntos. Respuestas incorrectas restan 0,2. No se evaluará ningún examen que no contenga todos los datos identificativos del encabezamiento Si no se indican las unidades correctas en los diferentes apartados no se considerará la respuesta."Resolve