Bulk TiCxN1-x-15%Co cermets obtained by direct spark plasma sintering of mechanochemical synthesized powders

TiCxN1-x-15 wt.%Co cermets were obtained by a mechanically induced self-sustaining reaction (MSR) and sintered by spark plasma sintering (SPS) technique at different temperatures (1200-1400 degrees C) for 1 min in vacuum under a uniaxial load of 80 MPa. The evolution of microstructure and mechanical properties was investigated. SPS allowed high densification with limited grain growth at a relatively low temperature. Material sintered at 1300 degrees C showed a good combination of mechanical properties with Vickers hardness of 17.1 +/- 0.5 GPa, fracture toughness of 5.51 +/- 0.29 MPa m(1/2) and bending strength of 904 +/- 12 MPa. Lower sintering temperature resulted in a decrease in bending strength due to poor cohesion between the ceramic and binder phases. An increase in sintering temperature would allow tailoring the cermet microstructure and, therefore, adjusting the Vickers hardness/fracture toughness relation. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.This work was supported by the Spanish Government under grant (MAT2011-22981), which is financed in part by the European Regional Development Fund of 2007-2013. A. Borrell acknowledges the Spanish Ministry of Science and Innovation for her "Juan de la Cierva" contract (JCI-2011-10498).Borrell Tomás, MA.; Salvador Moya, MD.; Rocha, VG.; Fernandez, A.; Angel Aviles, M.; Gotor, FJ. (2012). Bulk TiCxN1-x-15%Co cermets obtained by direct spark plasma sintering of mechanochemical synthesized powders. Materials Research Bulletin. 47(12):4487-4490. https://doi.org/10.1016/j.materresbull.2012.09.066S44874490471

Improvement of CNFs/SiC nanocomposites properties obtained from different routes and consolidated by pulsed electric-current pressure sintering

The influence of the preparation route and composition on carbon nanofibers-silicon carbide (CNFs/SiC) nanocomposites' properties was studied. Nanopowders were mixed by ultrasonic dispersion or high attrition milling and the consolidation was done by pulsed electric-current pressure sintering technique. The relative density and fracture strength of high-energy attrition milled CNFs/SiC nanocomposites gradually increased with the increase of sintering temperature, from 1400 to 1800 degrees C and holding time 1 to 30 min. A chemical surface coating of CNFs with alumina precursor is proposed as a very effective way for improving the interaction between CNFs and SiC. An increase of 54% in fracture strength was achieved on the nanocomposites when the surface coating was used. As a consequence of the stronger interaction between the components, which is achieved through the use of suitable processing route and sintering parameters, and the role of nano-alumina as sintering aid improved mechanical properties was achieved. (c) 2012 Elsevier B.V. All rights reserved.This work has been carried out with the financial support of the National Plan Projects nos. MAT2006-01783 and MAT2007-30989-E and the Regional Project no. FICYT PC07-021. A. Borrell, acknowledges the Spanish Ministry of Science and Innovation for her Juan de la Cierva contract (no. JCI-2011-10498).Rocha, VG.; Borrell Tomás, MA.; Torrecillas, R.; Fernandez, A. (2012). Improvement of CNFs/SiC nanocomposites properties obtained from different routes and consolidated by pulsed electric-current pressure sintering. Materials Science and Engineering: A. 556:414-419. https://doi.org/10.1016/j.msea.2012.07.006S41441955

ZrTiO4 materials obtained by Spark Plasma Reaction Sintering

Zirconium titanate (ZrTiO4), have many attractive properties such as high resistivity, high dielectric constant, high permittivity at microwave frequencies and excellent temperature stability for microwave properties. Zirconium titanate dense materials are proposed for many structural applications, but fully reacted and completely dense pieces are difficult to obtain by conventional routes. In this work, fully dense zirconium titanate materials ( 98%) were obtained at lower temperatures (1300 1400 C) and short processing time by non-conventional technique; spark plasma-reaction sintering (SPRS). Homogeneous and stable starting powders mixture with the adequate composition was prepared from the raw materials: m-ZrO2 ( 0.3 lm) and anatase-TiO2 ( 40 nm). Dense materials were mechanically and microstructural characterised. The fracture strength was measured by biaxial testing, giving values of about 200 MPa.This study has been supported by the Spanish Ministry of Science and Innovation MAT2009-14144-C03-02, MAT2012-38364-C03-02 and MAT2012-31090. A. Borrell, acknowledges the Spanish Ministry of Science and Innovation for her Juan de la Cierva contract (JCI-2011-10498) and the Generalitat Valenciana for the BEST/2012/302 grant and the financial support for ACOMP/2012/166.Borrell Tomás, MA.; Salvador Moya, MD.; García-Rocha, V.; Fernández, A.; Gómez, A.; López-López, E.; Moreno, R. (2014). ZrTiO4 materials obtained by Spark Plasma Reaction Sintering. Composites Part B: Engineering. 56:330-335. https://doi.org/10.1016/j.compositesb.2013.08.046S3303355

Enhanced properties of alumina-aluminium titanate composites obtained by spark plasma reaction-sintering of slip cast green bodies

Full dense alumina + 40 vol.% aluminium titanate composites were obtained by colloidal filtration and fast reaction-sintering of alumina/titania green bodies by spark plasma sintering at low temperatures (1250-1400 degrees C). The composites obtained had near-to-theoretical density (> 99%) with a bimodal grain size distribution. Phase development analysis demonstrated that aluminium titanate has already formed at 1300 degrees C. The mechanical properties such as Vickers hardness, flexural strength and fracture toughness of bulk composites are significantly higher than those reported elsewhere, e.g. the composite sintered at 1350 degrees C show values of about 24 GPa, 424 MPa and 5.4 MPa m(1/2), respectively. The improved mechanical properties of these composites are attributed to the enhanced densification and the finer and more uniform nanostructure achieved by non-conventional fast sintering of slip-cast dense green compacts. Crown Copyright (c) 2012 Published by Elsevier Ltd. All rights reserved.This study has been supported by the Spanish Ministry of Science and Innovation MAT2009-14369-C02-01 and MAT2009-14144-C03-02. A. Borrell, acknowledges the Spanish Ministry of Science and Innovation for her Juan de la Cierva contract (JCI-2011-10498) and the Generalitat Valenciana for the BEST/2012/302 grant and the financial support for ACOMP/2012/166.Borrell Tomás, MA.; Salvador Moya, MD.; Rocha, VG.; Fernandez, A.; Molina, T.; Moreno, R. (2013). Enhanced properties of alumina-aluminium titanate composites obtained by spark plasma reaction-sintering of slip cast green bodies. Composites Part B: Engineering. 47:255-259. https://doi.org/10.1016/j.compositesb.2012.11.010S2552594

Sydänpotilaan elämänlaatua lisää hyvä suun terveys : opetusanimaatio suun omahoidosta Kardiologian poliklinikan sairaanhoitajien ja potilaiden terveysvalmennukseen

Terve suu on osa ihmisen yleisterveyttä ja sen merkitys on tärkeä kokonaisvaltaisen hyvinvoinnin kannalta. Suun sairaudet voivat vaikuttaa haitallisesti yleisterveyteen, esimerkiksi sydänpotilaan hoidon ennusteeseen. Sydänpotilaiden suun sairauksia tulisi ennaltaehkäistä lisäämällä sairaanhoitajien ja sydänpotilaiden tietämystä suun terveydestä. Tämän opinnäytetyön tarkoitus oli vahvistaa Kardiologian poliklinikan sairaanhoitajien ja sydänpotilaiden tietämystä suun ja sydämen terveyden välisestä yhteydestä. Tavoitteena oli tuottaa suun terveydestä kertova animaatio sairaanhoitajille hyödynnettäväksi sydänpotilaiden hoidossa. Toiminnallisen opinnäytetyön aiheen idea lähti työelämän tarpeista. Opinnäytetyö kuuluu vuonna 2007 alkaneeseen hankkeeseen ”Työikäisen sydänpotilaan ja hänen perheensä sekä hoidonantajan ohjaaminen”. Työelämän yhteistyökumppaneina tässä työssä olivat HYKS:n Sydän- ja keuhkokeskuksen Kardiologian poliklinikan sairaanhoitajat. Teoreettisen osan muodostivat näyttöön perustuva tieto sydänpotilaan terveysvalmennuksesta, suuhygienistin osaamisesta sydänpotilaan hoidossa sekä suun ja sydämen terveyden vastavuoroisesta yhteydestä. Työn vaiheita olivat opintokäynnit, yhteiskehittelyt ja animaation tuottaminen yhdessä Metropolia Ammattikorkeakoulun viestinnän koulutusohjelman opiskelijoiden kanssa. Animaation ydinsisältö muodostui suun omahoidon ohjeista ja sen merkityksestä sydänterveydelle. Animaatio lanseerattiin Kardiologian poliklinikalla sairaanhoitajien koulutustilaisuudessa sekä sydänpotilaiden suun omahoidon ohjaustuokioissa. Opinnäytetyössä tuotettua materiaalia voi hyödyntää sydänpotilaiden hoitotyössä ja alan ammattilaisten koulutustilaisuuksissa. Yhteistyön Kardiologian poliklinikan sairaanhoitajien ja suuhygienistiopiskelijoiden kanssa tulisi olla jatkuvaa.Proper oral health increases heart patients’ quality of life. A healthy mouth is a part of human general health and it plays an important role in overall well-being. Oral diseases may have adverse effects on the general health, such as the prognosis of a treatment of a heart patient. Prevention of heart patient’s oral diseases is essential and it is done by increasing heart patients’ and nurses’ knowledge of oral health. The focus of this thesis was on strengthening the nurses’ and heart patients’ knowledge concerning the association between oral and heart health on the Cardiology Clinic. The aim was to produce an animation about oral health in order to help nurses in the treating heart patients. The idea of this functional thesis was based on the needs of the working life and it is a part of the "Guiding of a Working-age Heart Patient and His/Her Family Members and Care Givers" project started at 2007. The nurses of the Cardiology Clinic of the Heart- and Lung Centre of the Helsinki University Central Hospital (HUCH) represented co-operative partners of the working life. The theoretical part of the work consisted of performance based knowledge about health training of a heart patient, dental hygienist’s know-how in the treatment of a heart patient, and reciprocal relationship between oral and heart health. Learning visits, development processes, and producing of the animation together with the Metropolia University of Applied Sciences‘ media students were included to the work. The core content of the animation was formed on the advice of oral self-care and its significance to heart health. The animation was launched on the Cardiology Clinic during a training day for nurses and during the advicing sessions of oral self-care for heart patients. The material produced may be beneficial in the treatment of heart patients and during training of the professionals. Co-operation between the nurses on the Cardiology Clinic and dental hygienist students should be continued

Carbon nanofiber- and alumina-reinforced lithium aluminosilicate for controlled thermal expansion materials

[EN] Materials with a very low or tailored thermal expansion have many applications ranging from cookware to the aerospace industry. Among others, lithium aluminosilicates (LAS) are the most studied family with low and negative thermal expansion coefficients. However, LAS materials are electrical insulators and have poor mechanical properties. Nanocomposites using LAS as a matrix are promising in many applications where special properties are achieved by the addition of one or two more phases. The main scope of this work is to study the sinterability of carbon nanofiber (CNFs)/LAS and CNFs/alumina/LAS nanocomposites, and to adjust the ratio among components for obtaining a near-zero or tailored thermal expansion. Spark plasma sintering of nanocomposites, consisting of commercial CNFs and alumina powders and an ad hoc synthesized beta-eucryptite phase, is proposed as a solution to improving mechanical and electrical properties compared with the LAS ceramics obtained under the same conditions. X-ray diffraction results on phase compositions and microstructure are discussed together with dilatometry data obtained in a wide temperature range (-150 to 450 degrees C). The use of a ceramic LAS phase makes it possible to design a nanocomposite with a very low or tailored thermal expansion coefficient and exceptional electrical and mechanical properties.This work was financially supported by the National Plan Projects MAT2006-01783 and MAT2007-30989-E and the Regional Project FICYT PC07-021. A Borrell thanks the Spanish Ministry of Science and Innovation for her research grant BES2007-15033. O Garcia-Moreno is working for CSIC under a JAE-Doc contract co-funded by the ESF.Borrell Tomás, MA.; Garcia-Moreno, O.; Torrecillas, R.; Garcia-Rocha, V.; Fernandez, A. (2012). Carbon nanofiber- and alumina-reinforced lithium aluminosilicate for controlled thermal expansion materials. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS. 1-7. doi:10.1088/1468-6996/13/1/015007S1