Yuichi Ikuhara, Takahisa Yamamoto, Akihide Kuwabara, Hidehiro Yoshida and Taketo Sakuma2001-01-01Science and Technology of Advanced Materials
The addition of glass phase can control the grain boundary structure and hence the mechanical properties of tetragonal zirconia polycrystals (TZP). To reveal the effect of the glass dopant on the high-temperature deformation behavior of TZP, SiO2-doped TZP, (SiO2–Al2O3)-doped TZP, (SiO2–MgO)-doped TZP and undoped TZP…
Guimarães V.A.、Hein L.R.O.、Zangrandi Filho J.2001-01-01Materials Research
Fracture toughness testing becomes a very important parameter for mechanical design and maintenance of parts and structures. This work presents the design and construction of a machine device to perform the pre-crack nucleation on SE(B) specimens for fracture toughness testing. Employing this device, it is possible to…
Célia Marisa Rizzatti-Barbosa、Marco Aurélio Fraga、Tarcísio de Moraes Gonçalves2001-01-01Materials Research
The purpose of this work was to analyze water sorption by polymerized acrylic resins under different pressure, temperature and time treatments. A thermo-cured acrylic resin was used as the denture base (Classico Ltda.) and ethylene glycol di-methacrylate as a cross-linking agent, with processing carried out in a water…
Marcello Filgueira、José Nilson F. de Holanda、Ruben Rosenthal 等 4 位作者2001-01-01Materials Research
Cu-Nb microcomposites are attractive in magnet pulsed field technology applications due to their anomalous mechanism of mechanical strength and high electrical conductivity. In this sense, recently it was conceived the use of Cu 15% vol. Nb wires to operate as a high tensile strength cable for a diamond cutting tool (…
Nassar Eduardo J.、Serra Osvaldo A.、Calefi Paulo S. 等 5 位作者2001-01-01Materials Research
Silica gel was functionalised with chloropropyl groups through the sol-gel process and then a beta-diketone was incorporated into the support. Afterwards, Eu3+ ion and its chelates of 1,10-phenantroline (phen) and 2,2'-bipyridine (bpy), red phosphors, were supported on such silica. Luminescence studies of Eu3+ bound t…
Machado Giovanna、Luca Maria Augusta de、Samios Dimitrios2001-01-01Materials Research
We evaluate the orientation of microstructural elements of isotatic polypropylene (i-PP) before and after deformation using computerized "Quantikov" software analysis of Scanning Electron Microscopy (SEM) images. We observed that before deformation through uniaxial compression, the polymeric material doesn?t exhibit a…
R.G. Mendes、E.B. Araújo、J.A. Eiras2001-01-01Materials Research
Strontium barium niobate (SBN) thin films of good quality were deposited on Pt/Ti/SiO2/Si substrate using a polymeric resin containing metallic ions. Films were crystallized at different temperatures and for different duration of time. The structure of these films was studied using X-ray diffraction. The coexistence o…
Maurício F. Gozzi、Eduardo Radovanovic、I. Valéria P. Yoshida2001-01-01Materials Research
Si3N4/SiC nanocomposite powders were obtained from a preceramic polymeric network based on poly(methylsilane) as the in situ quasi-stoichiometric SiC source. These powders were constituted of nanosized SiC particles homogeneously distributed in the Si3N4 particulate matrix. beta-SiC whiskers were grown at 1400 °C in t…
José A. da Rocha Filho、Erna E. Bach、Élcio R. Barrak 等 4 位作者2001-01-01Materials Research
Graft polymerization of N-vinyl-2-pyrrolidone with chitin was studied using hydrogen peroxide for initiation. The capacity of the obtained VP-g-Ch graft copolymer for adsorption of nickel was examined. The effect of temperature, pH and solute concentration on the chelating properties of the grafted and ungrafted chiti…
A.G. Tomba Martinez、A.L. Cavalieri2001-01-01Materials Research
Disks of a commercial alumina were fabricated by slip casting, calcination and sintering. The surfaces were machined using SiC papers (120 and 320 grit) and characterized by residual stresses measurements. The mechanical strength was determined in biaxial flexure (ball on discontinuous ring). The specimens were subjec…
Lourenço N.J.、Jorge Jr. A.M.、Rollo J.M.A. 等 4 位作者2001-01-01Materials Research
Dilatometric techniques were used to build the continuous cooling transformation (CCT) diagram for a medium carbon microalloyed steel; the microstructure and hardness were determined at different cooling rates. The mechanical behavior of the steel in the austenite field and at temperatures approaching austenite to fer…
Hiroaki Takadama, Hyun-Min Kim, Tadashi Kokubo and Takashi Nakamura2001-01-01Science and Technology of Advanced Materials
Bioactive Ti–6Al–4V alloy, which spontaneously forms a bonelike apatite layer on its surface in the body and bonds to living bone through this apatite layer, can be prepared by producing an amorphous sodium titanate on its surface by NaOH and heat treatments. In this study, the process of apatite formation on the bioa…
Zanotto Edgar Dutra2001-01-01Materials Research
A.R.V. Benvenho、I.A. Hümmelgen2001-01-01Materials Research
An effective positive charge carrier mobility of 4.4 x 10 -9 cm²/V.s was directly determined using analytical expressions for space-charge-limited current in poly(1,10-decanedioxy-2-methoxy-1,4-phenylene-1,2-ethenylene-3,6-dimethoxy- 1,4-phenylene-1,2-ethenylene-3-methoxy-1,4-phenylene), OPPVDBC, which is a soluble el…
Berton Marcos A.C.、Avellaneda César O.2001-01-01Materials Research
Thin solid films of CeO2-SnO2 (17 mol% Sn) and CeO2-SnO2:X (X = Li, C and Si) were prepared by the sol-gel route, using an aqueous-based process. The addition of Li, C and Si to the precursor solution leads to films with different electrochemical performances. The films were deposited by the dip-coating technique on I…
N. Stem、M. Cid2001-01-01Materials Research
Considering recent modifications on n-type highly doped silicon parameters, an emitter optimization was made based on one-dimensional models with analytical solutions. In order to get good accuracy, a fifth order approximation has been considered. Two kinds of emitters, homogeneous and non-homogeneous, with phosphorus…
Rita Aparecida Zoppi、Eliana Aparecida de Rezende Duek、Débora C. Coraça‐Huber 等 4 位作者2001-01-01Materials Research
Poly(L-lactic acid) (PLLA) and poly(ethylene oxide) (PEO) blends were prepared by mechanical mixture and fusion of homopolymers. Samples were submitted to in vitro degradation tests (immersion in a phosphate buffer solution with pH = 7.4 at 37 °C). Independently of the blend composition, PEO was dissolved after 14 day…
Bone Tissue Engineering MaterialsOrthopaedic implants and arthroplastybiodegradable polymer synthesis and properties
Edgar Dutra Zanotto2001-01-01Materials Research
Santos D.R. dos、Santos D.S. dos2001-01-01Materials Research
The crystallization processes for the amorphous metallic alloys Fe74B17Si2Ni4Mo3 and Fe86B6Zr7Cu1 (at. %) were investigated using X-rays diffraction measurements performed in-situ during Joule-heating, with simultaneous monitoring of the electrical resistance. We determined the main structural transitions and crystall…
Walman Benício de Castro、Manuel de Lucena Maia、Claudio Shyinti Kiminami 等 4 位作者2001-01-01Materials Research
Melt undercooling opens new solidification pathways for non-equilibrium phases and non-conventional microstructures. Several techniques, including the fluxing technique, have been developed in order to reduce nucleation sites and to produce high undercoolings for metals and alloys. In this work the fluxing technique w…