Electrodeposition of Ni-B and Ni-Co-B Alloys by Using Boric Acid as Boron Source

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Corrosion-fatigue life of commercially pure titanium and Ti-6Al-4V alloys in different storage environments

Statement of problem. Removable partial dentures are affected by fatigue because of the cyclic mechanism of the masticatory system ansi frequent insertion and removal. Titanium and its alloys have been used in the manufacture of denture frameworks; however, preventive agents with fluorides are thought to attack titanium alloy surfaces.Purpose. This study evaluated, compared, analyzed the corrosion-fatigue life of commercially pure titanium and Ti-6Al-4V alloy in different storage environments.Material and methods. For each metal, 33 dumbbell rods, 2.3 mm in diameter at the central segment, were cast in the Rematitan system. Corrosion-fatigue strength test was carried out through a universal testing machine with a load 30% lon er than the 0.2% offset yield strength and a combined influence of different: environments: in air at room temperature, with synthetic saliva, and with fluoride synthetic saliva. After failure, the number of cycles were recorded, and fracture surfaces were examined with on SEM.Results. ANOVA and Tukey's multiple comparison rest indicated that Ti-6Al-4V alloy achieved 21,269 cycles (SD = 8,355) against 19,157 cycles (SD = 3,624) for the commercially purr Ti. There were no significant differences between either metal in the corrosion-fatigue life for dry specimens, but when the solutions were present, the fatigue life was significantly reduced, probably because of the product-ion of corrosion pits caused by superficial reactions.

Influência de tratamentos termo-mecânicos na estrutura e microestrutura da liga Ti-10%pNi obtida por fusão a arco

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of the substitutional solute on the mechanical properties of Ti-Nb binary alloys for biomedical use

Titanium alloys are widely used in the manufacture of biomedical implants because they possess an excellent combination of physical properties and outstanding biocompatibility. Today, the most widely used alloy is Ti-6Al-4V, but some studies have reported adverse effects with the long-term presence of Al and V in the body, without mentioning that the elasticity modulus value of this alloy is far superior to the bone. Thus, there is a need to develop new Ti-based alloys without Al and V that have a lower modulus, greater biocompatibility, and similar mechanical strength. In this paper, we investigated the effect of Nb as a substitutional solute on the mechanical properties of Ti-Nb alloys, prepared in an arc-melting furnace and characterized by density, X-ray diffraction, optical microscopy, hardness and elasticity modulus measurements. The X-ray and microscopy measurements show a predominance of the α phase. The microhardness values showed a tendency to increase with the concentration of niobium in the alloy. Regarding the elasticity modulus, it was observed a nonlinear behavior with respect to the concentration of niobium. This behavior is associated with the presence of the α phase.

On Ti-18Si-6B and Ti-7.5Si-22.5B powder alloys prepared by high-energy ball milling and sintering

Recently, a new ternary phase was discovered in the Ti-Si-B system, located near the Ti6Si2B composition. The present study concerns the preparation of titanium alloys that contain such phase mixed with α-titanium and other intermetallic phases. High-purity powders were initially processed in a planetary ball-mill under argon atmosphere with Ti-18Si-6B and Ti-7.5Si-22.5B at. (%) initial compositions. Variation of parameters such as rotary speed, time, and ball diameters were adopted. The as-milled powders were pressureless sintered and hot pressed. Both the as-milled and sintered materials were characterized by X-ray diffraction, scanning electron microscopy and energy-dispersive spectrometry. Sintered samples have presented equilibrium structures formed mainly by the α-Ti+Ti6Si2B+Ti5Si3+TiB phases. Silicon and boron peaks disappear throughout the milling processes, as observed in the powder diffraction data. Furthermore, an iron contamination of up to 10 at. (%) is measured by X-ray spectroscopy analysis on some regions of the sintered samples. Density, hardness and tribological results for these two compositions are also presented here.

Laska a smrt; tragedie o pěti jednáních.

At head of title: Dramaticka díla Jaroslava Vrchlického. XVIII.

Improved of Cr-Ni-Mo iron base alloys by vacuum melting and casting. Final report.

"Bureau of Ships, Department of the Navy. Contract no. NObs-77019, Index Number NS-013-119."

Extrauagantes viginti Ioannis vigesimisecundi vna cum elega[n]ti apparatu domini zenzelini de cassanis ..., necnon regulis Cancellarie et decsionibus rote e pluribus Iacobi Fontani ... Adiecte sunt praetera vtilissime apostille D. Francisci de pauinis in easdem extrauagantes cum glosa dicti d[omi]ni zenzelini, quibus succesit vita d[omi]ni Ioannis vigesimisecu[n]di ...

Mode of access: Internet.

Pami︠a︡ti M.I. Glinki. Po sluchai︠u︡ 50-tiliet-ni︠a︡go i︠u︡bilei︠a︡ "Ruslan i Li︠u︡dmila" 1842-1892. 27. noi︠a︡bria.

Mode of access: Internet.

Taʻlīqāt : ḥāshiyah li-baḥr al-ʻulūm wa-kanz al-maʻārif wa-al-fuhūm dhī al-janāḥayn fī ʻilmay al-ẓāhir wa-al-bāṭin Mawlānā Ḍiyāʼ al-Dīn al-Shaykh Khālid al-Baghdādī al-Sulaymānī al-ʻUthmānī ... ʻalá Ḥāshiyat Mawlānā al-Siyālkūtī ʻalá al-Khayālī.

Mode of access: Internet.

Investigation of the Ti-Al-Cb system as a source of alloys for use at 1200⁰-1800⁰F

"Materials Central, Contract No. AF 33(616)-6125, Project No. 7351."

Fatigue and stress rupture properties of Inconel 713C, V-57C and titanium alloys 7A1-3Mo-Ti and MST 821 (8A1-2Cb-1Ta-Ti)

"Materials Central, Contract No. AF 33(616)-6828, Project No. 7351."

Sbornik stateĭ v chestʹ Dmitrīi︠a︡ Aleksandrovicha Korsakova : po povodu sorokali︠e︡tīi︠a︡ ego uchenoĭ i pi︠a︡tidesi︠a︡tili︠e︡tīi︠a︡ ucheno-literaturnoĭ di︠e︡i︠a︡telʹnosti : istorīi︠a︡, istorīi︠a︡ literatury, arkheologīi︠a︡, i︠a︡zykovi︠e︡di︠e︡nīe filosofīi︠a︡, pedagogike = Mélanges Korsakoff : recueil de travaux, offert à M-r Dmitry Korsakoff, d-r et prof. émer. de l'Université de Kazan, à l'occasion du XL anniversaire de son professorat et de L ans d'activité comme savant et écrivain.

By D.V. Aĭnalov et al.

"Ėfemeridy" : statʹi po voprosamʺ iskusstva, teatra i literatuyry, kriticheskīe ėti︠u︡dy, literaturnye ocherki, nabroski, vpechatli︠e︡nīi︠a︡ /

With: Rystenko, A. V. (Aleksandr Vasilʹi︠e︡vich), 1881?-1915. Skazanīe o dvi︠e︡nadt︠s︡ati snakhʺ t︠s︡ari︠a︡ Mamera : vʺ slavi︠a︡no-russkoĭ literaturi︠e︡ / A.V. Rystenko. Odessa : "Ėkonomicheskai︠a︡" tipografīi︠a︡, 1904. -- Nevskīĭ, V. A. (Vladimir Aleksandrovich). Khudozhestvennye vystavki i oznakomlenie shirokikh narodnykh mass s zhivopisʹi︠u︡ / V.A. Nevskiĭ. Kostroma : Sovetskai︠a︡ tipografii︠a︡, 1920. -- Vsepolʹskai︠a︡ revoli︠u︡t︠s︡īonnai︠a︡ partīi︠a︡ : ocherkʺ sovremennykhʺ stremlenīĭ vsepolʹskoĭ partīi / sostavilʺ Azʺ. Lʹvovʺ : Vʺ tipografīi Stavropigīĭskago Instituta, 1903. -- Gurko, Vasiliĭ Iosifovich, b. 1864. Borba truda i kapitala : ego neizbi︠e︡zhnyi︠a︡ posli︠e︡dstvīi︠a︡ / Generalʺ V. Gurko. Berlin : Wosroschednje Rossii/ Die Wiedergeburt Russlands, 1919. -- Samokvasov, D. (Dmitrīĭ), 1843-1911. Paskopki drevnikhʺ mogilʺ i opisanīe, khranenīe i izdanē mogilʹnykhʺ drevnosteĭ / D.I︠A︡. Samokvasova. Moskva : Sinodalʹnai︠a︡ Tipografīi︠a︡, 1908.