Bulk changes and structurization in solid-phase sintering of titanium–silicon powder mixtures

Abstract

UDC 621.762.5:620.18 Titanium-silicon powder materials produced by vacuum sintering of elementary powder mixtures containing up to 25 at.% Si are examined. The structurization of sintered materials with different compositions is studied. The bulk changes of samples in sintering depending on the content of the second component and sintering temperature are analyzed. The process conditions to produce materials of minimum porosity are determined.

Study of Ti-7.5Si-22.5B alloys produced by powder metallurgy

“…Cold isostatic pressing had not increased the densification of the latter sample. Probably, sintering temperatures below 1200°C are not high enough to promote high densities in the samples when compared to similar work 4 . Despite the similar densities of the compacts at lines 2 and 3 (Table 2), their hardness values are different due to variables as composition, particle size and contamination.…”

“…Analysis of thermomechanical treatments on composition, morphology and volume fractions of phases is fundamental to improve such development 1 . These titanium alloys have been used in structural applications at high temperatures and as a protective layer in drilling tools obtained through magnetron sputtering or other techniques [2][3][4] . Furthermore, Ti 5 Si 3 phase has high technological importance 5 , titanium borides present an excellent combination of properties 6,7 and there is limited information about the Ti 6 Si 2 B phase 8 .…”

“…Other research in this area shows that if the difference between sintering and eutectic *e-mail: brunobacci@yahoo.com.br melting temperatures is around only 50°C, part of the Ti-Si alloy is melted. At this condition, such melting partially ruins the silicide skeleton and shrinkages the liquid under capillary forces, which occurs due to the heat released from the silicide formation 4 . New methods for production of titanium alloys are necessary nowadays to reduce their costs and improve their properties.…”

Transformation of the Structure of the Sintered Aluminum Bronze with the Free Forging

“…Другим элементом структуры спеченной бронзы были поры с преобладанием узких вытянутых пор, расположенных в междендритных промежутках и крупных округлых пор со средним диаметром 30-50 мкм, образовавшихся на месте раство-рившихся частиц алюминия в меди. Такая структура типична для спеченных сплавов с одно-сторонней растворимостью легирующего элемента [4]. Микротвердость спеченного сплава в среднем составляла (700 ± 35) МПа.…”

Structure and Properties of a Coating (TiCuN) – Substrate (А7) System Modified with a High-Intenisty Electron Beam

“…A simultaneous use of metal and gas-discharge plasma sources allows the process of coating condensation to be performed in a plasma-assisted mode, which favors the formation of nanocrystalline (with the crystallite dimensions down to 1-10 nm) dense composite coatings exhibiting good adhesion to the substrate. The evaporated cathodes were Ti-Cu composite sintered cathodes, whose application shows promise in deposition of multi-component nanocrystalline coatings with enhanced physical-mechanical characteristics [7,8]. High-temperature processing of the surface layer under conditions of its melting was carried out using a high-intensity pulsed electron beam (SOLO facility, IHCE SB RAS), varying the electron beam energy density from 10 to 30 J/cm 2 , the electron beam pulse duration within 50-200 µs, and the number of pulses between 3-5.…”