Fabrication, Thermo-Mechanical Processing and Characterization of a Ti-6% Al-1.5% V-1.0 Mo-0.5% Zr-0.1% C Alloy with Addition of Ru and Modifications of Small Amounts of V and Mo

MRS Advances ◽  
2019 ◽  
Vol 4 (57-58) ◽  
pp. 3097-3104
Author(s):  
Bayron Santoveña ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra

ABSTRACTPseudo-α or near-α titanium alloys are being widely used in the power generation industry due to their stability at high temperature service, good mechanical characteristics and corrosion resistance. Particularly Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C alloy is mainly used in turbines components, heat exchangers and pipes for steam conduction, among others; these are subjected to critical conditions of temperature, abrasion and corrosive environments. A good performance of such devices depends on the chemistry and of the material processing story.Effects on microstructure and wear resistance with the addition of Ru and small variation of V and Mo amounts in the Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C alloy were analyzed. Three different alloys were melted in a vacuum induction furnace with a cooled copper skull under an argon protective atmosphere for this studyFour alloys were melted “Alloy 1” Ti-6% Al-1.5% V-1.0Mo-0.5% Zr-0.1% C-0.3% Ru, “Alloy 2” Ti-6%Al-0.5%V-1.6%Mo-0.5%Zr-0.1% C-0.3% Ru, “Alloy 3” Ti-6%Al-2.2%V-0.5%Mo-0.5%Zr-0.1%C-0.3%Ru. After melting, all alloys were homogenized at 1200°C for two hours, followed by hot rolling above β transition temperature with a reduction of 50% in thickness.All alloys were analyzed by using scanning electron microscopy (SEM) and Vickers Micro hardness (HV). Results shown that Mo and V variations modified the micro hardness by microstructure refinement. In contrast, the addition of Ru showed no microstructure modification.

2013 ◽  
Vol 197 ◽  
pp. 113-118 ◽  
Author(s):  
Wojciech Szkliniarz ◽  
Agnieszka Szkliniarz

In this paper, the microstructural characteristics of cast TiAl-based intermetallic alloy were conducted, indicating the average grain diameter and interlamellar spacing as the parameters that determine their functional properties. The possibilities of forming these parameters by changing the crystallisation conditions were also shown. Methods for acquisition of images as well as detection of grain boundaries and lamellar precipitations of phases, necessary in the measurement of stereological parameters of the microstructure of these alloys, were presented


2013 ◽  
Vol 197 ◽  
pp. 107-112
Author(s):  
Agnieszka Szkliniarz ◽  
Georg Jarczyk

This paper presents the microstructural characteristics of skull formed during melting of Ti-6Al-4V alloy with 0.5 wt% content of carbon in vacuum induction furnace using water-cooled copper crucible. The microstructure of ingot obtained as a result of skull melting is comprised of TiC carbides evenly distributed in the matrix, which consists of lamellar precipitations of α and β phases. The depth of carbon penetration towards the bottom skull was determined. At the plane section area of bottom skull, three clearly visible zones with diverse area fraction and sizes of carbides that occur in them were found. The effect of area fraction of carbides on hardness of individual zones at the bottom skull with reference to hardness of obtained ingot was also characterized.


2018 ◽  
Vol 768 ◽  
pp. 256-260
Author(s):  
De Zhen Meng ◽  
Guang Yao Chen ◽  
Ru Lin Zhang ◽  
Chong He Li

Y2O3doped SrZrO3(SZY) powders were prepared according to a solid-state reaction method, which the raw materials contains SrCO3, ZrO2and doped with 5 mol% Y2O3. And then the powders were used to make a green crucible shape by cold isostatic pressing. After that, the crucible was used to melt with TiNi alloy in the vacuum induction furnace with biscuit firing temperature of 900°C, and sintering temperature of 1750°C. The x-ray diffraction analysis (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to analysis the characterization of the Y2O3doped SrZrO3power; microstructure of the crucible at different holding time under the 1750°C and the interfacial reaction between the crucible and the TiNi alloy. The results showed that the powders of Y2O3doped SrZrO3were synthesized at 1200°C, and there was no obvious reaction layer and elements diffusion between the crucible and TiNi alloy. The ingot is easy to separate from the crucible after smelting.


2017 ◽  
Vol 3 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Alexander Brensing ◽  
Roman Ruff ◽  
Benjamin Fischer ◽  
Sascha L. Wien ◽  
Klaus-Peter Hoffmann

Abstract:The usability of flexible electrodes in moving environment is limited due to different mechanical characteristics of their metallic and polymeric components. To achieve structure compatible electrodes, all used materials need to have similar Young’s moduli as the surrounding tissue. This paper describes the characterization of macroscopic as well as miniaturized electrodes entirely made out of modified silicone (PDMS). Electrochemical, mechanical, biological, optical, and applicative methods were used. It could be shown, that PDMS electrodes are capable to be used for recording electrocardiograms with similar form and amplitude as with standard electrodes.


2005 ◽  
Vol 65 (2) ◽  
pp. 371-376 ◽  
Author(s):  
M. R. Vale ◽  
R. V. Pereira ◽  
S. M. Almeida ◽  
Y. M. Almeida ◽  
S. F. L. C. Nunes

Adenosine is an important signaling molecule for many cellular events. Adenosine deaminase (ADA) is a key enzyme for the control of extra- and intra-cellular levels of adenosine. Activity of ADA was detected in hemolymph of B. glabrata and its optimum assay conditions were determined experimentally. The pH variation from 6.2 to 7.8 caused no significant change in ADA activity. Using adenosine as a substrate, the apparent Km at pH 6.8 was 734 µmols.L-1. Highest activity was found at 37ºC. Standard assay conditions were established as being 15 minutes of incubation time, 0.4 µL of pure hemolymph per assay, pH 6.8, and 37ºC. This enzyme showed activities of 834 ± 67 µmol.min-1.L-1 (25ºC) and 2029 ± 74 µmol.min-1.L-1 (37ºC), exceeding those in healthy human serum by 40 and 100 times, respectively. Higher incubation temperature caused a decrease in activity of 20% at 43ºC or 70% at 50ºC for 15 minutes. The ADA lost from 26 to 78% of its activity when hemolymph was pre-incubated at 50ºC for 2 or 15 minutes, respectively. Since the ADA from hemolymph presented high levels, it can be concluded that in healthy and fed animals, adenosine is maintained at low concentrations. In addition, the small variation in activity over the 6.2 to 7.8 range of pH suggests that adenosine is maintained at low levels in hemolymph even under adverse conditions, in which the pH is altered.


2010 ◽  
Vol 65 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Thomas Harmening ◽  
Rainer Pöttgen

Samples of EuRu4B4 and of the new boride EuRuB4 were prepared from europium, RuB, and RuB4 precursor alloys, respectively, in sealed tantalum tubes in an induction furnace. EuRu4B4 crystallizes with the LuRu4B4 structure, a = 748.1(1), c = 1502.3(4) pm. The structure of EuRuB4 was refined on the basis of X-ray diffractometer data: Pbam, a = 599.7(1), b = 1160.7(3), c = 358.06(7) pm, wR2 = 0.0691, 474 F2 values, and 38 variables. The four crystallographically independent boron sites build up layers which consist of almost regular pentagons and heptagons which sandwich the ruthenium and europium atoms, respectively. Within the two-dimensional [B4] networks each boron atom has a slightly distorted trigonal-planar boron coordination with B-B distances in the range 172 - 186 pm. Temperature-dependent 151Eu Mössbauer spectra show stable trivalent europium for EuRu4B4 and EuRuB4


Metallurgist ◽  
1974 ◽  
Vol 18 (7) ◽  
pp. 526-527
Author(s):  
N. P. Pozdeev ◽  
Al. G. Shalimov ◽  
A. B. Sergeev ◽  
R. F. Maksutov ◽  
I. V. Khalyakin

2007 ◽  
Vol 23 ◽  
pp. 283-386
Author(s):  
Mariana Lucaci ◽  
Radu L. Orban ◽  
M. Lazarescu ◽  
Stefania Gavriliu ◽  
Magdalena Lungu ◽  
...  

Directional solidification techniques have been applied to produce Ni based intermetallic alloys with preferentially oriented columnar crystals extended along the complete length and parallel to the solidification direction. Enhanced ductility is expected from such alloys. In this paper we present the research results concerning the application of this technique to some complex Ni3Al- Fe-B alloys obtained from compacted mixtures of elemental powders. The corresponding master alloys have been obtained in a vacuum induction furnace by the known Exo-Melt process [1]. The directional solidification of these alloys was subsequently performed on cylindrical samples, at two solidification rates, 30 and 15 mm/h. The influence of the rate and composition used on the dimensional variations, densities, microstructure, constituent phases and lattice parameters, as well as on the surface chemical composition have been documented and are presented in the paper.


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