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1.
We consider the possibilities of surface hardening of zirconium and titanium alloys with conversion oxide-ceramic coatings.
These coatings have been produced by the method of plasma-electrolytic treatment in alkaline solutions. We have established
that the plasma temperature in discharge spark channels reaches (6–9) · 103 K. The thickness of the coatings is 100 to 120 and 30 to 40 μm, and their microhardness is ∼ 800 and ∼ 1000 MPa for zirconium
and titanium alloys, respectively. The functional properties of the coatings depend on the synthesis conditions, including
the electrolyte composition, the cathode and anode current densities, and also the treatment time. We have evaluated the thickness,
microhardness, and wear resistance of the coatings under conditions of dry friction and cavitation as well as their fatigue
strength and corrosion resistance. We have established that this treatment provides a high wear and corrosion resistance of
the alloys under study with insignificant decrease in their fatigue strength.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 2, pp. 117–124, March–April, 2006. 相似文献
2.
We investigate the kinetics of corrosion of α-, (α+β)-, and β-titanium alloys in aqueous solutions of hydrochloric acid. It
is shown that the process of dissolution obeys a parabolic law and is accompanied by the formation of an oxide (TiO2 rutile) film on the metal surface. We demonstrate that corrosion processes are intensified as the amount of the β-phase in
titanium alloy increases.
Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv,
Vol. 33, No. 3, pp. 112–115, May–June, 1997. 相似文献
3.
The effect of minor additions of As, Sb and P on phase distribution and corrosion behavior has been studied in brasses. The
alloys investigated were 60Cu–39Zn–1Pb, 48.95Cu–45Zn–5Pb–1Sn–0.05As, 48.90Cu–45Zn–5Pb–1Sn–0.05As–0.05Sb and 48.85Cu–45Zn–5Pb–1Sn–0.05As–0.05Sb–0.05P.
Immersion tests in 1% CuCl2 solution indicated that the addition of As improved corrosion resistance while the combined addition of As + Sb and As + Sb + P
was not beneficial. The hardness increased significantly with the addition of As, Sb and P. Microstructural observations indicated
an increase in β phase fraction in the As, Sb and P containing alloys. X-ray diffraction studies confirmed the formation of
intermetallic compounds in As, Sb and P containing alloys. Based on the microstructural observations, the intermetallic compounds
appear to be primarily precipitated in the β phase with As + Sb and As + Sb + P additions. The lower corrosion resistance
of the alloys 48.90Cu–45Zn–5Pb–1Sn–0.05As–0.05Sb and 48.85Cu–45Zn–5Pb–1Sn–0.05As–0.05Sb–0.05P has been related to increase
in β phase volume fraction and precipitation of intermetallic compounds in the β phase. 相似文献
4.
The effects of calcium and yttrium additions on the microstructure,mechanical properties and biocompatibility of biodegradable magnesium alloys 总被引:2,自引:0,他引:2
In this study, the effects of calcium (Ca) and yttrium (Y) on the microstructure, mechanical properties, corrosion behaviour
and biocompatibility of magnesium (Mg) alloys, i.e. Mg–xCa (x = 0.5, 1.0, 2.0, 5.0, 10.0, 15.0 and 20.0%, wt%, hereafter) and Mg–1Ca–1Y, were investigated. Optical microscopy, X-ray diffractometry
(XRD), compressive and Vickers hardness testing were used for the characterisation and evaluation of the microstructure and
mechanical properties. The in vitro cytotoxicity of the alloys was assessed using osteoblast-like SaOS2 cells. The corrosion
behaviour of these alloys was evaluated by soaking the alloys in simulated body fluid (SBF) and modified minimum essential
medium (MMEM) at 37 °C in a humidified atmosphere with 5% CO2. Results indicated that the increase of the Ca content enhances the compressive strength, elastic modulus and hardness of
the Mg–Ca alloys, but deteriorates the ductility, corrosion resistance and biocompatibility of the Mg–Ca alloys. The Y addition
leads to an increase in the ductility; but a decrease in the compressive strength, hardness, corrosion resistance and biocompatibility
of the Mg–1Ca–1Y alloy when compared to the Mg–1Ca alloy. Solutions of SBF and MMEM with the immersion of Mg–xCa and Mg–1Ca–1Y alloys show strong alkalisation. Our research results indicate that Mg–xCa alloys with Ca additions less than 1.0 wt% exhibited good biocompatibility, low corrosion rate as well as appropriate elastic
modulus and strength; whilst the Y is not a proper element for Mg alloys for biomedical application due to its negative effects
to the corrosion resistance and biocompatibility. 相似文献
5.
A. I. Khorev 《Materials Science》2006,42(5):620-626
We study the effect of alloying on the mechanical properties of welded joints and base metal of titanium alloys of the system
Ti-Al-Mo-V-Cr-Fe. We also formulate the theoretical aspects and principles of complex alloying of titanium alloys and the
theory of alloying of additive materials for the welding of α-, (α + β), and β-alloys. It has been shown that (α + β)-(VT23)
and β-(VT19) structural titanium alloys, developed on the basis of the proposed theory of complex alloying, provide high weight
efficiency of construction of present-day flying vehicles.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 5, pp. 45–50, September–October, 2006. 相似文献
6.
Structure and Properties of Aluminum Alloys Modified with Silicon Carbide by Laser Surface Treatment
H. V. Pokhmurs'ka M. M. Student N. R. Chervins'ka Kh. R. Smetana A. Wank T. Hoenig H. Podlesak 《Materials Science》2005,41(3):316-323
We study the structure and properties of AA6082 and AA7075 aluminum alloys modified with particles of SiC with the help of
a laser. It is shown that the wear resistance of alloys laser reinforced with SiC in the case of friction against an abrasive
wheel is 30–75 times higher than for nonmodified alloys. On the basis of the data of electrochemical investigations, it is
shown that, for AA7075 alloy, the influence of its structural heterogeneity on the variation of corrosion potentials decreases
as the corrosion activity of the medium increases. We measured the values of corrosion currents of the surfaces of alloys
in various corrosive solutions.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 3, pp. 34–40, May–June, 2005. 相似文献
7.
M. V. Ved’ T. O. Nenastina V. V. Shtefan T. M. Bairachna M. D. Sakhnenko 《Materials Science》2008,44(6):840-843
The influence of pH of electrolyte on the tungsten content and current efficiency of a Co–W coating is determined. We determine
the corrosion rates of Co–W and Ni–Pd alloys by the polarization resistance method and show that the coatings are classified
as belonging to highly corrosion-resistant coatings. The catalytic reactivity of coatings in a model reaction of hydrogen
release is assessed. Dependences of the corrosion resistance and catalytic reactivity of Co–W and Ni–Pd alloys on the contents
of the components are obtained, and their character is justified.
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 44, No. 6, pp. 89–92, November–December, 2008. 相似文献
8.
N. A. Bazeleva 《Materials Science》2006,42(5):691-697
We present the regression-analytic and regression models aimed at the evaluation of the corrosion losses of VT1-0 titanium
as a function of time and the coefficients of acceleration of corrosion depending on the concentration of oxalic acid and
temperature. It is shown that, in a 66% solution of ethylene glycol, oxalic acid intensifies the process of corrosion of VT1-0
titanium for concentrations higher than 0.1% due to the formation of complexes of the products of oxidation of titanium with
oxalate anions, especially at elevated temperatures.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 5, pp. 103–107, September–October, 2006. 相似文献
9.
M. R. Chuchman I. O. Ryabtsev H. M. Krutsan E. F. Perepl’otchykov A. I. Dyachuk R. M. Yurkevych 《Materials Science》2009,45(5):746-750
We study the corrosion, electrochemical, and corrosion–mechanical properties of deposited KKh30N6VSR cobalt-based, NKh15SR3
nickel-based, and Kh16N8S5 iron-based alloys in a standard NACE hydrogen-sulfide solution. It is shown that the deposited
Kh16N8S5 iron-based alloy is unsuitable for these conditions due to its low corrosion resistance and susceptibility to hydrogen-induced
cracking. The cobalt- and nickel-based alloys are suitable for the surfacing of the components of shutoff fittings of the
oil-and-gas extraction equipment. However, as far as the “operating characteristics–cost” ratio is concerned, the nickel-based
alloy outweighs the cobalt- based alloy. 相似文献
10.
We study specific features of the processes of phase formation and gas saturation in VT1-0, VT14, OT-4, and VT20 titanium
alloys held in a carbon-and-nitrogen-containing medium for 5 h at 1100°C. Depending on the type of alloy, the TiC
x
N
y
carbonitride phases of different compositions are formed on the metal surface under the indicated conditions. The analysis
of the corrosion and electrochemical behavior of alloys shows that the best protective properties are exhibited by the carbonitrides
formed on the surface of VT20 alloy (whose composition is close to equiatomic and the surface roughness is minimum).
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 4, pp. 59–65, July–August, 2005. 相似文献
11.
It is shown that vacuum heating prior to nitridation contributes to the formation of nitrided layers on a surface. The layers
adequately protect titanium alloys from corrosion in aqueous solutions of hydrochloric acid. Moreover, vacuum heating makes
it possible to perform effective nitridation at low temperatures.
Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv.
Vol. 34, No. 1, pp. 108–110, January–February, 1998. 相似文献
12.
Rosalbino F Macciò D Scavino G Saccone A 《Journal of materials science. Materials in medicine》2012,23(4):865-871
The nearly equiatomic Ni–Ti alloy (Nitinol) has been widely employed in the medical and dental fields owing to its shape memory
or superelastic properties. The main concern about the use of this alloy derives form the fact that it contains a large amount
of nickel (55% by mass), which is suspected responsible for allergic, toxic and carcinogenic reactions. In this work, the
in vitro corrosion behavior of two Ti–Nb–Sn shape memory alloys, Ti–16Nb–5Sn and Ti–18Nb–4Sn (mass%) has been investigated
and compared with that of Nitinol. The in vitro corrosion resistance was assessed in naturally aerated Ringer’s physiological
solution at 37°C by corrosion potential and electrochemical impedance spectroscopy (EIS) measurements as a function of exposure
time, and potentiodynamic polarization curves. Corrosion potential values indicated that both Ni–Ti and Ti–Nb–Sn alloys undergo
spontaneous passivation due to spontaneously formed oxide film passivating the metallic surface, in the aggressive environment.
It also indicated that the tendency for the formation of a spontaneous oxide is greater for the Ti–18Nb–5Sn alloy. Significantly
low anodic current density values were obtained from the polarization curves, indicating a typical passive behaviour for all
investigated alloys, but Nitinol exhibited breakdown of passivity at potentials above approximately 450 mV(SCE), suggesting
lower corrosion protection characteristics of its oxide film compared to the Ti–Nb–Sn alloys. EIS studies showed high impedance
values for all samples, increasing with exposure time, indicating an improvement in corrosion resistance of the spontaneous
oxide film. The obtained EIS spectra were analyzed using an equivalent electrical circuit representing a duplex structure
oxide film, composed by an outer and porous layer (low resistance), and an inner barrier layer (high resistance) mainly responsible
for the alloys corrosion resistance. The resistance of passive film present on the metals’ surface increases with exposure
time displaying the highest values to Ti–18Nb–4Sn alloy. All these electrochemical results suggest that Ti–Nb–Sn alloys are
promising materials for biomedical applications. 相似文献
13.
S. O. Firstov M. I. Kuz’menko L. D. Kulak A. V. Kotko O. Yu. Koval’ I. D. Horna 《Materials Science》2006,42(3):309-315
We study the influence of alloying with Al, Zr, and Si on the structure and mechanical properties (including the modulus of
elasticity) of cast and deformed alloys of the Ti-B system. It is shown that, by optimizing the compositions of titanium alloys
subjected to combined silicoboride hardening and additionally alloyed with aluminum, it is possible to get the modulus of
elasticity E as high as 160 MPa with a strength σ of 1500 MPa and a level of plasticity δ of 2–5% at room temperature.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 3, pp. 27–32, May–June, 2006. 相似文献
14.
We study new alloys of the Ti-Si-Al-Zr system. It is shown that the high-temperature and cyclic corrosion crack-growth resistances
of cast materials remain practically constant up to temperatures of 700–800°C and in a 3% NaCl solution (pH = 7), respectively.
Annealing and quenching from the (α + β)-and β-phase regions of Ti-4Si-5Al-5Zr cast alloy lead mainly to changes in the structure
of the matrix and do not improve its strength and cyclic crack-growth resistance in the investigated working media, except
the increase in the threshold of corrosion fatigue after treatment from the β-region and formation of a lamellar β-matrix.
The increase in the strength, plasticity, and cyclic crack-growth resistance of these alloys at room and high temperatures
is attained as a result of the formation of a globular structure of the matrix and silicide phase after thermomechanical treatment
with deformation of at least 90%.
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Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 3, pp. 45–56, May–June, 2006. 相似文献
15.
L. Krüger F. Tuchscheerer M. Mandel S. Müller S. Liebsch 《Journal of Materials Science》2012,47(6):2798-2806
In this study, the corrosion behaviour of several aluminium alloys in ethanol fuels was investigated by immersion and polarization
tests. The corrosion properties of cast aluminium alloys (Al–17wt%Si–4wt%Cu–Mg, Al–8wt%Si–3wt%Cu, Al–7wt%Si–Mg and Al–17wt%Si–4wt%Cu–Mg
with a chemically deposited nickel layer) in ethanol blended gasoline fuels were examined at various ethanol and water contents
and various temperatures. Electrochemical and gravimetric measurements revealed a pronounced acceleration of the corrosion
process above the boiling point. Additions of water restrain the corrosion. Increasing the ethanol content and the temperature
leads to a higher corrosion sensitivity of the aluminium alloys. Furthermore, the nickel layer is very protective in all tested
fuels. For aluminium alloys, a theory of the corrosion process in ethanol blended gasoline fuels is proposed. 相似文献
16.
We present the results of experimental determination of the character of damage to specimens having the shape of truncated
cones made of titanium VT14 and aluminum AMg6 alloys under impact loading and perform a numerical analysis of longitudinal
stresses at the sites of formation of rear cleavage cracks.
Translated from Problemy Prochnosti, No. 5, pp. 110–112, September–October, 1997. 相似文献
17.
We present a survey of the research and development of titanium alloys, mill products, processes, and applications in the
CIS between the tenth and eleventh Titanium World Conferences. Driven by an increased world-market demand, the titanium industry
of the CIS has become an important contributor to the global expansion of titanium in volume and applications. Unfortunately,
the domestic shipments of titanium and, especially of mill products, remain low because of the inadequate consumption of titanium
by domestic end-users, such as aerospace, chemical, and marine (shipbuilding) industries. Although the titanium-research activity
remains not as extensive as earlier, it is characterized by a certain recovery motivated by both performance-driven and cost-driven
applications. In numerous cases, the studies are performed through broad international cooperation. Due to its application-oriented
nature, these trends of activities are moving from academic institutions to industrial research groups. Hence, the fundamental
studies of the complex nature of titanium-based materials are gradually shifted to the applied research aimed at the development
and scaling up of advanced alloys, processes, and new applications. The “Titan” Interstate Association realizes an important
mission by keeping the titanium industry and science in the CIS united, coherent, and cooperative despite the disintegrative
political and economic trends in the countries of the former Soviet Union.
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 44, No. 3, pp. 7–20, May–June, 2008. 相似文献
18.
We study the influence of plasma-sprayed coatings with various chemical compositions and structures on the serviceability
of Ti−5.0 Al−2.0 Zr−3.0 Sn−2.0V titanium alloy under the conditions of fretting-fatigue fracture for console specimens. It
was discovered that, under the conditions of fretting fatigue, coatings made of powders of titanium and chromium carbides
slightly decrease the fretting fatigue limit. Coatings made of a powder of TS-8 (α+β)-alloy, a mechanical mixture of self-fluxing
alloys based on nickel (NiCrBSi), and tungsten carbides (WC) increase the endurance limit by 10–15%. At the same time, spraying
with plated (Ni)−(Al2O3) powders increases this quantity by 40% and even more. Voltammetric investigations does not reveal any correlation between
the corrosion electrochemical properties of coatings (corrosion currents and potentials) at 20°C and fretting fatigue durability
in a 3% aqueous solution of sodium chloride.
Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fizyko-Khimichna Mekhanika Materialiv,
Vol. 33, No. 3, pp. 72–76, May–June, 1997. 相似文献
19.
We study the influence of alloying of spongy titanium with oxygen on the structure, mechanisms of fracture, and mechanical
properties of titanium. It is shown that, within the range of concentrations 0.05–0.30%, oxygen insignificantly affects both
the structure and the mechanism of fracture of cast titanium but strongly increases its strength with preservation of plasticity
within the admissible range specified for standard titanium alloys of this grade.
Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 44, No. 3, pp. 78–80, May–June, 2008. 相似文献
20.
I. V. Oryshich 《Materials Science》2000,36(1):104-110
We present the results of investigations of chloride corrosion and oxidation of refractory éP539 and éP99 nickel-base alloys.
We established that the heat-resistance of these alloys is rather high up to a temperature of 1273 K, whereas, at a temperature
of 973 K, the chloride corrosion proceeds intensively and has an intercrystalline character. Under the same kinetic conditions,
the rate of chloride corrosion is greater than the rate of oxidation by two to three orders of magnitude. éP539 alloy is more
resistant against chloride corrosion than éP99 alloy by a factor of 1.1–1.3, but the heat-resistance of the former is less
than that of the latter by the same factor.
Frantsevich Institute for Problems of Materials Technology, Ukrainian National Academy of Sciences, Kiev. Translated from
Fizyko-Khimichna Mekhanika Materialiv, Vol. 36, No. 1, pp. 87–92. January–February, 2000. 相似文献