Influence of ion treatment modes on the physical and mechanical properties of zirconia ceramics

2020 ◽  
Vol 10 ◽  
pp. 5-18
Author(s):  
S. А. Ghyngаzоv ◽  
◽  
V. А. Коstеnко ◽  
A. K. Khassenov ◽  
◽  
...  

The article considers the influence of the treatment modes by N2+ and Ar+ ions beams on the physical and mechanical properties of zirconia ceramics. Surface modification of zirconia ceramics was performed using two modes of ion treatment — pulsed and continuous. The pulse mode of treatment by N2+ ions was realized at an accelerating voltage of 250 – 300 kV, current density j = 150 – 200 A/cm2, and energy density W = (3.5 and 5) ± 5 % J/cm2. The continuous mode of treatment by Ar+ ions was realized at an accelerating voltage of 30 kV and an ion current density of 300 and 500 μA/cm2. The fluence of the Ar+ ion beam varied from 1016 to 1018 cm–2. It is established that the pulsed mode of ion treatment leads to the melting and recrystallization of the surface of ceramics. It is shown that this treatment leads to a violation of the oxygen stoichiometry in ceramics and, as a result, there is an appearance of electrical conductivity in the near-surface layers, the layers of zirconia ceramics become conductive. It was established that the continuous mode of ion treatment does not lead to the melting and recrystallization of the ceramics surface, but is accompanied by its slight etching. It is shown that under the action of continuous ion treatment, microhardness increases (by 14 %). Hardening of the surface layers of ceramics is observed at a depth that exceeds the average projected range of Ar+ ion by 103 times.

1994 ◽  
Vol 339 ◽  
Author(s):  
V. Heera ◽  
R. Kögler ◽  
W. Skorupa ◽  
J. Stoemenos

ABSTRACTThe evolution of the damage in the near surface region of single crystalline 6H-SiC generated by 200 keV Ge+ ion implantation at room temperature (RT) was investigated by Rutherford backscattering spectroscopy/chanelling (RBS/C). The threshold dose for amorphization was found to be about 3 · 1014 cm-2, Amorphous surface layers produced with Ge+ ion doses above the threshold were partly annealed by 300 keV Si+ ion beam induced epitaxial crystallization (IBIEC) at a relatively low temperature of 480°C For comparison, temperatures of at least 1450°C are necessary to recrystallize amorphous SiC layers without assisting ion irradiation. The structure and quality of both the amorphous and recrystallized layers were characterized by cross-section transmission electron microscopy (XTEM). Density changes of SiC due to amorphization were measured by step height measurements.


2018 ◽  
Vol 781 ◽  
pp. 70-75
Author(s):  
Sergei Ghyngazov ◽  
Valeria Kostenko ◽  
Sergey Shevelev ◽  
Anatoliy I. Kupchishin ◽  
Aleksey Kondratyuk

The effect of ion irradiation on the strength characteristics of magnesium oxide and ceramics based on zirconia is studied. The MgO samples were a single crystal grown in an artificial manner. Samples of zirconium ceramics were prepared by ceramic technology. Irradiation of MgO crystals was carried out by Si+ ions (E = 150 keV), Fe+ (E = 70 keV), C+ (E = 50 keV) at room temperature. The fluence varied within the range (1016–1017) сm–2. The modification of the investigated types of ceramics was carried out by ions Al+ (Е = 60 keV), Ar+ (Е= 60 keV), N+ (E = 50 keV). We used ion beams of microsecond duration and moderate power (the current density in the pulse was 3 10-3 A/cm2). Fluence was 1017 cm-2. The irradiation of the ceramics with an ion beam C+ (E = 50 keV) was also performed with nanosecond duration (τ = 50 ns). It is established that ionic irradiation of magnesium oxide leads to an increase in crack resistance and a critical stress intensity factor. Irradiation of ceramics leads to hardening of its near-surface layers.


2017 ◽  
Vol 81 (3) ◽  
pp. 360-364 ◽  
Author(s):  
Y. I. Golovin ◽  
A. I. Tyurin ◽  
S. D. Victorov ◽  
A. N. Kochanov ◽  
A. A. Samodurov ◽  
...  

1994 ◽  
Vol 354 ◽  
Author(s):  
T. Fujihana ◽  
O. Nishimura ◽  
K. Yabe ◽  
H. Hayashi ◽  
M. Iwaki

AbstractA study has been made of the chemical composition and mechanical properties of Ti+-implanted Si3N4 surface layers. Implantation of 48Ti+ was performed with doses ranging from 10 to 1017 ions cm”2 at an energy of 150 keV, and at nearly room temperature. XPS was used to analyze the depth dependence of atomic fraction and chemical bonding states of Ti+-implanted layers. The near-surface hardness was measured by a Vickers hardness tester. The friction and wear properties were measured under unlubricated conditions at room temperature using a pin on disk-plane and a block on wheel-periphery configurations, in which the pin and wheel used were AISI1045 and ASTM Wl-9, respectively. Implanted Ti-atoms formed a gaussian distribution predicted by the range theory. At the average projected range, most of Ti-atoms existed as a metallic state and TiN bonding was also formed. Oxygen and carbon were found near the surface layers. In addition to the surface peak, O-atoms accumulated in front of the average projected range of Ti. Such O-atoms formed bonds of Si-oxides and Ti-oxides. Carbon existed as a graphitic state. With increasing a Ti dose, the near-surface hardness decreased, and the wear rate increased at the running-in stage having the high friction coefficient. The steady wear attributed to the stable friction coefficient appeared after the running-in stage, although such a stable stage was not observed for unimplanted Si3N4. The mechanism for the change in mechanical properties of Si3N4 induced by Ti+-implantation will be discussed in relation to XPS characteristics.


2016 ◽  
Vol 7 (6) ◽  
pp. 605-608
Author(s):  
Vadim Chayevski ◽  
Valerij Zhylinski

The parameters of electrolytic synthesis of Ni-P coatings on steel surface from sulfate-chloride electrolyte have been determinated. The Ni-P alloys consist of separate phases of Ni and Ni3P and solid solution of implementation on the basis of the FCC Ni lattice, when it was deposited from the electrolyte at current density to be more than 7 A/dm2. The coating was formed with continuous globular surface at current density of 5 A/dm2. The globular formations are the Ni3P phase. The obtained at current density of 9 A/dm2 coatings have maximum value of micro¬hardness 430 HV. Darbe buvo nustatyti Ni-P dangų ant plieno paviršiaus elektrolitinės sintezės (iš sulfatinio-chloridinio elektrolito) parametrai. Ni-P lydinių mikrostruktūrą sudaro atskiros Ni ir Ni3P fazės arba nikelio kietasis įterpimo tirpalas, turintis kubinę paviršiaus centruotą gardelę, kai dangos yra nusodinamos iš elektrolito, esant srovės tankiui daugiau negu 7 A/dm2. Kai srovės tankis yra daugiau negu 5 A/dm2, formuojasi ištisinis, rutulinio pobūdžio dangos paviršius. Rutulio formos darinius sudaro Ni3P fazė. Dangos, turinčios didžiausią mikrokietumo reikšmę 430 HV, gautos esant srovės tankiui 9 A/dm2.


Author(s):  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
S. M. Myers

Detailed finite-element modeling of nanoindentation data is used to obtain accurate mechanical properties of very thin films or surface-modified layers independently of the properties of the underlying substrates. These procedures accurately deduce the yield strength, elastic modulus, and layer hardness, and greatly increase the usefulness of indentation testing with very thin surface layers. Moreover, extraction of the effective Young’s modulus in the near surface region should enable mechanical damage studies on a small scale. This paper presents a brief overview of the procedures involved and illustrates them with He-implanted Ni.


1986 ◽  
Vol 29 (7) ◽  
pp. 621-624
Author(s):  
G. B. Kainer ◽  
V. M. Kuchumova ◽  
L. A. Kochanova ◽  
V. I. Savenko ◽  
N. P. Fedoseeva ◽  
...  

Author(s):  
V. V. Romanov ◽  
D. S. Daev ◽  
L. E. Chesalov ◽  
A. I. Poserenin

The Sergiev Posad polygon of the MGRI-RSGPU is located on the watershed of the Pazha and Torgosha rivers located on the southern slope of the Klinsky-Dmitrovsky ridge; geologically, the upper part of its section is composed of clay soils of Quaternary and Cretaceous age. The paper gives an analysis of the values of seismic, electrical and physical and mechanical properties of soils, as well as resistivity of water sources and reservoirs. Main methods of near-surface geophysics allow obtaining this information. The performed methods made it possible to specify the geological structure of the first 15 meters of the section, to refine the hydrogeological conditions of the test site, to determine the properties of the grounds as bases for buildings and structures. Also, the effect of the radioactive substance oonthe state of the underlying soils has been established by means of a specially prepared soil radiometer plate .


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