scholarly journals Ion beam technology for the resource enhancement of responsible parts of a high speed friction unit

2021 ◽  
Vol 2131 (4) ◽  
pp. 042014
Author(s):  
L Krivina ◽  
I Tsareva ◽  
Yu Tarasenko

Abstract The needles from carbon steel “U10”, a details of high speed couple of friction “needle-thrust plate” of the gas centrifuge is investigated, in the initial, post-operational state and after irradiation by C+ ions different doses on the pulse-frequency “Raduga” accelerator. The purpose of this study is to increase the operability and service life of the responsible friction unit of the gas centrifuge. This purpose is achieved by mod-ification of the working sliding surface of the needle (which is a responsible part of the high-speed friction pair “needle-thrust plate”) by the pulse-frequency implantation with carbon ions. The dose of implantation (1018 cm−2 of C+ ions), was established, at which an optimal combination of mechanical and tribological properties of the working surface is achieved, which provides wear resistance increase during the operation of the friction pair. This method of surface treatment is recommended to use in case of operation of couple of friction “needle-thrust plate” for the purpose of increase in working capacity and a resource of operation of high speed couple of friction of the gas centrifuge.

2020 ◽  
Vol 5 ◽  
pp. 11-23
Author(s):  
G.V. Potemkin ◽  
◽  
O.K. Lepakova ◽  
V.D. Kitler ◽  
M.V. Zhidkov ◽  
...  

The phase and elemental composition of the near-surface layer of nitrided ferrovanadium irradiated with a high-power ion beam has been investigated by XRD and SEM methods. The impact of a powerful beam of the Temp-4M setup with an energy of carbon ions of 250 keV at a radiation pulse duration 10–7 s and a power density of charged particles qi ≥ 106 W/cm2 causes melting of the Fe-VN composite and partial evaporation of elements with a high vapor pressure from the surface layer. High-speed solidification of the melt on the surface of the Fe-VN target leads to the formation of highly dispersed vanadium nitride and tetragonal carbide Fe23C6 in the modified layer. After irradiation of Fe-VN with a high-power beam with qi ≈ 107 W/cm2 at a dose of ~ 1015 cm–2, a violation of the translational invariance of the distribution of intercalated carbon atoms, a structural redistribution of Fe and V atoms, and the formation of X-ray amorphous microliquations of Fe-V and gas-carbon complexes are observed in the modified layer.


2003 ◽  
Vol 82 (8) ◽  
pp. 1281-1283 ◽  
Author(s):  
N. W. Liu ◽  
A. Datta ◽  
C. Y. Liu ◽  
Y. L. Wang

1991 ◽  
Vol 235 ◽  
Author(s):  
D. K. Sood ◽  
V. C. Nath ◽  
Yang Xi

ABSTRACTAmorphisation of sintered SiC by bombardment with self (C, Si) ions has been studied. Ion doses ranged from 1×1015 to 1×1017 ions/cm2; and ion energy was varied from 0.09 to 5 MeV. Amorphisation was detected by micro-focus Raman scattering. Tribomechanical properties-friction and wear were studied with a high precision pin (steel ball) and disc (implanted) machine. Results show substantial improvements in friction and wear, which persist to a large number of cycles. Tribomechanical properties are shown to correlate with surface amorphisation and carburisation. Carbon ions are found to be much more effective than Si ions (with similar damage distributions) in reducing friction and wear.


1991 ◽  
Vol 239 ◽  
Author(s):  
Fred M. Kimock ◽  
Alex J. Hsieh ◽  
Peter G. Dehmer ◽  
Pearl W. Yip

ABSTRACTWe report on a recently commercialized Diamond-Like Carbon (DLC) coating that has been deposited on polycarbonate at near room temperature, via a unique ion beam system. Aspects of high speed impact behavior, chemical resistance, abrasion resistance, and thermal stability of the coating are examined. Results of scanning electron microscopy studies indicate that adhesion of the DLC coating is very good; no delamination of the coating was found on ballistically tested specimens. The well-bonded DLC coating did not cause the impact performance of polycarbonate to become brittle. Chemical exposure test results show that the DLC coating is capable of protecting polycarbonate from chemical attack by aggressive organic liquids. These ion beam deposited DLC coatings have considerable potential as protective coatings for optical systems.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Shi ◽  
Miao Li ◽  
Weihua Ma ◽  
Kang Chen

A new lateral coupling structure with independently rotating wheels (IRW) is proposed, and longitudinal creepage is obtained by replacing the gear pair with the friction pair to synchronize the rotation speed of left and right wheels. The auxiliary wheelset made up of two friction wheels can be placed either under the primary suspension or on the frame. Vehicles dynamics models with three different kinds of bogies are developed, including friction coupling bogie with independently rotating wheels (FCIRW-bogie), bogie with independently rotating wheels (IRW-bogie), and bogie with rigid wheelsets, and their guiding and resetting capability when negotiating large-radius curves are compared and analyzed. Results show that FCIRW has the advantages of both IRW and rigid wheelset. On the straight track, FCIRW has sufficient wheel-rail longitudinal creep force to assist the reset; its critical speed is much higher than that of the rigid wheelset. On the curved track, the whole vehicle wear power of FCIRW-bogie vehicle is about 2/3 of the rigid axle level.


2011 ◽  
Vol 10 (01) ◽  
pp. 135-142
Author(s):  
CHUNMEI ZHANG ◽  
YONGFENG LI

Thermal analysis can be used as one of the basis for the friction pair material selection in high-speed friction braking system. In this study, the experimental results showed that surface temperature could be reduced by increasing the radius of the friction disk or thermal conductivity coefficient of disk material with stable braking; In the early stage of long braking, the temperature on the friction surface rises rapidly, but further braking does not lead to a significant rise in temperature; In the case of short braking, there is not enough time for the friction surface to reach the critical temperature, and the disk surface reaches the maximum temperature at the end of braking. During long braking, the dimensionless time capacity of the friction surface reaching the highest temperature is F0 ≈ 0.1F0s.


2020 ◽  
Vol 93 (1107) ◽  
pp. 20190428 ◽  
Author(s):  
Oliver Jäkel

Proton and ion beam therapy has been introduced in the Lawrence Berkeley National Laboratory in the mid-1950s, when protons and helium ions have been used for the first time to treat patients. Starting in 1972, the scientists at Berkeley also were the first to use heavier ions (carbon, oxygen, neon, silicon and argon ions). The first clinical ion beam facility opened in 1994 in Japan and since then, the interest in radiotherapy with light ion beams has been increasing slowly but steadily, with 13 centers in clinical operation in 2019. All these centers are using carbon ions for clinical application. The article outlines the differences in physical properties of various light ions as compared to protons in view of the application in radiotherapy. These include the energy loss and depth dose properties, multiple scattering, range straggling and nuclear fragmentation. In addition, the paper discusses differences arising from energy loss and linear energy transfer with respect to their biological effects. Moreover, the paper reviews briefly the existing clinical data comparing protons and ions and outlines the future perspectives for the clinical use of ions like oxygen and helium.


Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 444 ◽  
Author(s):  
Hao Yang ◽  
Xiaojiang Li ◽  
Guodong Wang ◽  
Jianbang Zheng

Polycrystalline lead selenide material that is processed after a sensitization technology offers the additional physical effects of carrier recombination suppression and carrier transport manipulation, making it sufficiently sensitive to mid-infrared radiation at room temperature. Low-cost and large-scale integration with existing electronic platforms such as complementary metal–oxide–semiconductor (CMOS) technology and multi-pixel readout electronics enable a photodetector based on polycrystalline lead selenide coating to work in high-speed, low-cost, and low-power consumption applications. It also shows huge potential to compound with other materials or structures, such as the metasurface for novel optoelectronic devices and more marvelous properties. Here, we provide an overview and evaluation of the preparations, physical effects, properties, and potential applications, as well as the optoelectronic enhancement mechanism, of lead selenide polycrystalline coatings.


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