scholarly journals VACUUM-PLASMA PROPERTIES OF STAINLESS STEEL AFTER IMPACT OF COMBINED GLOW-MICROWAVE DISCHARGES IN ARGON ATMOSPHERE

2021 ◽  
pp. 50-56
Author(s):  
G.P. Glazunov ◽  
V.E. Moiseenko ◽  
S.M. Maznichenko ◽  
M.N. Bondarenko ◽  
A.L. Konotopskiy ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Glow Discharge ◽  
Vacuum Chamber ◽  
Microwave Plasma ◽  
Initial Conditions ◽  
Argon Atmosphere ◽  
Chamber Wall ◽  
Vacuum Plasma ◽  
Glow Discharges ◽  
Outgassing Rate

The experiments were carried out to determine the vacuum-plasma characteristics (mainly erosion and outgassing rate in a vacuum) of the stainless steel 12X18H10T before and after processing the walls of the vacuum chamber with the glow discharge and combined, glow-microwave plasma discharges in argon atmosphere. The current-voltage characteristics, the electron density and electron temperature were measured. It was observed that the discharge voltage in the combined regime is significantly lower than in glow discharges. In some modes, this voltage decrease can be up to 200 V. It was shown that erosion of stainless steel 12X18H10T in the combined discharges is 70 %, less than in the glow discharges. Measurements were made of the outgassing rate of 12X18H10T stainless steel with the thermal desorption probe in situ in the DSM-1 vacuum chamber. It was shown that cleaning the chamber wall by the glow discharge during 5 h leads to a decrease in the outgassing rate from 5.5·10-5 to 1·10-5 (Torr.l)/(s.cm2) . When the chamber wall is treated with GM discharge starting from nearly the same initial conditions the outgassing rate decreased to 3·10-6 (Torr.l)/(s.cm2). Spectral measurements of the plasma radiation of a glow and combined discharges show a decrease in the ratio of the peaks of argon ions and neutrals during the transition from a glow discharge to a combined one.

scholarly journals Development of Technology for Vacuum Surface Conditioning by RF Plasma Discharge Combined With DC Discharge

2021 ◽  
Vol 17 (4) ◽  
pp. 33-43
Author(s):  
Yurii Kovtun ◽  
Gennadiy Glazunov ◽  
Vladimir Moiseenko ◽  
Sergiy Maznichenko ◽  
Mikhaylo Bondarenko ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Glow Discharge ◽  
Radio Frequency ◽  
Vacuum Chamber ◽  
Rf Discharge ◽  
Rf Plasma ◽  
Steel 12Kh18n10t ◽  
Basic Part ◽  
Surface Conditioning ◽  
Dc Discharge

Introduction. It is important to decrease light and heavy impurities influxes towards the plasma volume during the high temperature plasma experiments in fusion devices. This is why the conditioning of the wall inner vacuumsurfaces is a basic part of the fusion device operation.Problem Statement. The conventional inner vacuum chamber surface conditioning methods has a significant drawback: sputtering materials in a vacuum chamber. The inner vacuum surfaces can be also conditioned with radio-frequency (RF) discharge plasma, but the conditioning effectiveness is limited by low ion energy.Purpose. The purpose of this research is to develop vacuum surface conditioning technology by the radio frequency plasma combined with DC discharge. Materials and Methods. The noncontact passive method of optical plasma spectroscopy has been used to estimate ion plasma composition. The stainless steel outgassing has been determined in situ with the thermodesorption probe method. The sputtering of the samples has been measured with the weight loss method.Results. The studies of combined discharge have shown that: the anode voltage of combined discharge is lower than in case of the glow discharge; the stainless steel 12Kh18N10T erosion coefficient is about 1.5 times less in thecase of combined discharge than in the glow one; the thermal desorption diagnostic of wall conditions in the DSM-1 has shown better efficiency with the combined discharge as compared with the glow discharge. Theproposed technology is an original one and has no analogs.Conclusions. The reported research results have shown good prospects for the combined discharge usage for plasma walls conditioning and opportunities for using the combined discharge technology for big fusion machines.

Pump-down characteristics of outgassed clean stainless steel vacuum chamber and surface analysis of the chamber wall

Vacuum ◽  
1996 ◽  
Vol 47 (6-8) ◽  
pp. 727-731 ◽  
Author(s):  
Y Hirohata ◽  
A Mutoh ◽  
T Hino ◽  
T Yamashina ◽  
T Kikuchi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Analysis ◽  
Vacuum Chamber ◽  
Chamber Wall

Phase Studies in WC-Stainless Steel AISI 347 Hardmetal System with Graphite Addition

2014 ◽  
Vol 1024 ◽  
pp. 239-242
Author(s):  
Zuhailawati Hussain ◽  
Emee Marina Salleh ◽  
Tran Bao Trung ◽  
Zainal Arifin Ahmad
Keyword(s):  
Stainless Steel ◽  
Powder Mixture ◽  
Milled Powder ◽  
Graphite Powder ◽  
Planetary Mill ◽  
Argon Atmosphere ◽  
Maximum Hardness ◽  
Steel Container ◽  
Steel Aisi ◽  
Stainless Steel Aisi

In this study, WC-stainless steel AISI 347 hardmetal system was produced to replace WC-Co hardmetal which uses the expensive, toxic and depleted resource Co. WC, stainless steel AISI 347 and graphite powder mixture were milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Carbon was added in amounts ranging from 0 wt% until 4 wt% into the composition to avoid unwanted η (Fe3W3C) phase. As-milled powder was compacted at 300 MPa and sintered in a tube furnace at 1350°C. ɳ phase was detected in compositions with 0 and 1 wt% C addition. For 2 wt% C addition, no η (Fe3W3C) phase formation was identified. However, the η phase was detected for compositions containing 3 and 4 wt% C. Maximum hardness was achieved due to the absence of η phase.

Effects of Sintering Variables on the Physical and Mechanical Properties of Metal Injection Molding Molded 17-4 PH Stainless Steel

2021 ◽  
Vol 1028 ◽  
pp. 403-408
Author(s):  
Apang Djafar Shieddieque ◽  
Shinta Virdhian ◽  
Moch Iqbal Zaelana Muttahar ◽  
Muhammad Rafi Muttaqin
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Injection Molding ◽  
Relative Density ◽  
Physical And Mechanical Properties ◽  
High Hardness ◽  
Argon Atmosphere ◽  
Metal Injection Molding ◽  
Manufacturing Method ◽  
Small Complex

Metal injection molding (MIM) is a near net shape manufacturing technique for producing small, complex, precision parts in mass production. MIM process is manufacturing method that combines traditional shape-making capability of plastic injection molding and the materials flexibility of powder metallurgy. The process consists of the following four steps: mixing of metal powder and binder, injection molding to shape the component, debinding to remove the binder in the component, sintering to consolidate the debound parts. In this research, the physical and mechanical properties of metal injection molded 17-4 PH stainless steel were investigated with the variation of sintering temperatures (1300 °C - 1360 °C) and atmosphere conditions (argon and vacuum conditions). The relative density, microstructure, distortion, and hardness are measured and analyzed in this study. The results show that highest relative density of 87%, relative homogeneous shrinkage and high hardness are achieved by sintering at 1360 °C for 1.5 hours and argon atmosphere. At the same sintering temperature and time, sintering in vacuum shows lower relative density (81%) than that in argon condition due to pores growth. The pore growths were not observed in the argon atmosphere. It can be concluded that sintering stages more rapidly under vacuum condition. The hardness measurements result also showed that high hardness is obtained by high density parts. The optimum average hardness obtained in this study is 239 HV. However, the hardness properties results are still lower than 280 HV according to MPIF Standard 35 for MIM parts.

scholarly journals HELIUM RELEASE FROM 12Cr18Ni10Ti STAINLESS STEEL AFTER IMPACT OF STEADY STATE GLOW DISCHARGE He PLASMA

2021 ◽  
pp. 32-36
Author(s):  
G.P. Glazunov ◽  
M.N. Bondarenko ◽  
A.L. Konotopskiy ◽  
I.E. Garkusha ◽  
S.M. Maznichenko ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Steady State ◽  
Glow Discharge ◽  
Thermal Desorption ◽  
Gas Discharge ◽  
Plasma Pressure ◽  
Discharge Voltage ◽  
Probe Surface ◽  
Physical Mechanisms ◽  
He Atom

The thermal desorption experiments were carried out to study the process of helium outgassing from the stainless steel 12Cr18Ni10Ti after exposure to a steady state glow discharge (GD) plasma in He atmosphere. The currentvoltage characteristics in different plasma regimes have been measured and estimation of He ions energy has been made. Measurements of He release from the stainless steel probes showed the saturation of probe surface with He after the fluencies of ~ 4 ∙ 1019 ion/cm2. The value of He outgassing strongly depends on the regime of GD plasma: pressure of work gas, discharge voltage, etc. Several maximums, including the maximum at the temperature of 100…150 °C, were registered in the He desorption curves that indicated different He atom states on the surface and in the nearest surface bulk. Physical mechanisms of such He outgassing are discussed.

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