scholarly journals The Development of Materials for the Future Vacuum Technology. Austenitic Stainless Steel for Extream-High Vacuum.

1993 ◽  
Vol 32 (11) ◽  
pp. 801-802
Author(s):  
Takemi Yamada ◽  
Akira Tohyama
2011 ◽  
Vol 110-116 ◽  
pp. 600-605 ◽  
Author(s):  
A. Devaraju ◽  
A. Elayaperumal ◽  
S. Venugopal ◽  
Satish V. Kailas ◽  
J. Alphonsa

The tribological properties of Plasma Nitrided (PN) rings were examined in high vacuum environment (1.6 x 10-4bar) at 25°C, 200°C and 400°C. The high vacuum based pin on disc tribometer was used for this investigation. The two different sliders namely austenitic stainless steel type AISI 316LN (316LN) pin and Nickel based alloy coated (Colmonoy) pin have been used. The tribological parameters such as friction coefficient, wear mechanism and wear rate have been evaluated. The PN 316LN rings exhibits excellent wear resistance against 316 LN pin and Colmonoy pin at all temperatures. However, the PN 316LN ring vs Colmonoy pin pair shows better wear resistance than PN 316LN ring vs 316 LN pin pair. Whereas the untreated 316 LN ring vs 316 LN pin pair exhibits the combination strong adhesion and plastic deformation wear mechanism.


MRS Bulletin ◽  
1990 ◽  
Vol 15 (7) ◽  
pp. 18-22
Author(s):  
Alan R. Krauss

There are times when technological or scientific progress is blocked for want of a breakthrough in a key area, just as there appear to be instances of a problem and its solution emerging simultaneously and independently. Upon closer inspection, however, this latter happy state is usually the result of long, hard work by people who had the insight to develop a solution before their peers were aware of the existence of a problem. At the moment, there are a number of convergent events occurring in vacuum technology which in all likelihood will have as profound an effect as the development of ultrahigh vacuum (UHV) technology in the late 1960s and early 1970s. These developments may be viewed as challenges posed by the requirements of certain technologies, or as a series of breakthroughs which will lead to new opportunities. Materials and materials processing or coatings are the key factors in most of these new developments, just as new pump and seal designs, and new vacuum practice were responsible for the development of UHV (10−9–10−11 torr) technology.In particular, aluminum is emerging as a material which may replace stainless steel for applications where the ultimate in vacuum is required. By suitable treatment, pure aluminum and aluminum alloys can be made to produce static outgassing rates more than 10 times lower than stainless steel. Systems capable of reaching a base pressure in the extremely high vacuum (XHV) range of 10−12–10−13 torr, such as those described in this issue by H. Ishimaru, are now commercially available.


Author(s):  
R. Gonzalez ◽  
L. Bru

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.


Author(s):  
G. Fourlaris ◽  
T. Gladman

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.


2012 ◽  
Vol 53 (6) ◽  
pp. 1090-1093 ◽  
Author(s):  
Yasuhiro Hoshiyama ◽  
Xiaoying Li ◽  
Hanshan Dong ◽  
Akio Nishimoto

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