Correlation of outgassing of stainless steel and aluminum with various surface treatments

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578617· OSTI ID:6293405

Dylla, H F ^[1]; Manos, D M ^[2]; LaMarche, P H ^[3]

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1. Continuous Electron Beam Accelerator Facility, Newport News, Virginia 23606 (United States)
2. Department of Physics, College of William and Mary, Williamsburg, Virginia 23185 (United States)
3. Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

A number of important applications of ultrahigh vacuum technology involve the use of vacuum systems which cannot be baked [ital in] [ital situ], e.g., materials processing equipment and various designs of accelerators and fusion devices. A choice of vessel material and surface treatment which minimizes outgassing in unbaked systems has obvious advantages. We report on a systematic comparison of outgassing measurements from type 304 stainless steels and type 6061/63 aluminum alloys after various standard and advanced surface treatments. Correlations were made with high-resolution secondary ion mass spectroscopy and x-ray photoelectron spectroscopy profiles of the passivation oxide layer and profilometry measurements of the surface roughness. The observed outgassing rates [ital Q] obeyed a power law [ital Q]=[ital Q][sub 0][ital t][sup [minus][ital n]] where [ital n] varied from 0.94 to 1.27. Over the standard observation period (50 h), the outgassing was dominated ([gt]85%) by H[sub 2]O. The absolute outgassing rates varied by only a factor of 2.8 for the stainless steels and by a factor of 1.4 for the aluminum alloys, even though the surface roughness differed by more than two orders of magnitude. The high-value-added surface treatments (i.e., electropolishing) did not have significantly lower outgassing in comparison to simple detergent washes.

• OSTI ID: 6293405
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 11:5; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
ALLOYS
ALUMINIUM ALLOYS
DEGASSING
SURFACE TREATMENTS
ULTRAHIGH VACUUM
VACUUM SYSTEMS