Paper VT-TuM13
Characterization Studies of UHV Polished Surfaces

Tuesday, November 8, 2016, 12:00 pm, Room 104C

Interest continues to remain high in the application of electropolished surfaces. Studies of outgassing and surface treatments dating back to 1969 have remained relevant as science continues to push the lower boundaries of UHV. [1-5] More recently, polished stainless steel surfaces have been tested for use in high voltage applications. [6] The stainless steel flanges must have excellent sealing capability in low compression UHV joints, be able to withstand temperatures above 1200^oC, increased corrosion resistance, and provide minimal outgassing.

A characterization study was performed comparing electropolished stainless steel flanges with plated and subsequently hand-polished stainless steel flanges to optimize the flange surface for temperature resistance, corrosion resistance, hermeticity, and outgassing. A randomized designed orthogonal experiment (full factorial) was performed varying the type of polish, the electrolytic exposure time, and post-polish processing temperature. Electroplished surface quality showed a strong interaction between the exposure time to the electrolytic bath and the post-process annealing temperature. Nickel electroplating followed by hand polishing showed resultant plating thickness inconsistencies along with an adverse effect at elevated temperatures.

References:

[1] J. R. Young, J. Vac. Sci. Technol. 6, (1969).

[2] N. Yoshimura, T. Sato, S. Adachi and T. Kanazawa, J. Vac. Sci. Technol. A 8, 924 (1990).

[3] K. Odaka and S. Ueda, J. Vac. Sci. Technol. A 13, 520 (1995).

[4] Y. Sasaki, J. Vac. Sci. Technol. A 25, 1309 (2007).

[5] P. Nunez, E. Garcia-Plaza, A. R. Martin, R. Trujillo and C. Dela Cruz, AIP Conf. Proc. 1181, 130 (2009).

[6] M. BastaniNejad, et. al., J. Vac. Sci. Technol. A 33, 041401 (2015).