||The technological process and a
machine for centrifugal barrel polishing (CBP) of the RF surface of
single cell, two- and three cell cavities was developed. Influence of
technological parameters on the removal rate and surface quality is
investigated. Maximal removal rate of Nb layer is > 25 mum/h. The
highest accelerating gradient achieved on single cell cavities after
CBP, electropolishing and baking was Eacc = 36 - 38 MV/m with a quality
factor up to Q = 2.1*1E10. The single - point burnishing process of the
niobium surface by freely rotating ball is investigated. Influence of
the rotating speed, radial displacement of the ball, pressing force and
lubrication medium on the quality of burnished surface and possibility
to get a work hardened surface layer is explored on a flat niobium
samples. Burnishing experiments on the cavity cell curvature were done.
The roughness of the burnished surface is = 0.05...0.08 um, Rz =
0.2...0.3 um, Rmax = 0.2...0.3 um. The depth of the work hardened layer
is 2...10 um.