Vacuum pump components without conversion layers

Abstract

The invention relates to vacuum pump components without conversion layers that are made of valve metals and alloys thereof.

1 . Vacuum pump components without conversion layers, made of valve metals or their alloys, characterized in that their surfaces have a coating of at least one oxide and/or oxyfluoride of an element of the group consisting of boron, germanium, aluminum, magnesium, titanium, niobium, hafnium and/or zirconium and mixtures thereof, produced by electroplating and having a layer thickness within a range of from 5 to 50 μm. 
     
     
         2 . The components according to  claim 1 , including rotors, stators, stator disk halves, helical stages, housings and bearing shells. 
     
     
         3 . . The components according to  claim 1 , characterized in that said valve metal is selected from aluminum, magnesium, titanium, niobium and/or zirconium and their alloys. 
     
     
         4 . The components according to  claim 1 , characterized in that said coating consists of at least one oxide and/or oxyfluoride of the group consisting of aluminum, titanium and/or zirconium. 
     
     
         5 . The components according to  claim 1 , characterized in that the thickness of the surface coating is from 15 to 30 μm. 
     
     
         6 . A process for preparing vacuum pump components without conversion layers, made of valve metals or their alloys, that are produced by electroplating, characterized by
 (a) providing an anodizing solution containing, in addition to water, at least one other component selected from the group of water-dispersible complex fluorides and oxyfluorides of elements of the group consisting of boron, germanium, aluminum, magnesium, titanium, niobium, hafnium and/or zirconium and mixtures thereof;   (b) contacting a cathode with said anodizing solution;   (c) inserting the components as anodes into said anodizing solution;   (d) applying a voltage between the anode and cathode to apply a surface coating to said components.