VACUUM VESSEL AND PARTS FOR VACUUM APPARATUS

摘要

PURPOSE:To prevent brittleness phenomenon based on the deposition of gallium in a liquid-metal state by forming an inorganic protective film on both a vacuum vessel and the parts for a vacuum apparatus made of aluminum material by means of spark discharge in an electrolytic bath. CONSTITUTION:Both a vacuum vessel and the parts for the other vacuum apparatus made of aluminum material are made to an anode and a stainless plate or a nickel plate is made to a cathode and both electrodes are immersed into a chlorate aq. soln. DC voltage having an optional waveform is impressed in the optional range of 0.1-10A/cm<2> anode current density and boosted until spark discharge is generated and furthermore boosted until a required thickness is obtained and this state is maintained for a definite period. As a result, an inorganic protective film is formed on the surfaces of both the vacuum vessel and the parts for the other vacuum apparatus made of aluminum material being the anode. Further 200g/l sodium silicate aq. soln. can be used as an electrolytic bath.