HEATER FOR VACUUM EVAPORATION

摘要

PURPOSE:To make the evaporation speed of a evaporating metal faster and to enhance the evaporation efficiency by coating the surface of a vacuum evaporating heater for Ni, Cr or an alloy thereof made of electroconductive ceramics with at least one or more of a carbide of Zr, Ti, or Hf. CONSTITUTION:The vacuum evaporating heater of Ni, Cr or an alloy thereof is prepared from electroconductive ceramics based on TiB2 or BN or a carbon material such as graphite or the like. Because these materials are inferior in wettability with molten Ni, Cr or an alloy thereof, said molten material is brought into a spherical shape and, thereby, a contact area is small, the evaporation speed thereof is slow. In order to improve these problems, a part of the heater which contacts with molten Ni or Cr is coated with at least one or more of ZrC, TiC or HfC by wire detonation spraying. Thereby, the wettability with said molten metal of said evaporating metal is enhanced, the evaporation speed due to the increase of the contact area is made faster and efficiency of evaporation operation is improved.