A method for the application of which serves as a spacer ceramic particles on thin, the thermal insulation, the metal foils, which serves to

摘要

Layers of ceramic particles are thermally sprayed onto metal foils so the ceramics function as separators or distance-pieces in a stock of coated foils. The pref. methods are (a) the use of an oxy-acetylene flame at 2500 degrees C. to deposit particles 10-40 mu, esp. 30 u in size on one side of a metal foil so that about 30% of the surface is covered, (b) the use of a plasma-arc at 400-500 A with N2 or Ar as the prim. gas and H2 as the sec. gas to obtain the same particle size and distribution as in (a), esp. using Al foil coated with ZrO2 and a prim. gas : sec. gas ratio of 5 : 1. Used for the reflection of thermal radiation in vacuum where 40-80 foils are used as a flat stack or in a cylindrical form. Eliminates the use of organic binders which must be subsequently removed by heating, and produces spherical particles which do not damage the foils in the stack.