Changes

:'''a)Powder blending from single component powders''' <br> In this common process all components including additives that are part of the powder mix are blended as single powders. The blending is usually performed in the dry stage in blenders of different design.

:b) '''b) Powder blending on the basis of doped powders'''<br> For incorporation of additive oxides in the SnO SnO2 powder the reactive spray 2process (RSV) has shown advantages. This process starts with a waterbasedsolution of the tin and other metal compounds. This solution isnebulized under high pressure and temperature in a reactor chamber.Through the rapid evaporation of the water each small droplet is convertedinto a salt crystal and from there by oxidation into a tin oxide particle in whichthe additive metals are distributed evenly as oxides. The so created dopedAgSnO AgSnO2 powder is then mechanically mixed with silver powder.c) Powder blending based on coated oxide powdersIn this process tin oxide powder is blended with lower meting additive oxidessuch as for example Ag MoO and then heat treated. The SnO particles are 2 4 2coated in this step with a thin layer of the additive oxide.d) Powder blending based on internally oxidized alloy powderse) Powder blending based on chemically precipitated compoundpowders

:'''d) Powder blending based on internally oxidized alloy powders''' <br> A combination of powder metallurgy and internal oxidation this process startswith atomized Ag alloy powder which is subsequently oxidized in pureoxygen. During this process the Sn and other metal components aretransformed to metal oxide and precipitated inside the silver matrix of eachpowder particle. :'''e) Powder blending based on chemically precipitated compound powders''' <br> A silver salt solution is added to a suspension of for example SnO SnO2 together 2with a precipitation agent. In a chemical reaction silver and silver oxide

oxide with the resulting precipitated powder being a mix of Ag and SnO SnO2.