in the manufacture of giessbrei sinternden formkoerpern from metal powders

摘要

Sintered tungsten or molybdenum products are formed from a slip casting composition with a pH valve of 3 to 9 and comprising the metal powder, a liquid carrier, a viscosity controlling agent, an anti-foaming agent and a melting agent. A molybdenum slip composition is formed from a mixture of molybdenum powder at least 90% being less than 10 micron, a liquid carrier such as water or polyvinyl alcohol in a proportion of 1,25 to 1,5 parts per part of powder, an anti-foaming agent such as the silicones, octyl alcohol or amyl alcohol, 0,01 to 0,5 gms. per 100 ccs. of molybdenum of a melting agent such as dioctyl sodium sulphosuccinate and a viscosity controlling agent such as polyvinyl alcohol, sodium or ammonium alginate and methyl cellulose. The slip with a pH of 6 to 7 is cast into an absorbent mould and the green casting is sintered at 1900 DEG C. in hydrogen.