LUBRICANTS Lubricants reduce the internal friction of the extrusion body and the friction between the body and the extruder screw and die.
Lubricants reduce the internal friction of the extrusion body and the friction between the body and the extruder screw and die.
Using water as a suspension medium, instead of organic solvents, for the preparation of hard metal powders has ecologic advantages and, as a general rule, helps to cut costs. The application of an oxidation inhibitor is recommended to reduce oxygen absorption of hard metal.
The addition of wetting agents promotes reduction of surface tension of the preparation water. The use of wetting agents further makes it possible to incorporate compounds that are normally difficult to wet more readily. Last but not least, wetting agents perfectly facilitate the crushing of all components used during wet grinding.
Plasticisers, acting as swelling agents, increase the plasticity of a body. These additives absorb a portion of the available preparation water and increase the workability of the body, thanks to their swelling ability. This makes it possible to manufacture extrusion bodies based on non-plastic powder metallurgical raw materials. On account of extrusion body surfaces being dull in many cases, it is recommended to combine plasticisers with pressing agents and lubricants.
