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Title
Verfahren zur Herstellung von Bauteilen aus Pulvern
Date Issued
2000
Author(s)
Veltl, G.
Patent No
1997-19737866
Abstract
NOVELTY - A component is produced from a powder which is mixed with a quantity of thermoplastic binder or binder mixture such that the green body weight does not exceed the flow limit during heat-up for sintering. The green body is produced by pressing the powder mixture at above the binder softening temperature to cause viscous flow even in regions transverse to the pressing direction. DETAILED DESCRIPTION - A component is produced by (a) mixing powder with a thermoplastic binder or binder mixture in a quantity (preferably 0.5-4 wt.%) such that the green body weight does not exceed the flow limit during heating up for sintering; (b) introducing the preferably preheated powder mixture into a heated tool; (c) heating to above the binder softening temperature; (d) pressing the powder mixture from at least one side using a punch to cause viscous flow even in regions transverse to the pressing direction, preferably to produce a green body of greater than 70% theoretical density; and (e) si ntering the green body. USE - For producing components from a ceramic, glass, plastic or metal powder by a hot flow compacting technique, followed by sintering. ADVANTAGE - The process prevents formation of cross-flow cracks ('dead-water cracks'), allows low cost production of components having a more complicated shape than is possible with conventional axial pressing methods and produces a pressed part which exhibits lower shrinkage than powder injection moulded parts.
Language
de
Patenprio
DE 1997-19737866 A: 19970829