Process for producing components by powder injection molding

摘要

Process for producing a shaped metallic body from a thermoplastic composition by injection molding or extrusion to form a shaped part, removal of the binder and sintering, wherein a thermoplastic composition composed of a metal powder and a polymer mixture B1) and B2) based on a polyoxymethylene homopolymer or copolymer B1) is used as binder and to remove the binder
a) the shaped part is treated with a solvent which extracts the binder component B2) from the shaped part and in which the binder component B1) is insoluble,b) the solvent is then removed from the shaped part by drying andc) the shaped part is treated thermally at from 140 to 200° C. in an oxygen-comprising atmosphere, as a result of which the binder component B1) is removed from the shaped part;

and also a shaped metallic body which can be obtained in this way.

主权项

1. A process for producing a shaped metallic body which comprises injection molding or extruding a thermoplastic composition to form a shaped part, removal of the binder and sintering, wherein a thermoplastic composition comprising
A) from 40 to 65% by volume of at least one sinterable metal powder A, B) from 35 to 60% by volume of a binder mixture consisting of
B1) from 50 to 95% by weight of one or more polyoxymethylene homopolymers or copolymers;B2) from 5 to 50% by weight of a polymer selected from among aliphatic polyurethanes, aliphatic uncrosslinked polyepoxides, polyethers, aliphatic polyamides, polyacrylates and mixtures thereof which is homogeneously dissolved or dispersed with an average particle size of less than 1 μm in B1) and C) from 0 to 5% by volume of a dispersant, where the sum of the components A), B) and C) does not exceed 100% by volume, is used; and to remove the binder a) the shaped part is treated with a solvent which extracts the binder components B2) and optionally C) from the shaped part and in which the binder component B1) is insoluble, b) the solvent is then removed from the shaped part by drying and c) the shaped part is treated thermally at 140-200° C. in an oxygen-comprising atmosphere, as a result of which the binder component B1) is removed to an extent of at least 20% by weight from the shaped part.