Extruder for a system for the additive manufacture of metal parts using the composite extrusion modeling (CEM) method

Abstract

The invention relates to an extruder (7) for a system for the additive manufacture of freely formable metal parts from a composite material with or without a support structure using an extrusion method, said extruder being arranged on a three-dimensionally movable kinematic system (18) with a construction platform (11). The extruder (7) consists of a housing (2) and a worm (4) arranged in the housing (2), and the extruder (7) is provided with a mechanical drive (1) for the composite material to be extruded and a replaceable nozzle (3) which is arranged on the housing (2). The housing (2) is connected to the mechanical drive (1) via suitable means in order to transport the composite material. The housing (2) is divided into a feed section (5) with an active cooling (9), wherein the housing(2) is designed as a funnel (22), and the material of the housing (2) consists of a material with good thermal conductivity, said worm (4) having a smaller shaft diameter, a separation zone (6), in which the housing (2) consists of a material with poor thermal conductivity and thermally separates the cooled feed zone (5) from a heated plasticizing and homogenization zone (8), the plasticizing andhomogenization zone (8), in which the housing (2) consists of a material with good thermal conductivity and is provided with an active heating (10), said worm (4) having a larger shaft diameter in theplasticizing and homogenization zone than in the upper zones (5, 6), and a discharge zone (12), which consists of a replaceable nozzle (3) made of an abrasion-resistant material.

Description

technical field [0001] The invention relates to an extruder for use in a plant for the additive manufacturing of metal parts, so-called co-extrusion. However, extruders can also be used universally for plastics processing. Background technique [0002] Additively manufactured metal parts remain a costly and complex alternative to conventional manufacturing (forming, cutting, etc.). Nevertheless, it is used in larger operations in the aerospace, automotive industry and medical technology. This depends, inter alia, on the fact that additive manufacturing enables unprecedented degrees of design freedom: [0003] - complex shapes with undercuts, [0004] - up to a one-to-one reproduction of the biological structure of the human bone structure, [0005] - Lightweight components with lattice and honeycomb structures, heat-loaded, flow-conducting components (eg rocket engine components). [0006] In the field of additive manufacturing, different methods have been created over ...

AI Technical Summary

Problems solved by technology

High equipment acquisition costs and material costs, maintenance costs, dimensions of the equipment and complexity of the method are another disadvantage of the hitherto known technical solutions for additive manufacturing

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