A method for preparing metal structural parts with complex shapes by 3D cold printing

Abstract

The invention discloses a method for preparing complex-shaped metal structural parts by 3D cold printing, which belongs to the technical field of cold isostatic pressing. The present invention adopts the 3D cold printing method to print out the cold isostatic wrapping green body of the glucose high polymer of complex shape, and then dips a layer of colloid thin layer on the green body surface to obtain a new type of cold isostatic wrapping; Metal powder is mixed with organic liquid to prepare a slurry and cast it in a new type of sheath until the powder completely fills the sheath, and then undergo cold pressing and vacuum sintering to prepare metal structural parts with complex shapes. In the cold isostatic pressing process, the porous and loose sheath is used to absorb the organic liquid in the slurry, so that the metal powder can be fully and evenly filled in the sheath. During the cold isostatic pressing process, the rebound is small and there is no stress concentration, which can ensure complex shapes. The compact shape of the structural part is complete without fracture, and the yield is high, which is beneficial to obtain a complete and high-strength metal structural part with a complex shape.

Description

technical field [0001] The invention belongs to the field of cold isostatic pressing, and provides a method for preparing complex-shaped metal structural parts by 3D cold printing. Background technique [0002] Cold isostatic pressing (Cold Isostatic Pressing, CIP) is an important powder metallurgy forming technology. It is a method of compressing and forming powder by transmitting isotropic pressure through a fluid medium at room temperature. It can process high-temperature alloy materials, hard alloy materials, and ceramic materials that are difficult to manufacture under conventional solidification conditions. Compared with conventional forming technology, cold isostatic pressing has the advantages of uniform product structure, no component segregation, high material utilization rate, high green density and low cost. Through CIP, the density of the workpiece can be greatly improved and the strength of the workpiece can be increased. Cold isostatic pressing is generally ...

AI Technical Summary

Problems solved by technology

However, directly filling the powder into the sheath not only requires high powder fluidity, but also increases the cost of raw materials, and is also prone to uneven and incomplete powder filling, which cannot be isostatically pressed, resulting in uneven green compact density. Even the phenomenon of green body breaking occurs, the yield rate is low, resulting in waste of raw materials and high cost, and it is difficult to prepare complex shapes and multi-symmetrical axis parts

[0004] At present, due to the limitation of the shape of the cold isostatic sheath and the filling powder, the cold isostatic pressing technology is only limited to the preparation of blocks or hollow thick-walled blanks with regular and simple shapes, and it is impossible to prepare workpieces with irregular and complex shapes.

Therefore, a method of 3D cold printing is used to prepare metal structural parts of complex shapes, using 3D cold printing technology combined with cold isostatic pressing technology, through 3D cold printing loose and porous complex shape cold isostatic pressing envelopes, and then using injection The powder-filled slurry method fills the sheath with powder, and finally obtains complex-shaped metal components after cold isostatic pressing, which is of great significance to solve the problems of difficult forming of complex shapes and low yield of pressed parts.

Images