Method of achieving full density binder jet printed metallic articles

Abstract

A method of producing full density binder-jet printed metallic articles. A metallic 3-D printed article is produced using a binder-jet printing method and is positioned in a hot isostatic press (HIP) container surrounded by stabilization powder. A vacuum is introduced into the inside of the HIP container. A binder used to bond powder articles together in the printed article is removed by heating the HIP container to decompose the binder and removing decomposition products by applying a vacuum to the HIP container. The HIP container is sealed with a vacuum therein and compacted under heat and pressure to remove all porosity in the printed article. The printed article thereafter is removed from the HIP container and finished to a final form.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS[0001]This application claims the priority of Provisional Patent Application No. 62 / 088,009 filed on Dec. 5, 2014 and entitled ACHIEVING FULL DENSITY BINDER JET PRINTED METALLIC ARTICLES.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to binder-jet printing and, more particularly, to the use of binder-jet printing and hot isostatic press (HIP) processing in the preparation of printed metallic articles.[0004]2. Description of the Background Art[0005]Additive manufacturing has been demonstrated to be highly effective for rapid prototyping and small lot production for plastic articles. More recently, the application of additive manufacturing to metallic materials has been growing, first in medical, dental and specialty consumer products, and now developing in aerospace applications.[0006]The benefits of direct metal additive manufacturing are best realized in applications involving: high material loss...

AI Technical Summary

Benefits of technology

[0013]Combining binder-jet printed and cured article(s) with near net shape hot isostatic press (HIP) processing solves both problems encountered with fusion melt processes as well as the baseline binderjet process of high temperature sintering. In this improved process, a binder-jet printed and cured article is packed in a HIP container with shape stabilizing powder media. This media can be non deforming such as Zircon sand or deforming media such as steel or glass powder depending on the desired compaction dynamics. All thermal operations are conducted at temperatures below which detrimental microstructural modification will occur. Typically this is below the beta transus for titanium and titanium alloys, which is significantly b

Problems solved by technology

Undesirable Microstructural Modification

Some specialty alloys such as titanium or superalloys experience undesirable microstructural changes when processed using e-beam or laser direct melt fusion or the high temperature sintering near the melt temperature used to densify binder-jet printed articles.

The above methods have restrictions on powder size that significantly impact cost.

Since spherical powder is the most desirable for these processes and spherical powder cost is greatest for fine particle sizes, the need for fine powder size in

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