Tooling for Lost-Foam Casting and related Scale-up of 3D Printing

Goal: MIT has two responsibilities under this ATP program. MIT is responsible for developing the ink-jet printhead technology which will allow for a substantial scale-up of 3D Printing - to a powderbed of 1m x .5m in printing surface. MIT is also contributing to the development of materials systems which will enable larger parts.

Approach: A modular 8-jet continuous-jet printhead has been designed. 8-jet modules can be placed one next to the other to create a printhead array of any width. A 12 module 96 jet version will be used for the ATP program. This printhead is extremely flexible in materials capability. The printhead components are designed so that they can loaded and unloaded by machine, thus allowing for totally automated set up and maintenance in the future. It is expected that this printhead can be the engine for a wide range of 3D Printing manufacturing applications where a printhead is raster scanned over the surface of powderbed.

The primary thrust on the materials work is to develop the capability to create a powder skeleton with little or no shrinkage (and not to rely on sintering to impart strength to the skeleton). An exemplar of the approach is to print a metal salt solution and to Reduce the salt to metal during a firing operation. The added metal then provides the material for the necks between powder particles and thereby forms the skeleton without shrinkage.

Sponsor: National Institute of Standards and Technology. MIT is a subcontractor to ExtrdeHone Corp and General Motors under an ATP program on Lost-Foam Tooling by 3D Printing.

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