The SDM Process

Shape Deposition Manufacturing (SDM) is a solid freeform fabrication (SFF) process being developed at Carnegie Mellon and Stanford University to build complex structures which could not be built with any conventional fabrication process.

Brief process overview             Detailed process description      

Brief process overview

SFF methodologies are based upon material additive processes to incrementally build-up cross-sectional layers of arbitrarily complex shapes. SFF has been widely investigated as a way to rapidly and automatically fabricate parts directly from CAD models for such applications as rapid prototyping and customized low-batch production. Current SFF processes, however, have not taken advantage of the potential benefits of incremental deposition techniques to build heterogeneous structures, i.e., multi-material, functionally-grade, embedded structures. SDM is being developed to build such heterogeneous structures made of metal, plastic and ceramic materials.

SDM integrates material additive with material removal processes, as well as other intermediate processing operations, such as embedding and stress relief, which operate on each layer. Individual layer segments are deposited as near-net shapes and then accurately machined to net-shape before depositing additional material. Each layer also consists of sacrificial support material which is removed when the entire part is completed. Several types of deposition processes are being investigated including weld-based processes, UV curables, gel-casting, and 2-part epoxy mixtures. For one example, 'micocasting' is novel process which deposits discrete droplets of super-heated metals such as stainless-steels with copper sacrificial supports.

Next-generation production tooling                

Next generation production tooling are dies for injection moling with a strong steel exterior, an internal copper core for thermal conductivity and conformal cooling channels.  A conceptual example shown below is a copper-steel structure with complex three dimensional cooling channels.

Specialized wearable computers are custom made computers that a person can wear on his/her body. The example shown below is a embedded computer which displays schematics for maintenance operations. The computer is embedded in rugged polyurethane structure, shaped to conform to the human operator.