Direct Digital Manufacturing
Direct digital manufacturing is a manufacturing process which physically constructs or repairs parts directly from 3-Dimensional (3D) Computer Aided Design (CAD) files using additive fabrication techniques, also called 3D printing or Rapid Prototyping. The 3D printed part or parts are intended to be used as the final product itself with minimal post-processing.
The process was originally known as Rapid Prototyping because the technology was used to make prototypes of parts without having to invest the time or resources to develop tooling or other traditional methods. Since the process was slow, it was used solely for prototyping.
There are presently about 25 3D printing technologies. The oldest is layered object manufacturing. The next oldest is stereo lithography. More recent technologies include selective laser sintering, inkjet technologies, fused deposition modeling and many variations. All of these technologies take a 3D model, compute cross-sections of that model, and then deposit the cross-sections sequentially on top of each other until the final geometry is achieved.
Varying the layer thickness and the fineness of the powder material both affect the model surface finish. Many methods have been devised to improve surface finishes; these usually slow down the printing process.
There are presently around 50 commercially viewable examples of 3D printing being used for tooling or intermediate parts. The main problem with adoption of the process especially on aircraft parts is the lack of qualification data developed and presented in standard handbooks. Strength, fatigue, and other design data must be developed and qualified before the processes will reach more widespread use.
The VLCOE will review new technologies for rapid direct measurement of components to derive CAD data for manufacturing.
Known areas of interest for are:
- Mylar Scanner
- 3-D laser scanners
The VLCOE will review new additive (manufacturing and repair) processes technologies.
Known areas of interest are:
- Engine blade lengthening
- Characterization of Arcam material properties
- Component manufacturing
- Corrosion repairs