NIST Additive Manufacturing
What is additive manufacturing?
Additive manufacturing fabricates parts by building them up layer-by-layer (as opposed to cutting material away or molding it.) It shows great promise for applications as diverse as lightweight aerospace structures and custom biomedical implants. 3-D Printing is one of several approaches to additive manufacturing.
NIST’s John Slotwinski working with a metallic object whose
shape is designed to test the capability of an additive manufacturing
Credit: Beamie Young\NIST
A laser melts metal powder, which then cools to a solid. The
laser only melts in areas that correspond to a particular layer
in the computer design.
Credit: Beamie Young\NIST
How does it work?
Metallic, plastic or ceramic materials are laid down one thin layer at a time and placed precisely as directed by a digital design file. The raw materials are often in the form of powders or wires that can be melted and shaped by a laser.
An example application for the medical industry would be an artificial jawbone. A 3-D computer model of a jawbone is created based on the patient’s bone structure, and this model is sliced into many layers. The computer then feeds the information into the additive machine, which could generate the complex bone structure substitute out of metal.
Which industries use it and how?
Additive manufacturing shows promise for the defense, energy, aerospace, medical and commercial sectors. Its alternative approach to machining, forging, molding and casting makes it a good choice for rapidly making highly customized parts. The technology also shows promise for creating parts on site, such as at forward-stationed military bases. Because of its potential, many companies are using the technology to get themselves into a position to use it. The growing field of companies using the technology includes makers of machine parts and novelty items.
What impact could it have on the economy/exports/jobs?
One expected long-term impact is in highly customized manufacturing, where the technique can be more cost-effective than traditional methods. Instead of the difficulty of customizing a mold, for example, a manufacturer could just start with a powder and build a component directly. If you can imagine it, you can make it.
What is NIST doing to accelerate use and innovation with additive manufacturing?
From performing its own in-house additive manufacturing research to funding projects elsewhere, NIST is advancing additive manufacturing in a number of ways.
In NIST’s Engineering Laboratory, the Measurement Science for Additive Manufacturing Program has four projects in metal-based additive manufacturing:
- Real-Time Control of Additive Manufacturing Processes involves improving the quality of the finished manufactured parts. At this point, high-quality parts can be made, but ensuring consistency is difficult. This project will develop process metrology, in-process sensing methods and real-time process control approaches to maximize part quality and minimize variability.
- Qualification for Additive Manufacturing Materials, Processes and Parts aims to improve the process for ensuring the quality of manufactured pieces of critical importance, such as a turbine blade in an aircraft engine or medical parts for implantation in the body. The quality assurance process is currently rather long and expensive, so this project will develop methods and protocols that will reduce the time and cost.
- Systems Integration for Additive Manufacturing aims to coordinate the various parts of the additive manufacturing process, such as the software used for design and the machine control software that creates the finished part. This project will establish an “architecture” for how these parts of the process fit together effectively, including metrics and validation methods to shorten the design-to-product cycle time.
- Characterization of Additive Manufacturing Materials involves developing measurements and standards for characterizing powdered metals—raw materials for additive manufacturing—in terms of particle size and shape, chemical consistency and size consistency. NIST is concentrating on metal powders right now and helping develop methods so that industry can rigorously verify that two nominally identical powders are in fact identical. This will lead to parts with better and more consistent properties. NIST's aim is to develop characterization test methods for the raw powder materials used, as well as the final products fabricated by the process.
Built like a real dog nose, the detector reaches out and
“grabs” vapor from ahead of itself – the reason why a dog is
such an amazing chemical detector.
NIST also has awarded two large grants to fund research projects aimed at improving measurement and standards for additive manufacturing: $5 million to the National Additive Manufacturing Innovation Institute in Youngstown, Ohio, for a collaborative research effort involving 27 companies, universities and national laboratories, and $2.4 million to Northern Illinois University to develop tools for process control and qualifying parts made with additive manufacturing processes. NIST has also made several smaller cooperative agreements with various groups. These competitively awarded grants will support industry’s high priority objective of ensuring that quality parts are produced and certified for use in products made by a variety of industries and their supply chains. For more information, visit http://manufacturing.gov/msam_awards.html.
Research Highlight: The artificial dog nose
Researchers from NIST and Penn State have developed the first anatomically correct dog nose that realistically sniffs. The artificial dog nose, created on a 3D printer, enables real-time flow visualization studies of how dogs employ aerodynamics to sample smells.
To sniff, the nose expels two turbulent airjets, which suck fresh odor-laden air from several centimeters ahead towards the nose. The new vapor sample is immediately inhaled and “analyzed.” This process repeats five times per second. Lessons learned from this active aerodynamic sampling system are being integrated into next-generation vapor sampling devices.