Pioneers in Additive Manufacturing: Session II
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Powder Materials Committee
Program Organizers: James Foley, Los Alamos National Laboratory; Paul Prichard, Kennametal Inc; Iver Anderson, Iowa State University/Ames Laboratory; David Bourell, University of Texas
Tuesday 2:00 PM
February 28, 2017
Location: San Diego Convention Ctr
Session Chair: Paul Prichard, Kennametal Inc.
2:00 PM Invited
Pioneering International Consensus: Brent Stucker1; 13DSIM
For the first 20 years of Additive Manufacturing (AM), there were no AM industry-specific international standards. This led to significant confusion in both academia and industry. In 2008, a group of international leaders in academia, government and industry gathered to rectify this problem and form ASTM F42. Soon thereafter, ISO TC261 was formed and began collaborating with ASTM F42 to develop and propagate international standards for AM. Due in part to this international consensus, research productivity and industrial adoption of AM has flourished.
2:30 PM Invited
Making Things Bit-by-byte: Opportunity in a Fortuitous Convergence of Technologies: Khershed Cooper1; Ralph Wachter1; 1National Science Foundation
Traditionally, part manufacturing has been by shaping and molding materials using fixturing and tooling. In the 1980s, incorporating information technologies into manufacturing technology, a specialized research area emerged that defined a part as an enormous collection of carefully arranged microscopic bits of material that were incrementally fused together. Its simplicity offered a new paradigm for part manufacturing with the benefit of mass customization at a near constant unit cost. Called additive manufacturing, the field grew, patents were filed, international standards were proposed, and startups were spun-out. With impressive improvements in computing and sensing, new growth in the field fostered the "maker" movement. Its next chapters involve the intertwining of cyber-physical systems, advanced materials, and even biological processes. In this talk we will present a retrospective of government investments in additive manufacturing R&D and discuss a future for cyber-enabled additive manufacturing that is responsive to concerns of certification, safety, and security.
3:00 PM Invited
Early Developments of AM within the UK: Phill Dickens1; 1University of Nottingham
This presentation will cover the range and type of work that was undertaken in the UK on Additive Manufacturing. It will highlight the work by key researchers and discuss how the technology was developed and exploited. A comparison will be made with current work on Additive Manufacturing.
3:30 PM Break
3:50 PM Invited
Laser Engineered Net Shaping - AM Metal Parts with Exceptional Material Properties: John Smugeresky1; David Keicher2; 1Additive Manufacturing Materials Consultants; 2Sandia National Laboratories
The Laser Engineered Net Shaping (LENS) process was developed with a focus on 3D printing metallic components without degradation to material composition and with materials properties comparable or better than similar composition wrought metals. Experimental results have shown that this objective has been met for a variety of material systems. Results will be presented for 304 stainless steel, Ti-6V-4Al and Inconel 625. Historical data demonstrates that compositional variation between the starting powder stock and LENS fabricated components is minimal. Numerous experiments have shown increase in both strength and ductility in LENS fabricated parts as compared to wrought counterparts. Data will be presented to support that these properties are achieved due to the high cooling rate associated with the LENS process and the strengthening mechanism will be discussed and supported with experimental data. Sandia National Laboratories is funded by the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
4:20 PM Invited
AFRL Contributions to Additive Manufacturing of Titanium, ca 2000: Pamela Kobryn1; Lee Semiatin1; 1US Air Force Research Laboratory
From 1998-2003, the Air Force Research Laboratory performed extensive R&D on powder deposition of Ti-6Al-4V using both low-power (LENS™) and high-power (LAM™) systems. Major areas of research focused on the effect of process variables on microstructure evolution and properties and the application of such AM techniques to fabricate preforms for forging. In the former area, the effects of laser power, scan rate, and substrate texture on the microstructure and texture of the build were established. Microstructure observations were interpreted within the context of a solidification (G-vs-R) map previously developed at AFRL for macro-solidification processes. Mechanical properties were found to be comparable to those of castings; noticeable improvements were obtained when post-deposition HIP was used. In the forging area, it was shown that the breakdown of the transformed microstructure in AM preforms of Ti-6Al-4V followed trends similar to those for conventional ingot-metallurgy products.
4:50 PM Invited
Process Fundamentals for Selective Laser Melting: Power Ratio, Melting, Porosity, and Build Properties: Ralph Napolitano1; 1Iowa State University
The selective laser powder melting process for additive manufacturing relies on sufficient melt superheat to facilitate complete powder melting and sound fusion. Process parameter ranges for sound builds can be established using energy input criteria, and a power ratio parameter is investigated here, establishing a threshold for the onset of gross porosity and degraded mechanical properties. The criterion is demonstrated for 316L stainless steel, and extension to other build materials is discussed.