In 2017, materials for 3D printing and additive manufacturing (AM) will be getting better and more closely fine-tuned for higher-quality and larger end-production parts. At the same time, the types of materials available for 3D printing processes continue to widen, at the low, medium, and high ends. The expansion of engineering-grade materials is being helped along by multiple sources. These include standards bodies, government labs, consortia, and other groups, as well as more large materials companies like Solvay entering the fray. Another major source will be companies leveraging off of HP's Multi Jet Fusion ecosystem open materials market headed by products from Evonik and BASF.
Standards and Guidelines for Improving AM Materials
Making high-quality end-production parts with AM and 3D printing methods requires some carefully defined standards and guidelines for materials and printed parts, as well as machines and processes. This is especially true for metal parts, which continue to be the fastest-growing segment of commercial 3D printing, according to a recent study by IdTechEx. Several different types of organizations are getting into the act, beyond the well-known standards bodies, and these efforts will increase in 2017.
Alcoa's 3D printing metal powder production facility is located at its Technology Center, the world's largest light metals research center, now part of Arconic. There it's developing proprietary titanium, nickel, and aluminum powders optimized for 3D printing aerospace parts. (Source: Arconic)
In 2016, the creators of the free, searchable Senvol Database began issuing a new set of industrial AM and 3D printing tools for engineers wanting to use additive technology for end-production. The Senvol Indexes are datasets for AM material characterization, and the only source of commercially available data of this kind. The Indexes, like the Database, were developed without involvement from machine OEMs or material suppliers, to reduce the barriers of entry for companies interested in additive for end-production.
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For example, an Index detailing Arcam (AP&C) Ti6Al4V (45 - 106 microns) powder processed on the Arcam Q20 machine includes data such as material properties, process parameters, powder characteristics, and hot isostatic pressing (HIP) effects, gathered according to aerospace best practices. The Indexes were created to replace the duplicative efforts of aerospace companies doing their own material characterization. Since different industries use very similar materials -- for example, Ti6Al4V is also used in medical implants -- the dataset can be shared between aerospace and medical, and any other industry where engineers want to use this material on that specific printer.
Senvol president Annie Wang has been selected as vice chair of the Data Management Committee for the SAE AMS-AM Additive Manufacturing Committee, a technical committee in SAE's Aerospace Materials Systems Group. Her focus will be establishing a system to ensure that material specifications are controlled and traceable to statistically substantiated data that's been analyzed by documented procedures. The Data Management Committee will also coordinate with the SAE's MMPDS Emerging Technology Working Group for new metallic materials and CMH-17 for new polymer composite materials.
Metals, Metals, and More Metals
As we've heard many times from pundits and engineers alike, metals technologies, plus the shift to end-production parts, are the future of industrial and commercial 3D printing and AM. The recent IdTechEx report says metals printer sales are growing at 48% and material sales are growing at 32%, in a wide variety of industries.
The report covers selective laser melting (SLM), electron beam melting (EBM), blown powder, metal + binder, welding, and some emerging technologies, using a wide range of alloys: aluminum, cobalt alloys, nickel alloys, steels, nitinol, titanium alloys, gold, platinum, palladium, silver, copper, bronze, and tungsten. Because of the heavy emphasis on aerospace and medical applications, which have led metals AM, the titanium alloys used by both have a 31% market share by volume. The aerospace industry is also heavily investing in cobalt, nickel, and aluminum alloys.
A more targeted study by Absolute Reports, looking only at SLM and EBM, predicts a growth rate of 26.86% by 2021, and reports that in Europe metals AM tech grew by 54.92% from 2011 to 2016.
One of the biggest influences on powder metals is now the rise of AM, as we reported recently. Most leading metal powder makers are developing powders for additive, although there are only about 15 commercially available, and most installations producing parts with metals AM are doing short runs of 100 units or less.
Since metal powders used for 3D printing durable, high-quality aerospace parts are available in only limited quantities, aluminum leader Alcoa opened a new plant specifically to produce 3D printing metal powders at its Pittsburgh, Penn. Alcoa Technical Center. There it's developing proprietary titanium, nickel, and aluminum powders optimized for 3D printing aerospace parts. The facility is now part of Arconic after the recent separation from Alcoa's traditional commodity business.
Much recent activity has also been aimed at producing better metal powders. The main problem is that many metal alloys produced into powders for use in AM were not designed for that environment, but for casting. So many materials makers are redesigning them from the ground up for 3D printing. NanoSteel, for example, is designing metal powders specifically for the fast-cooling environment of AM, not just translating them from powders originally designed for casting.
The availability of new metal powders developed specifically for 3D printing will continue and expand in 2017. Also expect continual work to understand and verify the microstructures of 3D printed parts, especially metal ones.
For example, at Carnegie Mellon University's leading NextManufacturing Center for AM, researchers have used synchrotron-based x-ray microtomography to make detailed images of 3D-printed titanium parts, to help characterize materials and improve the parts' internal structure.
Previous research found that most tensile properties of 3D-printed titanium components made with Ti-6Al-4V alloy on an EBM machine met or exceeded conventional manufacturing standards. But because of excessive porosity, the fatigue properties of parts were consistently inferior. The team found that most of this porosity can be eliminated by adjusting the printer's process parameters, but methods must include enough information to properly characterize it. The center's method, which does, gave a minimum feature resolution of 1.5 microns.
Researchers at Lawrence Livermore National Laboratory discovered interactions that can lead to porosity in parts produced by laser powder bed fusion metal processes, contributing to future better part performance. (Source: Julie Russell/Lawrence Livermore National Laboratory)
Researchers at Lawrence Livermore National Laboratory also looked at porosity issues. They discovered what interactions can lead to porosity in parts produced by laser powder bed fusion metal processes. Due to evaporation that occurs when the laser irradiates the metal powder during a build, vapor flux clears away powder near the laser's path. This reduces how much powder is available when the laser makes its next pass, and that causes gaps and defects in the finished part.
The team used a vacuum chamber, an ultra high-speed camera, and a custom-built microscope setup to observe ejection of metal powder away from the laser during the melting process. Through computer simulation and fluid dynamics, the researchers also built models to help explain the particle movement. The effect has important implications for part quality and build speed, so it must be captured and used to update simulation models, which will help optimize the process. Next steps will be investigating how porosity develops in real time and exploring advanced diagnostics and modifications to the process for improving build quality, using the new information.
But Metals aren't the Only Materials that Count
Metals, of course, aren't the only materials that count in 3D printing. Photopolymers still represent the biggest part of AM materials at 59.8% in 2015, according to a recent report from BCC Research. But it's also the slowest growing segment, and expected to decline to 47% by 2021. During that time, the report predicts that thermoplastics will remain the second-largest group at 25% to 26% of the market. Ceramic, metals, and other materials comprise the remaining categories.
One of the latest entries into engineering-grade polymers for 3D printing is Evonik's recently announced VESTOSINT 3D Z2773. This material is its first new plastic powder developed with HP for use with HP's Multi Jet Fusion 3D printers, and the first certified material in HP's Open Platform program, announced last May, which will support this line of printers.
The new PA-12 powder has superior mechanical properties and is FDA (Food and Drug Administration) compliant, so components printed with it can be approved by the FDA for food contact. For several years, Evonik has produced plastics for the industrial production of high-performance components using 3D printing technologies. These include other PA 12-based VESTOSINT powders with high quality and processing capabilities, and with properties profiles for each powder matched to a specific 3D printing technology.
BASF, an HP materials partner in the same program, also said recently it's beginning development of 3D printing materials with HP, leveraging its broad portfolio of engineering thermoplastics, polyurethanes, photopolymers, and other polymers, as well as metal systems. HP's other Open Platform materials partners include Arkema and Lehman & Voss.
A 3D-printed fuel intake runner fabricated from Solvay's KetaSpire PEEK instead of the typical aluminum uses 10% glass fill. (Source: Solvay)
Although polymer leader Solvay makes existing 3D printing materials, the company recently announced it will expand those capabilities as part of its advanced lightweighting solutions that aim at replacing metals. Building on its established AM technical center and production facility for Sinterline Technyl in Lyon, France, Solvay has opened a new laboratory at its Research & Innovation Center in Alpharetta, Georgia for advanced AM materials.
The company has contributed its materials expertise to a 3D printed part for the Polimotor 2 all-plastic engine, designed by industry pioneer Matti Holtzberg. The project aims to leverage advanced polymer technology for a four-cylinder, double-overhead CAM engine weighing 40kg less than today's standard production engine. The plenum chamber is 3D printed with selective laser sintering (SLS) using Solvay's Sinterline Technyl PA 6 powder grade reinforced with a 40% loading of glass beads.
Solvay has also conducted tests comparing the tensile properties of samples 3D printed and injection molded from KetaSpire KT-820 PEEK. In a 3D-printed fuel intake runner fabricated with this material, the KT-820 custom-formulated grade is reinforced with 10% glass fill, and was produced with Arevo Labs' Reinforced Filament Fusion technology. Other plastics products the company is developing for AM include its AvaSpire PAEK, KetaSpire PEEK, and Radel polyphenylsulfone (PPSU) for Fused Filament Fabrication (FFF) processes, along with PEKK for SLS.
Ann R. Thryft has been writing about manufacturing- and electronics-related technologies for 29 years, covering manufacturing materials & processes, alternative energy, and robotics. In the past, she's also written about machine vision and all kinds of communications.