MNA talks to three experts from GE, to get an inside look at what is on the agenda for advanced manufacturing and highly innovative materials development

To gain further understanding of the world of materials development and the vast amounts of innovation and research underway in that area, where better to start than the corporate giant GE? At GE Global Research, the team works on early TRL, disruptive technologies for its core GE businesses (Aviation, Power, Renewable Energy), government agencies and its strategic partners.

As Timothy Hanlon, Principal Engineer of the Metals & Ceramics Department, at the GE Global Research Center (GRC), highlighted, developing advanced manufacturing techniques/materials is a core competency at GE Global Research. “The drive at our business units to continuously improve efficiencies in our gas turbines, for instance, requires that GE remain at the forefront of these technologies,” he explained. “Additive manufacturing has enabled complex part geometries that were previously out of reach using traditional manufacturing practices, with modalities such as Direct Metal Laser Melting (DMLM), Electron Beam Melting (EBM), and Binder Jet paving the way. Couple that with GE’s rich history in alloy development, and the potential for step changes in performance becomes enormous. Additionally, the pace of manufacturing and materials development at GE has been dramatically improved over the past decade through the use of advanced materials modelling tools and the application of artificial intelligence to the design process.”

Indeed, researchers at the GRC have been working for decades on various forms of advanced manufacturing, from laser-based, powder consolidation systems, to methods of manufacture that leverage high-velocity 15powder deposition. “In parallel to these research endeavors, GRC scientists have an equally impressive history with materials development that complement these advances in manufacturing,” commented Joseph Vinciquerra, Senior Principal Engineer and Technology Platform Leader for Additive Manufacturing at the GRC.

“Over the past five years, there has been an astonishing proliferation of additive manufacturing, or industrial 3D-printing, on the global scale, and GE have been at the forefront. At GE Global Research, our teams are working around the clock on new additive machine technology, new software and controls strategies for industrial 3D-printing, and of course, new additive materials. Specifically, we’ve taken our decades of know-how and experience in the design of high-temperature alloys and applied that expertise to the development of new materials systems designed specifically for our additive manufacturing modalities of interest, such as DMLM, EBM, and Binder Jet.”

Beyond the traditional
It is clear that GE’s research extends across multiple applications – Kristen Brosnan, Technical Operations Leader, Metals & Ceramics, at the GRC, gave some more specific details about GE’s work for the investment casting industry. “We are making significant advancements towards digital tool sets. We have developed what is known as the ‘Digital Foundry’ to support our investment casting initiative for Industrial Gas Turbines (IGT) hot gas path components. The Digital Foundry is a collection of models and know-how used to predict wax pattern shrink, thermal, mechanical, microstructure and dimensional responses to process and materials property input data. It captures the entire investment casting process for nickel super alloys – the highest temperature and creep resistant alloys used in a hot gas path for turbines. It is able to predict the thermals, stresses, and solidification behavior during the actual casting process, which allows us to anticipate and create designs and geometries that minimize distortio , stray grains, and freckles and other critical indications prior to pouring metal. Combining the Digital Foundry with additive core and pattern processing is allowing us to forge the path toward achieving CAD to casting outcomes in half the typical development cycle.”

“The cycle time for material and process development can be dramatically reduced,” agreed Timothy, “and improved margins in materials behavior often opens process windows substantially, increasing yield and saving cost. For example, improving the weldability of a high temperature superalloy for use in a DMLM application often leads to more flexible build parameter sets, enabling higher speed/more cost-effective printing.”

Added Joseph: “The materials we’re developing for additive manufacturing are unique in that we’re looking beyond simply converting traditional engineering alloys to additive manufacturing (though, we’re doing that too) but, instead, tailoring alloy chemistries to be fully optimized for these new manufacturing methods.”

New applications
The technology that Kristen referenced applies to IGTs and aviation turbines, but she can see how it may impact other segments as well, and Joseph explains this is one of its major benefits: “One of the most exciting aspects of our work in additive manufacturing is working with our partners in GE Additive (GE’s additive manufacturing commercial business unit) to explore markets outside of our traditional applications of interest,” he said. “While most of our work has historically revolved around applications in the aerospace and power generation sectors, we are now additionally turning our attention to applications in the automotive markets, as an example.”

Alongside expanding the applications of these new solutions, GE is also working on converging materials development with other state-of-the-art technologies, such as artificial intelligence (AI) and machine learning (ML). “We are looking at this from a couple of perspectives – going faster to expand our materials catalog and to advance autonomous research and manufacturing,” Kristen noted. “One example is our work on Cold Spray. In fact, my colleague Leo Ajdelsztajn discussed recent advances at GE in this particular additive modality at the 2018 MRS Fall Meeting, 25-30 November, in Boston. In Cold Spray, robots spray in 3D with 12 degrees of freedom. The applications are wide ranging – for example, the repair or development of manufacturing techniques for large aviation parts. Using in-situ 3D scanning and machine learning to modify the robot tool paths in-situ, the manufacturing of large complex parts can be achieved faster.

“GE is definitely not alone in looking at machine learning 16and AI to advance materials development. At the 2018 MRS Fall Meeting (where I served as one of the meeting chairs) we had a full five-day symposium (including a tutorial!) on Machine Learning and Data-Driven Materials Development and Design, with devoted sessions in areas like machine learning for data-driven design, autonomous research, deep learning and neural networks for materials, to name a few. In addition, Sergei Kalinin of Oak Ridge National Laboratory (ONRL) gave a Symposium X talk at the 2018 MRS Fall Meeting on ‘The Lab on a Beam: Big Data and Artificial Intelligence in Scanning Transmission Electron Microscopy’.

“Some Materials Science degree programs have also embraced this growing area – for example, the National Science Foundation (NSF) has funded traineeships like the Data-Enabled Science and Engineering of Atomic Structure (SEAS) at North Carolina State University to recruit and train researchers in new ways of applying these advanced statistical tools to physical data.”

Exponential technologies
“Right now, at GRC, AI and various forms of ML are being heavily utilized across a number of different projects related to materials development and optimization, and incorporation of AI and ML in the development of materials, as well as the optimization of these materials for advanced manufacturing modalities, like additive, is the ‘next big thing’,” continued Joseph. “In our work related to additive manufacturing, for example, we are using a specific type of machine learning to dramatically reduce the number of experiments required during the early phases of alloy design for additive. In another example, we’re using a combination of computer vision and machine learning to potentially reduce the costs associated with post-build inspection from additive manufacturing. There are applications where we are also leveraging deep learning algorithms to help quickly return cause-and-effect relationships between physical observations of structures and the behavior of the material that structure is made of.”

“We might need multiple symposia in future MRS Meetings to capture this growing area!” Kristen added. “Incorporating AI into materials design and manufacturing will definitely expand, and I think we will continue to go more interdisciplinary in a big way. For example, biomaterial interfaces, bioelectronics, energy storage, thermal management…as we trend toward higher temperatures, more extreme environments, and to higher efficiency systems we need more advanced materials solutions. And we need to get there faster. That’s where additive and AI become important.”

Furthermore, as Timothy pointed out, the convergence of 17AI, ML, advanced manufacturing, advanced characterization/testing, and traditional metallurgy will enable the next breakthrough in materials development. “Not only in terms of material capability, but also as an enabler for location-specific properties,” he said. “Imagine being able to tailor the properties of a material from location to location, within a single part. That creates incredible design flexibility, and huge performance potential.”

The intersection between AI/ML, materials development and optimization, and additive manufacturing is described by Joseph as ‘an incredibly exciting place to be focused right now’. “With that being said, there continue to be incredible advances made in our understanding of the metallurgy and materials behavior from advanced manufacturing methods like additive,” he concluded. “When we talk about exponential technologies, like additive, it’s fun to try and envision where the state of the science will be ten years from now—and undoubtedly, despite all that we know today, we will almost certainly surprise ourselves once we get there!”

Kristen Brosnan, Technical Operations Leader, Metals & Ceramics, General Electric Global Research.
I currently lead a team of ceramists and metallurgists in our Structural Materials Division. We deliver key high temperature materials technology for industrial gas turbines, including critical new alloys, Ceramic Matrix Composites (CMCs), coatings for the LEAP and GE9X Aviation engines, repair technologies for legacy engines, and new investment casting technology for the GE Power HA gas turbine.
www.geglobalresearch.com

Joseph Vinciquerra, Senior Principal Engineer and Technology Platform Leader for Additive Manufacturing at the GE Global Research Center (GRC).
I currently lead GRC’s efforts in materials-related research for Additive Manufacturing. Together with a multidisciplinary team, I am focused on architecting new technologies aimed at accelerating the development and optimization of additive materials through the convergence of digital and physical sciences.
www.geglobalresearch.com

Timothy Hanlon, Principal Engineer, Metals & Ceramics Department, GE Global Research Center (GRC).
I am a metallurgist supporting the GE business units in the area of structural alloy development, with particular emphasis on building and optimizing processing/structure/property relationships. As an alloy developer, my experience at GE has ranged from producing traditional powder metallurgy and cast/wrought alloy systems, to new material discovery in additive manufacturing modalities.
www.geglobalresearch.com