The EMIT lab (Engineering MaterIals for Transformative technologies) at CMU run by Sneha Narra focuses on advancing metal additive manufacturing knowledge to manufacture light-weight organic designs and utilize novel, advanced materials. At a scientific level, our group studies the fundamentals of additive manufacturing processes, investigates the resulting material microstructure and properties, and develops process design paradigms. Our group’s mission is to lower the carbon footprint, primarily in aerospace, automobile, and energy industries. This will be achieved either through reduced material and/or operational usage or through enabling transformative technologies, such as nuclear fusion and high-efficiency turbine systems.
Sneha Narra’s academic training and experience has led to the establishment of the EMIT lab, working at the intersection of mechanical and materials science and engineering and leveraging data-driven methods to expand advanced manufacturing capabilities.
As an instructor, Narra’s goal is to help her students learn effectively in a comfortable environment and spark interest in them to explore outside the classroom. To meet this goal, she adopts a teaching philosophy that builds on creating an inclusive learning environment, active participation from students, learning through real-world examples and demonstrations, and assessment techniques optimized for long-term retention and exploration. Outside the classroom, Narra is passionate about mentoring women in engineering. Specifically, she participates in outreach activities, educates students about professional development opportunities, and provides opportunities to conduct research in interdisciplinary topics.
President Biden Visit
On January 28th, our group participated in the Mill-19 facility tour and demonstrated the wire arc additive manufacturing process in our lab in collaboration with Lincoln Electric Additive Solutions. We discussed the benefits of metal additive manufacturing with the President of the United States. We are fortunate to be part of the additive manufacturing community and honored to represent our field during the President of the United States’ visit to CMU.
(Left - Right) William Templeton, Sneha Narra, President Biden. See President Biden's tweet about the visit.
Labs and facilities
NextManufacturing Center houses various fusion-based metal additive manufacturing equipment that our lab uses in our research work.
We utilize electron microscopy and x-ray facilities at the Materials Characterization Facility (MCF), to conduct material characterization work.
We have robotic wire arc additive manufacturing (WAAM) equipment in our lab at Mill 19. In the following video, Lincoln Electric’s WAAM machine deposits weld beads in a layer-by-layer manner to build 3D structures. WAAM allows engineers to produce large 3D structures relatively fast compared to alternate additive manufacturing processes and traditional manufacturing processes. Builds on the scale in the video, around 1ft x 1ft x 0.5 ft footprint, take around 15-20 hours when using a qualified process. In the video below, three build layers are shown at an increased speed.
Critical defect size prediction
A major factor determining the fatigue life of fracture-critical parts is the effect of process-induced defects and the critical pore/defect size. Existing part qualification procedures rely heavily on time-consuming experimentation and testing procedures to determine the fatigue life. To address this gap, we are developing approaches that integrate processing and statistical modeling to systematically define data requirements and ultimately predict critical defect size in complex parts with heterogenous defect distributions.
Spatial and temporal effects on microstructure
We are collaborating with the computational modeling experts at University of Pittsburgh to develop computational process design approach that significantly reduces the need for experimentation. Toward this goal, we are developing an experimentally validated process simulation tool to predict defect regime and phase transformations in the laser powder bed fusion process. Our group at CMU is designing the experiments and conducting material characterization to understand the effects of heating/cooling and thermal fluctuations at different time scales.
AI-enabled smart drying
Heating processes account for 61% of annual manufacturing end-use energy consumption, of which the drying industry is the second-largest consumer. This project is an interdisciplinary collaborative effort integrating novel drying approaches, advanced sensing technologies, and machine learning to minimize the energy consumption in the drying process while maintaining product quality. Our group is developing physics-informed neural networks to replace time-consuming numerical modeling, handle noisy data, and integrate process conditions with sparse sensor measurements.
Microstructure evolution in wire arc AM
The high energy input in wire arc additive manufacturing leads to in-situ heating of the previously deposited layers, which in turn, can have a notable effect on the as-fabricated microstructure of age hardenable materials. Hence, a comprehensive understanding of in-situ thermal cycles and heat accumulation on the microstructure evolution and resulting properties can be a key to optimal process design. We utilize a suite of characterization and testing techniques (SEM, EBSD, XRD, hardness, and tensile testing) and in-situ monitoring data (thermocouple and IR camera), and conduction-based heat transfer models (numerical) to investigate the feasibility to tailor microstructure in age hardenable steels subjected to non-equilibrium solidification conditions and thermal gyrations.
William Frieden Templeton
Graduate students currently advised at WPI
- Hanshen Yu, Ph.D. student, June 2020-present, co-advised with Professor Jamal Yagoobi
If you are interested in joining the EMIT Lab at CMU, please read the appropriate section below.
Undergraduates: Projects are advertised through the MechE newsletter as they are available. Please refer to this information for opportunities to join the lab or email Dr. Narra with the tag [Undergrad] in the subject if you are interested in whether new projects may be becoming available.
Graduate students: All graduate students (MS or Ph.D.) will only be considered through the official CMU application system. Please apply online. If you are an admitted MS student and would like to learn about available projects please refer to the MS Canvas page or email Dr. Narra with the tag [MS] in the subject.
Postdocs: No postdoc positions are available at this time.
We look forward to hearing from you!
Biden calls for investment in American innovation
President Biden touted the importance of advanced manufacturing innovation, robotics, 3D printing, and artificial intelligence during his recent visit to Mill 19.
Metal 3D printing across scales
New faculty member Sneha Prabha Narra is interested in utilizing recent advances in in-situ monitoring, process modeling, and fundamentals of welding to advance the use of wire arc additive manufacturing for new applications and materials.
- Yao Xu, Ph.D. student, Aug 2018 – May 2022, co-advised with Professor Brajendra Mishra, currently working for Mattson Technology
- Mahya Shahabi, Aug 2019 – May 2021, currently a Ph.D. student at WPI
- Prajwal Bharadwaj, January 2021 – May 2021, currently a Ph.D. student at WPI
- Krishnan Giridharan, October 2019 – May 2021, currently an associate engineer at Rivian
- Dylan McKillip, August 2019 – May 2020, currently a test engineer at Brooks Automation
- John Trainor, aerospace engineering class of 2021 (WPI), currently a design engineer at Triton Space Technologies, LLC
- Nathaniel Rutkowski, aerospace engineering class of 2021 (WPI), currently a propulsion engineer at Firehawk Aerospace
- Kaitlin Barron, mechanical engineering class of 2022 (WPI)
- Shannon O’Connor, mechanical engineering class of 2022 (WPI), NASA LaRC summer intern (additive manufacturing research), Summer and Fall 2021
- Caitlin Kean, mechanical engineering class of 2022 (WPI)
- Nathan Maldonado, mechanical engineering class of 2022 (WPI)
- Daniel Marsh, mechanical engineering class of 2022 (WPI)
- Adrianna Yuen, mechanical engineering class of 2024 (WPI)
- Samantah Castellano, mechanical engineering class of 2024 (CMU)
- Meenakshi Sundrum, mechanical engineering, engineering and public policy, class of 2024 (CMU)
- Brenna Slomsky, mechanical engineering class of 2024 (CMU)
- Charlotte Ng, materials science and engineering, engineering and public policy, class of 2024 (CMU)