Additive Manufacturing of Metals:
ICME Gaps: Material Property and Validation Data to Support Certification: Data Applications: Material Property and Validation Data to Support Certification
Sponsored by: TMS: Integrated Computational Materials Engineering Committee, TMS Additive Manufacturing Bridge Committee
Program Organizers: Joshua Fody, NASA Langley Research Center; Edward Glaessgen, NASA Langley Research Center; Christapher Lang, NASA Langley Research Center; Greta Lindwall, KTH Royal Institute of Technology; Michael Sansoucie, Nasa Marshall Space Flight Center; Mark Stoudt, National Institute of Standards and Technology
Tuesday 2:00 PM
October 19, 2021
Room: A114
Location: Greater Columbus Convention Center
Session Chair: Mark Stoudt, NIST; Albert To, University of Pittsburgh; Seth Strayer, University of Pittsburgh
2:00 PM Invited
Lessons Learned from Calibration and Validation of Process Models for Laser Powder Bed Fusion: Albert To1; Florian Dugast1; Seth Strayer1; Wen Dong1; Xuan Liang1; Qian Chen1; Hai Tran1; Shawn Hinnebusch1; Xavier Jimenez1; 1University of Pittsburgh
This talk presents several lessons learned from calibration and validation of process modeling for laser powder bed fusion (L-PBF) including both thermal, thermomechanical, and inherent strain models. First, the validity of using in-situ thermocouple and ex-situ optical microscopy measurement to calibrate thermal process modeling at both the mesoscale (scan-wise) and part scale will be discussed. The need for high temperature material properties in the process simulation model will also be highlighted. Second, we will examine the validity of using double cantilever structure and X-ray diffraction experiments to validate residual stress predicted by process simulation. Third, we will discuss the difficulty in conducting testing to directly obtain as-built fracture toughness of L-PBF material and propose an integrated simulation and modeling approach to overcome this difficulty.
2:30 PM
Transferability of Terrestrial Development of Metal Additive to Extraterrestrial Applications: Judy Schneider1; 1University of Alabama at Huntsville
As terrestrial applications of metal AM are expanding, space exploration is considering this technology for extraterrestrial fabrication using in-situ resources. In printing parts terrestrially, oxides are inherently present due to our oxidizing atmosphere. Often overlooked in the post processing of printed AM metals, is the contribution of these oxides to the resulting microstructural evolution and hence mechanical properties. This presentation will consider the role of oxides in metal AM processing and how the absence of an oxidizing atmosphere will affect metal AM printing and post processing.
2:50 PM Invited
ICME Gap Analysis for Materials Design and Process Optimization in Additive Manufacturing: Wei Xiong1; 1University of Pittsburgh
Additive manufacturing is a disruptive technique to release design freedom in alloy components. However, materials and processing design for additive manufacturing also introduces new challenges due to different process-structure-property relationships. In this talk, we will perform an ICME (integrated computational materials engineering) gap analysis based on studies of alloys prepared by different additive manufacturing techniques, including powder bed fusion, powder-based directed energy deposition, and wire-arc additive manufacturing. The differences in the structure-property correlations due to various manufacturing processes will be discussed. Post-processing and their sequence on mechanical performance, such as fatigue resistance, will be emphasized. Furthermore, we will explore opportunities in microstructure engineering of steel and superalloys for additive manufacturing and its post-processing. Conventional casting alloy studies are used to benchmark such an ICME gap analysis. The research performed in the same alloy system using different manufacturing techniques calls for the ad-hoc post-processing design as well as uncertainty quantification.
3:20 PM Invited
Enabling Quality Assurance by Completing the Process-Property-Performance Paradigm for Additive Manufacturing: Peter Collins1; 1Iowa State University
The promise of quality assurance is exciting - ensure that a process is sufficiently well-understood through data, theory, and accurate models to predict, within a degree of confidence, that a given material state will be produced with an expected set of properties and performance. This presentation will describe, by way of examples, the state-of-the-art related to quality assurance, as well as delve into the areas that require more work - especially related to in-situ and ex-situ nondestructive evaluation methods. Relative to the state-of-the-art, examples related to multiple processes will be given, around a common class of materials (titanium-based alloys). We will demonstrate process modeling, microstructural modeling, and full modeling of properties. It is necessary to characterize the materials state at scale, and new techniques will be discussed. Lastly, the possible NDE methods for in-situ and ex-situ techniques will be presented.
3:50 PM
An ICME Approach for Designing Appropriate Heat Treatments in Additively Manufactured Nitrogen Atomized 17-4PH Stainless Steel: James Zuback1; Mark Stoudt1; Daniel Gopman1; Maureen Williams1; Carelyn Campbell1; 1NIST
Appreciable amounts of dissolved nitrogen in 17-4PH stainless steel introduce metallurgical challenges by stabilizing austenite and inhibiting the formation of martensite during post-process heat treatment. Alloy chemistry variations within specifications can add further complexity and significantly alter the heat treatment response. Here, an integrated computational and experimental approach is used to elucidate the competing factors for designing appropriate post-processing routes beyond ordinary heat treatments for wrought materials. The work focuses on tailoring martensite fractions for a given alloy composition prior to aging. A suite of Calphad based tools are used to track nitrogen distributions, simulate secondary phase precipitation, and predict transformation temperatures during post-processing steps. These results guide targeted experiments to test heat treatment designs, and extensive microstructural characterization provides validation and feedback for improving model predictions. Findings suggest that a universal heat treatment protocol is not suitable for the variety of powder feedstocks and additive manufacturing process combinations available.
4:10 PM Keynote
Critical Issues and Gaps in Testing and Characterization Data for Computational Materials in Qualification and Certification of Additively Manufactured Metallic Materials: Michael Gorelik1; Edward Glaessgen2; 1Federal Aviation Administration; 2NASA Langley Research Center
Computational materials-based approaches that provide greater understanding of process intensive manufacturing processes (e.g., additive manufacturing) and the performance of the resulting components are emerging as an enabler for more flexible and efficient methods for Qualification and Certification (Q&C). To ensure effective application of such methods, the appropriate regulatory requirements need to be considered, including a common requirement that “test evidence is needed to support analysis.” Motivated by these requirements and opportunities, NASA and the FAA have established the Computational Materials for Qualification and Certification (CM4QC) steering group comprised of representatives from the aviation industry, government regulatory and research organizations, and academia. We will discuss the industry needs and regulatory considerations that motivate this national effort and provide an update on CM4QC’s progress toward development of a roadmap for computational materials approaches for Q&C with focus on gaps in testing and characterization data needed for developing simulation input and validation.