N25A-T004 TITLE: Material System Design Tool to Enable Functionally Graded Materials

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Computing and Software;Advanced Materials;Sustainment

OBJECTIVE: Develop an Integrated Computational Material Engineering (ICME)-based material system design tool for multi-material functionally graded materials (FGMs).

DESCRIPTION: Additive manufacturing (AM) is a process of "printing" a 3D solid object from a digital model and enables the production of geometrically complex components that would be too costly, time-consuming, and/or impossible to produce by other manufacturing processes. However, most of the current AM technologies have not yet begun to achieve their full potential. One example of this is the ability to use multiple materials to fabricate components that are multifunctional. Functionally graded materials (FGMs) are materials whose composition (elements and/or phases) or microstructure (grain size, shape, and/or orientation) varies across a volume. The gradient of material properties results in unique mechanical and functional properties.

FGMs can enable multifunctional material systems with multiple functions. Multi-material FGMs can strategically allocate properties such as strength, density, and wear resistance over a single part. For example, wear and corrosive resistant alloys have been placed on tool steel die/mold for performance enhancements to elongate service life [Refs 1–3]. However, current multi-material AM processes produce discrete and relatively thick layers, which make the creation of a smooth gradient challenging.

Additionally, while current multi-material AM processes are sufficient for some material combinations (e.g., deposition of stainless steel onto low-carbon steel), other material combinations have poor compatibility (e.g., Ti-6Al-4V and Inconel 718). A combination of material compatibility and residual stresses from processing can result in cracking and delamination of layers. However, a true FGM with gradual transition from one material to the next can mitigate this issue. The results can be further improved if a buffer material is incorporated into the FGM. For example, Thiriet et al. (2019) demonstrated the potential of fabricating an FGM using Ti-6Al-4V and Inconel 718 by using a molybdenum buffer layer [Ref 5]. Therefore, the buffer material selection will be critical for FGM design and fabrication for certain material combinations.

An analytical toolset to design functionally graded material systems is being sought to improve mechanical performance (strength, ductility, fatigue, fracture toughness) and environmental protection (corrosion, wear/fretting) for structural and subsystem components on U.S. Navy and Marine Corps aircraft. More specifically, FGMs are desired to provide transition zones from a substrate material to a desired coating material to reduce stiffness mismatches between the two materials to promote a longer service life via reducing stresses. The ICME-based analytical tool must address material selection by considering the compatibility of material properties, such as thermal expansion coefficients, as well as the need for buffer materials. Material selection must also consider undesirable high-temperature chemical reactions may result in intermetallics that may degrade the mechanical properties of the material system. The analytical tool must also predict the thicknesses of a transition zone for a FGM and any required buffer materials, and must consider different types of gradients (e.g., continuous and discrete gradients). The material system design must also ensure the fulfillment and optimization of application requirements, such as the overall strengths, fatigue, fracture toughness, weight, corrosion resistance, wear resistance, thermal and electrical conductivity, and so forth, of the fabricated FGM part.

PHASE I: Develop, design, and demonstrate feasibility of an ICME-based material system design tool to facilitate the fabrication of multi-material FGMs once the based material and target material(s) are identified. The focus of Phase I must be to explore the feasibility of a robust methodology for designing the proper FGM material system, including all buffer materials. Such an FGM material system design tool must be demonstrated by fabricating at least two different FGM samples with buffer materials. FGM samples must be designed and fabricated to satisfy different and complementary/supplementary functionalities, such as strength, fatigue, fracture toughness, density, corrosion, or wear/fretting resistance, and so forth. The produced FGM samples must be evaluated based on microstructure and mechanical properties, such as hardness and tensile and fatigue strength. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Fully develop and validate the prototype tool with various material systems and applications, including more performance requirements, such as fracture toughness, fatigue resistance, corrosion resistance, and so forth. The design tool must be fully demonstrated with at least five separate FGM examples that are applicable and useful for Navy applications. The developed methodology and tool must be demonstrated for its robustness in handling various applications, including the cases that selected base material and the target material(s) are not non-compatible, thus buffer material(s) is needed. FGM samples must be fabricated and validated through proper testing, including mechanical and environmental testing to validate the multi-functional requirements.

PHASE III DUAL USE APPLICATIONS: Fully develop the FGM design and fabrication tool to produce naval aircraft components that can be integrated into the fleet. Conduct final component level testing to fabricate the FGM parts with geometry and material properties of AM components meeting the Navy’s specifications.

The process will be directly applicable to a wide range of AM process applications due to the high amount of usage of AM parts in the commercial/private aerospace industry. The proposed process will allow the industry to apply the benefits of AM technology to many critical aircraft components.

REFERENCES:

1. Riabkina-Fishman, M.; Rabkin, E.; Levin, P.; Frage, N.; Dariel, M. P.; Weisheit, A.; Galun, R. and Mordike, B. L. "Laser produced functionally graded tungsten carbide coatings on M2 high-speed tool steel." Materials Science and Engineering: A, 302(1), 2001, pp. 106-114. https://doi.org/10.1016/S0921-5093(00)01361-7

2. Zhang, X.; Pan, T.; Li, W. and Liou, F. "Experimental characterization of a direct metal deposited cobalt-based alloy on tool steel for component repair." Jom, 71, 2019, pp. 946-955. https://doi.org/10.1007/s11837-018-3221-5

. Cui, C.; Guo, Z.; Liu, Y.; Xie, Q.; Wang, Z.; Hu, J. and Yao, Y. "Characteristics of cobalt-based alloy coating on tool steel prepared by powder feeding laser cladding." Optics & Laser Technology, 39(8), 2007, pp. 1544-1550. https://doi.org/10.1016/j.optlastec.2006.12.005

4. Choi, J. W.; Kim, H. C and Wicker, R. "Multi-material stereolithography." Journal of Materials Processing Technology, 211(3), 2011, pp. 318-328. https://doi.org/10.1016/j.jmatprotec.2010.10.003

5. Thiriet, A.; Schneider-Maunoury, C.; Laheurte, P.; Boisselier, D. and Weiss, L. "Multiscale study of different types of interface of a buffer material in powder-based directed energy deposition: example of Ti6Al4V/Ti6Al4V-Mo/Mo-Inconel 718." Additive Manufacturing, 27, 2019, pp. 118-130. https://doi.org/10.1016/j.addma.2019.02.007

6. Alkunte, Suhas; Fidan, Ismail; Naikwadi, Vivekanand; Gudavasov, Shamil; Ali, Mohammad Alshaikh; Mahmudov, Mushfig; Hasanov, Seymur and Cheepu, Muralimohan. "Advancements and Challenges in Additively Manufactured Functionally Graded Materials: A Comprehensive Review." Journal of Manufacturing and Materials Processing 8, no. 1, 2024: 23. https://doi.org/10.3390/jmmp8010023

7. Fathi, Reham; Wei, Hongyu; Saleh, Bassiouny; Radhika, N.; Jiang, Jinghua; Ma, Aibin; Ahmed, Mahmoud H.; Li, Qin and Ostrikov, Kostya Ken. "Past and present of functionally graded coatings: Advancements and future challenges." Applied Materials Today 26, 2022: 101373. https://doi.org/10.1016/j.apmt.2022.101373

KEYWORDS: Functionally Graded Materials; Additive Manufacturing; Multi-Material Design; High-Fracture Resistance; Integrated Computational Material Engineering; Corrosion

TPOC 1: Joshua Piccoli
(443) 624-398
Email: [email protected]

TPOC 2: Madan Kittur
(301) 342-029
Email: [email protected]

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