Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development: Functional Materials and W-based Systems
Program Organizers: Prashanth Konda Gokuldoss, Tallinn University of Technology; Jurgen Eckert, Erich Schmid Institute of Materials Science; Zhi Wang, South China University of Technology
Monday 2:00 PM
October 10, 2022
Room: 301
Location: David L. Lawrence Convention Center
2:00 PM
Different Additive Manufacturing Routes for Magnetic Shape Memory Alloys: Markus Chmielus1; Pierangeli Rodriguez de Vecchis1; Erica Stevens1; Aaron Acierno1; Jakub Toman1; 1University of Pittsburgh
Ni-Mn-Ga-based ferromagnetic shape memory alloys have been recently additive manufactured by different beam- and non-beam-based methods such as binder jet 3D printing, direct laser deposition, selective laser melting, and 3D ink printing. The as-manufactured and final microstructures and properties of each of these fundamentally different additive manufacturing (AM) techniques results are very different as well and can be exploited differently. While energy-beam-based AM methods melt feedstock powder and build dense as-printed parts, non-energy-beam-based methods result in highly porous green samples. Independent of the AM methods, post-AM processing is needed for magnetic shape memory alloys to either homogenize highly segregated microstructures or to (partially) densify porous green structures. In this talk, the microstructures and properties of AM Ni-Mn-Ga magnetic shape memory alloys and post-processing routes will be compared, and paths to functionality will be discussed.
2:20 PM
Towards the Laser-based 4D Printing of Ni-Mn-Ga Magnetic Shape Memory Alloy Actuators: Ville Laitinen1; Kari Ullakko1; 1LUT University
Ni-Mn-Ga-based magnetic shape memory (MSM) alloys can exhibit large reversible magnetic-field-induced strains of ~6-12%, making them a promising actuation material for small devices in which traditional mechanisms and piezoelectric materials would be impractical. Recent investigations have demonstrated the feasibility of laser powder bed fusion (L-PBF) for the additive manufacturing of functional polycrystalline Ni-Mn-Ga that can, after the grain boundary constraints have been sufficiently reduced, develop up to 5.8% reversible magnetic-field-induced strain. Additionally, the chemical composition of L-PBF-built Ni-Mn-Ga can be precisely changed in situ by adjusting the L-PBF process parameters to control the selective evaporation of Mn, enabling the in situ control of the crystal structure and the resulting MSM-related properties. The reported results open new avenues for the explorative development of polycrystalline-based MSM devices with geometric freedom and locally (within the device itself) tailored functional properties.
2:40 PM
Binder Jet Additive Manufacturing Process Parameters Effect on Magnetic Performance of Fe-50Ni Alloy: Emrecan Soylemez1; Emre Sari2; Emre Durna3; Baris Kirim1; 1Istanbul Technical University; 2Core Electronics; 3Aselsan Inc.
Binder jet additive manufacturing enables manufacturing complex geometries for a variety of materials to enable innovative designs. Additively manufactured soft magnetic alloys can induce desired magnetic performance with a tailored design may enhance performance of demanding electrical vehicles, machines, motors, etc. In this study, binder jet additive manufacturing of Fe-50Ni soft magnetic permalloy is employed to characterize the effects of printing parameters on green part details and heat treatment effects on density and magnetic characteristics of Fe-50Ni. The electrical and magnetic properties are characterized by a low frequency test bench to estimate BH curves and core loss behavior of manufactured core specimen. Frequency domain response of the core loss and BH curves is also revealed. Obtained results are compared with a commercial core to understand the gap between the current manufacturing methods. Understanding the magnetic characteristics of the printed Fe-50Ni alloy serves to the tailored complex designs of permalloy parts.
3:00 PM
Embedding Information in Additively Manufactured Metals via Magnetic Property Grading for Traceability and Counterfeiting Prevention: Deniz Ebeperi1; Daniel Salas Mula1; Ibrahim Karaman1; Raymundo Arroyave1; Richard Malak1; 1Texas A&M University
Counterfeiting is a significant problem in global product market which has social and economic consequences, such as fiscal losses, failure of investments and unemployment. According to International Commission of Commerce in 2022, the total value of counterfeit products will reach $2.3 trillion, and their negative impact on global economy will be $4.2 trillion while putting 5.4 million employments at stake. We have recently developed a cost-effective countermeasure for counterfeiting, by embedding information as hidden magnetic barcodes via direct energy deposition of stainless steels with different magnetic properties. The local magnetic flux was measured in fabricated parts to obtain a magnetic flux intensity map, clearly revealing the embedded magnetic barcode. A comparison between microstructure of different stainless steels and magnetic flux intensities revealed the effects of process parameters on magnetic response. Optimization of processing parameters were discussed in the light of the challenges associated with incorporating this technique in practice.
3:20 PM Break
3:40 PM
Crack Mitigation Strategies In Laser Powder Bed Fusion of Pure Tungsten: Philip Depond1; Maria Stranza1; Shiqi Zheng2; Alberico Talignani2; Morris Wang2; Jianchao Ye1; 1Lawrence Livermore National La; 2UCLA
Laser Powder Bed Fusion (LPBF) of refractory materials pose a unique challenge for the manufacturing of defect free structures. The high thermal diffusivity of tungsten, along with its high melting temperature and high ductile-to-brittle transition temperature (DBTT) has made it difficult to find a processing window for defect free structures. A fundamental understanding of crack formation and mitigation strategies is an active area of research. Here we present efforts to reach high density, >95%, and low crack density tungsten using LPBF. We use a custom built LPBF system with a high temperature heating stage to investigate the effects of up to 1000C pre-heating on the processing of pure Tungsten. Various scan strategies are compared, and thermo-mechanical modeling gives insights into the evolution of temperature and strength during printing. Mechanical properties and the resulting microstructure of as-built parts are reported.
4:00 PM
LPBF of Tungsten Heavy Alloys: Matthew Feurer1; Elias Jelis1; 1US Army DEVCOM AC
The U.S. Army is interested in the development of high density alloys (>15 grams/cm3) to enhance target penetration. Laser powder bed fusion is a manufacturing method to produce complex geometries to maximize effectiveness for lethality. There has been limited success with laser powder bed fusion tungsten heavy alloy at lower binder content (<10 wt%) for small size test coupon after post processing (Liquid Phase Sintering). Therefore, higher alloy content material systems were explored in this study. Material compositions included W-20 wt% Fe, W- 14 wt% Ni- 6 wt% Fe, and W-Ta powder blends. The manufacturability of the different materials were evaluated on the smaller EOS M100 to minimize the use of metal powder. This will determine whether or not the material system has the potential to be scaled up to larger systems such as EOS M290 or equivalent in the future. Powder properties and microstructure of printed material are evaluated for each material system.
4:20 PM
Processing of High Quality Tungsten Through Electron Beam Melting: Michael Kirka1; Chris Ledford1; Patxi Fernandez-Zelaia1; 1Oak Ridge National Laboratory
The processing of pure refractory metals through additive manufacturing modalities is often difficult due to the materials sensitivities to high ductile-to-brittle transition temperatures and the high energy densities necessary to densify the materials. To be discussed is the processing science approaches that yield high quality (crack free and >99% dense) pure tungsten. Further, microstructure and mechanical characterization of the material will be discussed, with the impact of the as-built textures on the tensile performance of the material at elevated temperatures.