Naval/Maritime Applications of Additively Manufactured Parts: Design and Experimental Approaches: Naval/Maritime Applications of Additively Manufactured Parts: Design and Experimental Approaches
Program Organizers: Cindy Waters, Naval Surface Warfare Center Carderock Div; Caroline Vail, Naval Surface Warfare Center, Carderock; Marc Zupan, UMBC -University of Maryland, Baltimore County
Tuesday 2:00 PM
November 3, 2020
Room: Virtual Meeting Room 7
Location: MS&T Virtual
Session Chair: Cindy Waters, Naval Surface Warfare Center Carderock
2:00 PM
Introductory Comments: Naval/Maritime Applications of Additively Manufactured Parts: Design and Experimental Approaches: Cindy Waters1; 1Carderock Division Naval Surface Warfare Center
Introductory Comments
2:05 PM
Repeatability and Performance Prediction of Additively Manufactured 17-4 Stainless Steel: Julianna Posey1; Michael Duffy2; Caroline Vail3; Marc Zupan2; 1University of Maryland, Baltimore County ; 2University of Maryland, Baltimore County; 3University of Maryland, Baltimore County;Naval Surface Warfare Center, Carderock Division
Research into additive manufacturing (AM) techniques as a viable process for next-generation marine vessels has identified various benefits for using precipitation hardened (PH) stainless steel alloyed components, including increased corrosion resistance and strength. In this work, thin fin 17% Chromium - 4% Nickel (17-4 PH) alloy structures of three different thicknesses (1-3 mm) and four different build angles (45-90 degrees) were manufactured using the EOS-M290 directed energy deposition AM process. The samples' mechanical and physical properties are assessed by surface roughness measurements of "upskin" and "downskin" surfaces. Vickers hardness testing is coupled with microtensile testing of samples harvested along the fin heights. Variations in fin microstructure are identified, characterized, and linked to measured mechanical properties. The impact of the AM build geometry and processing parameters is connected to the microstructure and materials response.
2:25 PM
Additive Friction Stir Deposition for Naval/Maritime Applications: Mackenzie Perry1; Hang Yu1; 1Virginia Polytechnic Institute
Additive friction stir deposition (AFSD) is a large scale, solid-state additive manufacturing technique that lends itself to many naval applications. With further research, an AFSD machine could be used shipboard to build custom parts with desirable properties, coat large surfaces for corrosion prevention, or repair in-service components. As opposed to melting-based metal additive manufacturing, AFSD uses friction from tool rotation to deform and deposit the feed material. That promotes strong interface bonding, no detectable porosity, and isotropic, fine grained microstructures which all lead to good mechanical properties. Based on dissimilar material cladding and tracer experiments, physical insights into the material flow at the interface and within the deposition zone have been obtained, wherein X-ray computed tomography and electron backscatter diffraction reveal the 3-D morphology of the deposited material and the microstructure evolution. The asymmetric bowl-shaped interface is characterized by interlocking features and significant macroscopic material mixing.
2:45 PM
Additive Manufacturing of a Lifeboat Hook System with a Functionally Dynamic Mechanism: Ulanbek Auyeskhan1; Namhun Kim2; Van Loi Tran1; Eunhei Cho1; Dong-Hyun Kim1; 1KITECH; 2Ulsan National Institute of Science and Technology
Design for Additive Manufacturing (DFAM) is enabling us to conduct effective part consolidation of complex assembled products. Most of the recent AM studies have attempted to consolidate only static parts such as brackets and valve bodies, however, demand for dynamic systems is expected to increase, too. Our novel study challenges to redesign and validate a lifeboat hook system with a dynamic operation mechanism by fully leveraging a conventional part consolidation concept and involving respective constraints.The conventional part consolidation may not be sufficient for the system with dynamic mechanisms. Additionally, the lifeboat hook system is undergone a heavy loading during its operation. Thus, taking into account these constraints the number of hook components were decreased by 55%. FEM analysis results reveal that AM hook components perform better than an original design. Lastly, a scaled-down version of the consolidated hook system was successfully built by a PBF machine for design verification.
3:05 PM
Direct Tension and Fatigue Characterization of AM Ti-6Al-4V Defects: A Microsample Approach: Joao Santos1; Michael Duffy1; Steven Storck2; Marc Zupan1; 1University of Maryland, Baltimore County; 2University of Maryland, Baltimore County; The Johns Hopkins Applied Physics Lab
The Navy has an interest in being able to use Additively Manufactured (AM) parts on their Naval air fleet. By using AM parts, the Navy can improve fleet readiness and increase the speed of maintenance with on-demand part reproduction. In this study, AM Ti-6Al-4V with intentionally induced defects created via direct metal laser sintering are mechanically tested using both direct tension and fatigue MicroTensile testing techniques. These defects are produced by varying the process parameters away from standard processing levels, creating both keyhole and lack of fusion type defects. The effect of the defect type, size shape and level of defects, and as-built material microstructure on measured mechanical performance will be presented. The study has determined that not only is the volume fraction of defects important, but the source/type of the defect is critical to material mechanical performance.