2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Special Session: Defense Manufacturing
Program Organizers: Joseph Beaman, University of Texas at Austin
Tuesday 1:30 PM
August 13, 2024
Room: Salon B
Location: Hilton Austin
Session Chair: James Li, University of Texas Rio Grande Valley
1:30 PM
America's Additive Foundry Consortium: Enabling High Deposition Rate Metal Additive Manufacturing to Secure U.S. Supply of Tactical Alloys: James Li1; Joseph Beaman2; Thomas Kurfess3; 1University of Texas Rio Grande Valley; 2University of Texas at Austin; 3Virginia Tech
The America’s Additive Foundry (AAF) Consortium, a DoD funded coalition to secure U.S. supply of tactical alloys through Additive, Hybrid, and Intelligent Manufacturing to address casting and forging (C&F) supply chain issues facing the U.S. military. AAF seeks to secure these supply chains by 1) developing novel materials and processes for components traditionally manufactured using C&F that leverage metal additive, hybrid, and convergent manufacturing; 2) offering certificate/training programs to members of the academic and industrial sector that upskill and reskill the incumbent workforce; 3) serving as a regional tech demonstration hub to expose modern technologies to small and medium local manufacturers. AAF provides localized technical support for innovation, incubation, commercialization, and implementation of proposed AAF technologies.
1:50 PM
Directed Energy Deposition for Dispersion-strengthening of Alloys: Monsuru Ramoni1; 1Navajo Technical Univeristy
Dispersion-strengthened alloys (ODA) feature a metal matrix with dispersed nanoclusters of oxides, nitrides, and carbides, imparting enhanced heat resistance, strength, and ductility. These attributes render ODA vital materials for challenging environments, notably in defense applications. However, achieving a dense dispersion of nanoclusters poses a significant challenge. Directed Energy Deposition (DED), an additive manufacturing process, offers precise control over the energy input over gas and metal deposition, potentially facilitating the formation of nanoclusters within the metal matrix.This project investigates DED parameters, including laser power and powder feed rate, to promote the formation of oxides during printing, thereby enhancing the dispersion strengthening of superalloys.
2:10 PM
Laser Powder Bed Fusion of Nickel Aluminum Bronze in Nitrogen Environment: Joseph Turner1; Jazmin Ley1; Wen Qian1; Charles Nguyen2; Sean Orzolek2; 1University of Nebraska-Lincoln; 2Naval Surface Warfare Center, Carderock Division
Nickel aluminum bronze (NAB) is a unique material that provides high strength-to-weight ratio and high corrosion resistance making it ideal for defense and commercial marine applications. Laser powder bed fusion (LPBF) as an additive manufacturing technology offers superior surface finish but atmospheric conditions during LPBF play an important factor in attaining fully dense components. In this presentation, LPBF process development is described to manufacture high-density NAB components with porosity as low as 0.86% (Archimedes)/~ 0.01% (X-ray computed tomography). Although manufacturing was done in a nitrogen atmosphere, components were created without evidence of aluminum nitride (AlN) formation based on X-ray diffraction measurements. The presence of AlN could lead to material embrittlement and subsequent microcrack initiation upon loading. Additional process characterization results include melt pool evaluation, microstructure examination, residual stress investigation, and ultrasonic measurements. The use of LPBF with nitrogen atmosphere offers greater flexibility for component production from NAB and related alloys.
2:30 PM
Advancements in Modeling Techniques for High-rate Deposition in Metal Additive Manufacturing: A Review: Santosh Rauniyar1; Mathew Farias1; Ben Xu1; 1University of Houston
Modeling and numerical simulation provides a comparatively low-cost method in understanding the complex interactions in the powder based directed energy deposition (DED) process. Physical phenomena occurring at different length scales – such as grain growth at the micro-scale, temperature changes and evolution of melt pool geometry at the meso-scale, and temperature distribution and changes in residual stress at the macro-scale are challenging to solve through a single model. Studies have employed both separate models as well as coupled techniques to explain these phenomena in DED in greater depth. Once a numerical model is established and validated, it can be further used to optimize parameters for specific purpose, saving both time and costs for experiments while providing insight into how changes in parameters affect the printed part. This paper aims to review the current status of the modeling techniques and numerical simulations utilized for the DED process.
2:50 PM
Investigation of Process Parameters to Fabricate TiWMo Refractory Medium Entropy Alloy via Selective Laser Melting on Different Substrate Materials: Lindsey Salazar1; Abdullah Jabir1; James Li1; 1University of Texas Rio Grande Valley
Refractory medium entropy (RMEA) alloy (TiWMo) was fabricated by selective laser melting (SLM) process from elemental powder on different substrates (steel, titanium and tungsten). The results indicate that titanium substrate successfully formed TiWMo alloy. While other substrate showed some brittle nature during fabrication. With the highest energy density 350 j/mm3, the calculated porosity was lowest. Scanning electron microscope (SEM) showed less unmelted tungsten with increasing energy density. Design of experiment (DoE) analysis presents that scanning speed has little more contribution to have less porosity and unmelted tungsten than laser power. Single phase BCC solid solution was observed by XRD. Highest microhardness 633HV was achieved at highest energy density 350 j/mm3.
3:10 PM Cancelled
Impact of Electron Beam Power and Scanning Speed on Microstructural Properties of Copper Alloy GRCop-42 for Extreme Environment Applications: Monsuru Ramoni1; 1Navajo Technical Univeristy
This study explores electron beam additive manufacturing (EBAM) of Copper Alloy GRCop-42, aiming to address the challenges faced by laser-based additive manufacturing processes due to the high thermal conductivity and reflectivity of copper and its alloys. Electron beams, characterized by their higher energy density and superior penetration capabilities, present a promising alternative for overcoming these processing difficulties. The primary objective is to investigate the influence of electron beam parameters, specifically electron beam power and scanning speed, on the microstructure, grain formation, precipitate morphology, composition, and crystal structure during component fabrication. The findings have the potential to significantly enhance the additive manufacturing of copper alloys, especially for demanding applications such as defense.
3:30 PM
A Review of the Ceramic Reinforced Ni-based Superalloys: Abdalla Elmaghraby1; AMM Nazmul Ahsan1; James Li1; 1University of Texas Rio Grande Valley
Superalloys based on nickel are an intriguing class of materials that exhibit exceptional performance in a variety of challenging environments, including corrosive media, elevated temperatures, and high pressure. This group of alloys is one of the promising options for the petrochemical, aerospace, and aviation industries and the defense sector. However, in certain situations, the industry's needs are greater than the progress made in alloys and superalloys, necessitating further research into alternative methods of improving material properties. Recently, ceramics have been used to fabricate metal matrix composites (MMCs) by adding them as reinforcements to the metal/alloy matrix fusing the properties of both alloys and ceramics. Given that the properties obtained from the alloy MMCs are significantly enhanced, a new chapter in nickel-based superalloys is emerging. This review article provides a comprehensive understanding of the research findings on ceramic-reinforced nickel-based superalloy MMCs, as well as future research trends.