ABSTRACT Today’s combat vehicle designs are largely constrained by traditional manufacturing processes, such as machining, welding, casting, and forging. Recent advancements in 3D-Printing technology offer tremendous potential to provide economical, optimized components by eliminating fundamental process limitations. The ability to re-design suitable components for 3D-printing has potential to significantly reduce cost, weight, and lead-time in a variety of Defense & Aerospace applications. 3D-printing will not completely replace traditional processes, but instead represents a new tool in our toolbox - from both a design and a manufacturing standpoint

Deters, Jason

FLASH® BAINITE: ROOM TEMPERATURE WELDABLE ULTRA HARD 600, HIGH HARD 500, AND ADVANCED HIGH STRENGTH STEEL FOR A-CAB

2024-01-3743

11/15/2024

ABSTRACT Flash® Bainite Processing employs rapid thermal cycling (<10s) to strengthen commercial off the shelf (COTS) steel sheet, plate, and tubing into Ultra Hard 600 Armor, High Hard 500 Armor, and advanced high strength steel (AHSS). In a continuous process, induction technology heats a narrow segment of the steel cross section in just seconds to atypically high temperature (1000-1300°C). Quenching substantially immediately follows. A report by Benet Labs and Picatinny Arsenal, investigating a less mature flash technology in 2011, surmised that the novel flash bainite process for steels has the potential to reduce cost and weight while also enhancing mechanical performance [1]. Receiving five financial grants, the US Dept of Energy has greatly matured flash technology in the last few years and its metallurgical understanding in collaboration with Oak Ridge National Lab and others. DOE has named Flash Bainite as the “SBIR Small Business of the Year” in May 2018 and awarded a Phase 3

Cola, Gary M

Scan Sequence Optimization for Reduced Residual Stress and Distortion in LPBF Additive Manufacturing – An AISI 316L Case Study

2024-01-4051

11/15/2024

ABSTRACT Laser powder bed fusion (LPBF) additive manufacturing often results in defective parts due to non-uniform temperature distribution during fabrication. To mitigate this issue, the authors recently introduced SmartScan, an intelligent method that employs modeling and optimization to generate scan sequences that improve temperature uniformity. However, the previous version of SmartScan could only be applied to single layers. This paper presents an extension of SmartScan to three-dimensional parts by adjusting the thermal model and optimization objective. Through simulations and experiments involving fabricating AISI 316L stainless steel parts, the study demonstrates that the proposed SmartScan approach significantly improves temperature uniformity, reduces part distortion, and mitigates residual stress, as compared to conventional heuristic sequences. Citation: C. He, C. E. Okwudire, “Scan Sequence Optimization for Reduced Residual Stress and Distortion in PBF Additive

He, Chuan, Okwudire, Chinedum E.

2024-01-3744

11/15/2024

ABSTRACT Friction stir welding is a solid state joining technique in which no melting of the metals is involved. The technique is very attractive for aluminum alloys due to the low heat input involved in the process, which leads to improved mechanical properties as compared to conventional fusion welds. In this work, different aluminum series alloys were friction stir welded together. The aluminum alloys consisted of a solid solution/strain hardened aluminum alloy 5083-H131, and precipitation strengthened aluminum alloys 2139-T8 and aluminum 7085-T721. The joint combinations were aluminum alloys 5083-H131 to 7085-T721, aluminum alloys 2139-T8 to 7085-T721, and aluminum alloys 5083-H131 to 2139-T8. Their mechanical properties were analyzed and compared to base metal properties. Optical microscopy was used to analyze the grains in the welds. Good mixing of the different aluminum alloys was optically observed in all of the welds, which lead to good joint properties, opening the

Martinez, Nelson, McDonnell, Martin

MICROSTRUCTURAL ANALYSIS AND CREEP BEHAVIOR OF 25MM THICK FRICTION STIR WELDED AA2139-T8

2024-01-3737

11/15/2024

ABSTRACT Most studies conducted on friction stir welded (FSW) Al alloys are on plates that are 2.5-7 mm thick. However, the U.S. Army utilizes materials that are 25 mm thick and greater for structure and armor. In order to properly apply FSW to Al-Cu-Mg-Ag alloys for use in next generation ground vehicles, data must be generated and available for model and simulation databases. One key type of data is the tensile-creep behavior of FSW AA 2139-T8. Creep is the time dependent, plastic deformation of a material under a constant load, usually observed at a constant temperature where T>0.3Tm. The objective of this study is to provide information regarding the tensile-creep behavior of the stir zone in comparison to the heat affected zone (HAZ) through the depth of the weld. The results from this research provide information on the effect of FSW processing on the microstructure and creep behavior. Pre- and post-deformation samples were analyzed via SEM and TEM and the results are discussed

Okeke, Uchechi, Boehlert, Carl

LEVERAGING HIGH-FIDELITY SIMULATION TO EVALUATE AUTONOMY ALGORITHM SAFETY

2024-01-3651

11/15/2024

ABSTRACT The age of large autonomous ground vehicles has arrived. Wherever vehicles are used, autonomy is desired and, in most cases, being studied and developed. The last barrier is to prove to decision makers (and the general public) that these autonomous systems are safe. This paper describes a rigorous safety testing environment for large autonomous vehicles. Our approach to this borrows elements from game theory, where multiple competing players each attempt to maximize their payout. With this construct, we can model an environment that as an agent that seeks poor performance in an effort to find the rare corner cases that can lead to automation failure

Penning, Ryan, English, James, Melanz, Daniel, Limone, Brett, Muench, Paul, Bednarz, David

PHYSICAL TESTING AND MODELING OF BOLTED AND WELDED CONNECTIONS FOR ARMORED VEHICLE MODELS

2024-01-3637

11/15/2024

ABSTRACT Protection Engineering Consultants (PEC) has performed static and dynamic-pendulum tests on bolted and welded connection sub-assemblies to generate data for development and validation of modeling approaches capable of accurately predicting the behavior of connections exposed to shock loads. The connections consisted of Rolled Homogeneous Armor (RHA) steel plates, Grade 8 bolts, and fillet welds of ER80-S wire, as typically used in armored vehicles. A summary of the forty physical tests on nine connection configurations are provided along with strain gage and Digital Image Correlation (DIC) data. The specimens were designed to have typical failure modes, i.e. bolt shear, plate tear-out, and weld shear fracture. Using these data, high-fidelity numerical models were developed, with exceptionally good comparisons to the experimental data. During the development of the numerical models, crucial modeling parameters were identified and were shown to have significant influence to the

Hadjioannou, Michalis, Barsotti, Matt, Sammarco, Eric, Stevens, David

Identification and Management of Key Characteristics in Product Development Using Model Based System Engineering

2024-01-4010

11/15/2024

ABSTRACT The International Council on Systems Engineering https://www.incose.org/ is a recognized standards body defining a system engineering knowledge-base, but this knowledge falls short of fully recognizing manufacturing in the Systems Engineering (SE) framework. To be inclusive, Manufacturing needs to join in the initiative of Model Based Systems Engineering to be relevant and succeed in the digital transformation in the field of systems engineering. This paper addresses this need in manufacturing by applying Model Based System Engineering (MBSE) to the identification and management of key characteristics so that a more relevant set of Manufacturing requirements can be introduced into the MBSE construct and help realize manufacturing resilience and become a full SE partner. Citation: “Identification and Management of Key Characteristics in Product Development Using Model Based Systems Engineering,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium

Ireland, William

Microstructure analysis of TIG welded additively manufactured prepared joints of Ni-based superalloys produced by Laser Powder Bed Fusion

2024-01-4050

11/15/2024

ABSTRACT Laser powder bed fusion (L-PBF) of entire assemblies is not typically practical for technical and economic reasons. The build size limitations and high production costs of L-PBF make it competitive for smaller, highly complex components, while the less complex elements of an assembly are manufactured conventionally. This leads to scenarios that use L-PBF only where it’s beneficial and requires integration and joining to form the final product. Today the welding process requires complex welding fixtures and tack welds to ensure correct alignment and positioning of parts for repeatable results. In this paper, both L-PBF and milled weld preparations are presented to simplify Tungsten inert gas (TIG) welding of rotationally symmetrical geometries using integrated features for alignment and fixation. All welds produced in this study passed the highest evaluation group B according to DIN 5817. Citation: Ole Geisen, Tad Steinberg, “Microstructure analysis of TIG welded additively

Geisen, Ole, Steinberg, Tad

AUTOMATED MANUFACTURING FOR AUTONOMOUS SYSTEMS SOLUTIONS (AMASS

2024-01-3925

11/15/2024

ABSTRACT The University of Delaware (UD) and the US Army DEVCOM-GVSC (GVSC) have partnered to show the feasibility of fabricating mission specific, man-packable, autonomous vehicles that are created by Computer Aided Design (CAD) and are then produced, from start-to-finish, in a single manufacturing unit-cell without human intervention in the manufacturing process. This unit-cell contains many manufacturing processes (e.g., additive manufacturing (AM), pick-and-place, circuit printing, and subtractive manufacturing) that work in concert to fabricate functional devices. Together, UD and GVSC have developed the very first mission specific autonomous vehicle that is fully fabricated in a single manufacturing unit-cell without being touched by human hand. Citation: Jacob W. Robinson, Thomas W. Lum, Zachary J. Larimore, Matthew P. Ludkey, Larry (LJ) R. Holmes, Jr. “AUTOMATED MANUFACTURING FOR AUTONOMOUS SYSTEMS SOLUTIONS (AMASS)”, In Proceedings of the Ground Vehicle Systems Engineering and

Robinson, Jacob W., Lum, Thomas W., Larimore, Zachary J., Ludkey, Matthew P., Holmes, Larry (LJ) R.

PREDICTING THE LIFE OF MILITARY VEHICLE COMPONENTS IN THE PRESENCE OF DEFECTS

2024-01-3200

11/15/2024

ABSTRACT When the components of a military vehicle are designed, consideration is given to long term durability under repeated mission applications. In reality, surface and subsurface defects have always existed in weldments, forgings, and castings. These defects came from the manufacturing process or nucleated during the life of the vehicle. These defects may grow under repeated operations, resulting in ultimate failure of parts well before the design life is achieved. In such situations, a design based on crack initiation alone will not suffice, and a fracture mechanics based fatigue should also be included to predict the design life of a part accurately. In this paper a methodology is given on how to predict the available design life given the presence of defects in different parts of a military vehicle. An example will be provided with the process to demonstrate each step of the process

Porter, William De

FLASH® 600 ULTRA HIGH HARD: ROOM-TEMP ER120S-1 WELDABILITY TEKKEN, H-PLATE, BALLISTIC, & FSP DATA FOR IMPROVED SURVIVABILITY

2024-01-3900

11/15/2024

ABSTRACT Survivability of a welded vehicle hull is directly tied to the performance of the grade of steel armor used. Selecting the highest performing grade of armor that can be welded into a specific location on a vehicle will improve survivability. While rolled homogeneous armor is the simplest to weld, challenges in welding high hard, and especially ultra high hard, are well known. Preventative measures to avoid weld cracking in vehicle structures can lead to increased costs during fabrication. Cracking of welds, both seen and unseen, in deployed vehicles directly impacts the survivability of the vehicle. Weld cracking during deployment further magnifies repair costs and leads to non-mission capable status. This analysis examines the weldability, ballistic/blast performance, and underlying metallurgy of Flash® Processed steels that have been tested by Army, Academia, and Industry. Citation: G. Cola, “Flash® 600 Ultra High Hard: Room-Temp ER120S-1 Weldability Tekken, H-Plate

Cola, Gary M

NMP–free Lithium Ion for Sustainable Manufacturing in Silent-Watch Applications

2024-01-3946

11/15/2024

ABSTRACT PPG formulates N-methyl pyrrolidone free (NMP−free) cathodes for Li−ion batteries capable of delivering sufficient power for automotive starting, lighting and ignition (SLI) as well as adequate charge capacity for powering auxiliary electronics. In this paper, NMP−free energy cathodes and power cathodes were formulated using developmental binders, and refinement of carbon/binder ratio and slurry mix procedure. Learnings from the energy and power cathode development were conceptually combined in the formulation of capacity enhanced power cathodes. These cathodes were evaluated electrochemically via power capability and rate capability testing in battery coin cells, as well as in 0.5 Ah multilayer pouch cells. Carbon content was found to be a critical factor in attaining high cold crank performance. This work represents significant steps toward potential commercialization of NMP−free cathode coated foil for Li−ion batteries. Citation: S. Esarey, A. Kizzie, C. Woodley, I. Matts

Esarey, Samuel L., Kizzie, Austin, Woodley, Christopher, Matts, Ian, Hellring, Stuart, Zhou, Zhilian, Terrago, Gina

DESIGN OPTIMIZATION OF COMBAT VEHICLE DRIVER’S SEAT USING ADDITIVE MANUFACTURING AND COMPRESSION MOLDING

2024-01-3990

11/15/2024

ABSTRACT This paper focuses on the application of a novel Additive Molding™ process in the design optimization of a combat vehicle driver’s seat structure. Additive Molding™ is a novel manufacturing process that combines three-dimensional design flexibility of additive manufacturing with a high-volume production rate compression molding process. By combining the lightweighting benefits of topology optimization with the high strength and stiffness of tailored continuous carbon fiber reinforcements, the result is an optimized structure that is lighter than both topology-optimized metal additive manufacturing and traditional composites manufacturing. In this work, a combat vehicle driver’s seatback structure was optimized to evaluate the weight savings when converting the design from a baseline aluminum seat structure to a carbon fiber / polycarbonate structure. The design was optimized to account for mobility loads and a 95-percentile male soldier, and the result was a reduction in

Hart, Robert J, Perkins, J. Scott, Blinzler, Brina, Miller, Patrick, Shen, Yang, Deo, Ankit

TOPOLOGY OPTIMZATION STUDY OF LASER POWDER BED FUSION BRACKETS TO ENABLE AM AS A SOURCE OF SUPPLY FOR DMSMS APPLICATIONS

2024-01-3991

11/15/2024

ABSTRACT The objective in this paper is to understand the challenges of making additive manufacturing a future source of supply for the Department of Defense through the redesign of a part for metal laser Powder Bed Fusion. The scope of this paper involved the redesign of a single cast-and-machined part for an Army ground vehicle system. The component was redesigned using topology optimization based on suitable replacement materials and design data from the representative part. In parallel, a brief review of AM standards identified a process to qualify the component through post-processing, non-destructive evaluation, and witness testing. Alongside this redesign analysis, a brief cost analysis was conducted to understand the cost associated with manufacturing and qualifying this part for multiple AM materials. The resulting analysis demonstrated that for this component, which was subject to high design loads, Scalmalloy, Ti-6Al-4V, and 17-4PH Stainless Steel could produce the most cost

Burke, Rory, Simpson, Timothy

MILITARY VEHICLE UNDERBODY ARMOR PLATE ATTACHMENT STUDY

2024-01-3488

11/15/2024

ABSTRACT In this paper a new bolt attachment method was explored, where the attaching bolts were divided into two sets. The first set of bolts was tightened and was used to connect the underbody plate to the hull under ordinary operations. The second set of bolts connecting the plate and the hull were not tightened and had some extra axial freedom. Under blast loading, the first set of bolts would break due to high tensile and shear loads, but the second set of bolts would survive due to extra axial freedom which allows the plate and the hull vibrate and separate from each other to a certain extent. A simulation model was developed to verify this concept. Three underbody plate-hull connection approaches were simulated and analyzed: 1) all tightened bolts, 2) some bolts not fully seated, 3) all bolts not fully seated. The simulation results show that with option 1), 100% of the bolts broke under the blast loading. With option 2) the not fully seated bolts survived and continued to

Kang., Jian, Liedke, Mark, Mason, James

STRUCTURAL ADHESIVE WITH COMBINED HIGH STRENGTH AND DUCTILITY FOR MULTIMATERIAL JOINING AND GALVANIC ISOLATION

2024-01-3735

11/15/2024

ABSTRACT A newly developed structural adhesive demonstrates a unique combination of high strength (43 ± 2 MPa) and displacement (4.7 ± 1.2 mm) in aluminum lap joint testing. Bulk material characterization of the prototype adhesive reveals its extreme ductility, with nearly 80% shear strain before failure and a 2.5-fold increase in strain energy density as compared to commercial structural adhesives. The prototype adhesive is found to maintain 67 to 82% of its initial strength under extreme environmental conditions, including at high temperatures (71°C), after high humidity (63°C hot water soak, 2 weeks), and after corrosive conditions (B117 salt spray, 1000 hours). The prototype structural adhesive is shown to also generate high strength bonds with multiple substrates, including steel, carbon fiber, and mixed material joints, while also providing galvanic isolation

Pollum, Marvin, Kriley, Joseph, Nakajima, Masa, Tan, Kar Tean, Stalker, Jeffrey, Fleischauer, Richard, Rearick, Brian

Feasibility of Joining Wrought Homogenized Armor Steel with Friction Stir Welding

2024-01-3811

11/15/2024

Abstract The United State Army employs several advanced armored combat vehicles, in a wide array of different environments, and applications. Armor steels are hard and are required to meet certain conditions to stay within the military’s specifications for armored steels. Vehicle armor is typically joined using arc welding methods. Joining via arc welding degrades armor material below specification, so alternate joining methods are being explored like Friction Stir Welding (FSW). FSW is a solid-state joining technique that utilizes a rotating pin to stir plasticized material and use a tool shoulder to forge the material into the joint. The advantages come from the reduction in peak temperature, an increase in mechanical performance, and a decrease in possible defects that occur. In this study FSW parameters were developed and used to weld Wrought Homogenous Armor (HRA) steel. The welds were subject to hardness indention, and metallographic analysis to observe an early prediction of

Evans, William, Ramirez, Antonio, McDonnell, Martin, Eff, Mike

DEVELOPMENT OF HEAT PIPE LOOP TECHNOLOGY FOR MILITARY VEHICLE ELECTRONICS COOLING

2024-01-3184

11/15/2024

ABSTRACT Current standard military vehicle thermal management systems are based on single phase air/liquid cooling. To meet increasingly stringent demands for high power electronics thermal control, two-phase cooling solutions show great potential and can satisfy the need for compact and high heat flux heat acquisition, transport and dissipation under vibration and shock conditions. One novel two-phase cooling technology that has been developed in this work is a new Heat Pipe Loop (HPL), which exploits the advantages of both heat pipes and loop heat pipes while eliminating their shortcomings. Similar to heat pipes and loop heat pipes, the HPL operates on evaporation and condensation of a working fluid and uses capillary forces in the wick for the fluid circulation. Unlike in a heat pipe, the liquid and vapor in the HPL flow in separate passages made from smooth wall tubing. This results in a low pressure drop and consequently great heat transfer capacity and distance over which the

Tang, Xudong, Zuo, Jon, Goryca, Mary

MODULAR EXHAUST DESIGN AND MANUFACTURING TECHNIQUES FOR LOW COST MID VOLUME RAPID BUILD TO ORDER SYSTEMS

2024-01-3468

11/15/2024

ABSTRACT We propose new methods to help automate the design of customizable mufflers, as well as modular manufacturing techniques targeted at mid volume quantities. A successful solution would reduce the price point of a muffler to an estimated $500 per unit for a order size between 10 and 1000 units. In the ideal case, customers would not need to inventory mufflers because lead times would be fast and managed

Nelson, Kevin, Kangas, Greg, Mattson, Steve, Hufnagel, Alan

Microstructure analysis of TIG weld joints of Ni-based superalloys produced by Laser Powder Bed Fusion

2024-01-3987

11/15/2024

ABSTRACT The industrial use of laser powder-bed fusion (L-PBF) in turbomachinery is gaining momentum rendering the inspection and qualification of certain post-processing steps necessary. This includes fusion techniques that allow to print multiple parts separately to take advantage of e.g., various print orientations and join them subsequently. The main motivation of this study is to validate the tungsten inert gas (TIG) welding process of L-PBF manufactured parts using industrial specifications relevant for gas turbines to pave the way for the industrial production of modular build setups. For this, two commonly used nickel-based super alloys for high-temperature applications, Inconel 718 and Inconel 625 are chosen. Since their defect-free printability has been established widely, we focus on the suitability to be joined using TIG welding. The process is evaluated performing microstructural examination and mechanical tests in as built as well as heat-treated samples. The welds are

Geisen, Ole, Bogner, Jan, Ghavampour, Ebrahim, Müller, Vinzenz, Eissing, Katharina

INCREASING POWER DENSITY BY ADVANCED MANUFACTURING, MATERIALS, AND SURFACE TREATMENTS

2024-01-3595

11/15/2024

ABSTRACT Track vehicle Final Drive torque transferring capacity is constrained by the availability of packaging space, weight constraints, and material / heat treat properties. These constraints create a paradigm where as the increase in load due to weight growth is inversely related to life due to fatigue. Funded under Phase II SBIR contract W56HZV-13-C-0056, Loc Performance Products, Inc. (Loc) developed manufacturing processes aligned to key selected materials and surface treatments to break through this paradigm. The results of the SBIR efforts produced an optimized Final Drive design that addressed the increasing Gross Vehicle Weight (GVW) of the Bradley Fighting Vehicle while maintaining the current Final Drive packaging space, reducing lifecycle cost and maximizing performance in terms of power density and extending the life of the product

Militello, Anthony, Fowlkes, Edward

Tech Pub Qualification Scheme Development for Arc Directed Energy Deposition Additive Manufacturing

2024-01-3808

11/15/2024

ABSTRACT A prescriptive qualification scheme was completed for Arc Directed Energy Deposition (DED) metal Additive Manufacturing (AM) processes for austenitic single-sided builds. Robotic arc DED AM qualification builds used stainless steel consumables with the gas metal arc welding - pulse (GMAW-P) process. A matrix of standard qualification builds were made to develop, evaluate, and recommend the preferred process qualification build schemes. The qualification scheme explored a range of heat inputs, deposit sizes, and deposition rates; and the effects of interpass temperature that can be a limiting productivity factor for robotic arc DED metal AM builds. The standard qualification builds evaluated the effects of thickness (thin and thick geometric build features) where the process deposit (heat input) and process build thermal features (preheat and interpass temperature) are controlled over smaller ranges. The builds were examined with both ultrasonic and radiographic inspection, and

Harwig, D.D, Mohr, W., Hovanec, S., Rettaliata, J., Hayleck, R., Handler, E, Farren, J.

PATH TO 450 PARTS QUALIFIED FOR ADVANCED MANUFACTURING

2024-01-3928

11/15/2024

ABSTRACT The United States Army is leveraging Advanced Manufacturing (AdvM) methods to solve both operational and tactical readiness gaps. AdvM includes not only Additive Manufacturing (AM), but also traditional manufacturing capabilities in the field and at Army production facilities. The Tank-Armaments and automotive Command (TACOM) and the Ground Vehicles Systems Center (GVSC) Materials-AdvM Branch have developed a strategy of five critical path key words oriented on three Lines of Effort (LOE) that enables a disciplined process to deliver final use qualified parts manufactured by the Organic Industrial Base (OIB) as an alternate source of supply that will improve readiness of TACOM’s combat and tactical wheeled fleets. Additionally, an alternate critical path has been developed to provide limited use parts for Battle Damage and Repair (BDAR). Citation: P. Burton, N. Kott, A. Kruz, A. Batjer, “Path to 450 Parts Qualified for Advanced Manufacturing”, In Proceedings of the Ground

Burton, Phil, Kott, N. Joe, Kruz, Andrew, Batjer, Ashley

UTILIZING ADDITIVE MANUFACTURING TO ENABLE LOW-COST, RAPID FORMING OF HIGH TEMPERATURE LIGHTWEIGHT GROUND VEHICLE STRUCTURES

2024-01-3926

11/15/2024

ABSTRACT Barriers to the introduction of composite materials for ground vehicle applications include material property selection and cost effective material processing. Advancements in processing of thermoplastic composites for use in applications for semi structural and structural applications have created opportunities in “Out of Autoclave” processing utilizing preconsolidated unidirectional reinforced tapes. Traditional tooling for the bending formation of high temperature reinforced structural thermoplastic laminates typically involves matched metal tooling consisting of steel or aluminum and are costly and heavy. In this research, a comparative analysis was performed to evaluate the use of a large scale 3D printed forming tool in comparison to a traditional metallic mold. Material processing considerations included the development of a technique for localized laminate heating to achieve optimized energy input in the forming process. Considerations in tooling development included

Erb, David, Dwyer, Benjamin, Roy, Jonathan, Yori, William, Lopez-Anido, Roberto A., Smail, Andrew, Hart, Robert

Robotic GMA-P DED AM Build Technology for Aluminum Vehicle Structures

2024-01-3927

11/15/2024

ABSTRACT Gas metal arc pulse directed energy deposition (GMA-P DED) offers large-scale additive manufacturing (AM) capabilities and lower cost systems compared to laser or electron beam DED. These advantages position GMA-DED as a promising manufacturing process for widespread industrial adoption. To enable this “digital” manufacturing of a component from a computer-aided design (CAD) file, a computer-aided manufacturing (CAM) solver is necessary to generate build plans and utilize welding parameter sets based on feature and application requirements. Scalable and robot-agnostic computer-aided robotics (CAR) software is therefore essential to provide automated toolpath generation. This work establishes the use of Autodesk PowerMill Ultimate software as a CAM/CAR solution for arc-based DED processes across robot manufacturers. Preferred aluminum GMA-P DED welding parameters were developed for single-pass wide “walls” and multi-pass wide “blocks” that can be configured to build a wide

Canaday, J., Harwig, D.D., Carney, M.

METALLIC COMPOSITE MATERIALS FOR AFFORDABLE & RELIABLE THERMAL MANAGEMENT OF HIGH POWER DEVICES

2024-01-3178

11/15/2024

ABSTRACT Lower cost aluminum silicon carbide (Al-SiC) metal matrix composite (MMC) produced by stir-casting is emerging as an important material in cost effectively improving the reliability of high power electronic devices; e.g. electronic (IGBT) baseplates, thermal spreaders & stiffeners for flip-chip microelectronics, and heat slugs or MCPCB base layers for high brightness LEDs. This paper will review the properties and competitive cost of these new Al-SiC materials as well as the ability to tailor the coefficient of thermal expansion (CTE) of the Al-SiC to minimize thermal fatigue on solder joints and reduce component distortion. The impact on the final component cost through the use of conventional forming techniques such as (a) rolling sheet followed by stamping, and, (b) die casting, will be described, as will be the opportunity of eliminating a thermal interface material (TIM) layer by integrating the thermal spreader with the heat sink for high power microelectronic packages

Drake, Allen, Schuster, David, Skibo, Michael

GVSETS 2020 PAPER: FATIGUE-FOCUSED WELD ASSEMBLY OPTIMIZATION

2024-01-3834

11/15/2024

ABSTRACT This work presents the development and application of an optimization algorithm for simultaneously improving the fatigue life and minimizing a representative manufacturing cost when assembling a ground combat vehicle. High stress in the occupied space of the weld decreases the fatigue life of the structure; therefore, by minimizing the weld’s exposure to high stresses, the structure’s life can be improved. The new capability for simultaneously improving the fatigue life of a welded structure while reducing a manufacturing cost is demonstrated by considering the welding of a representative panel of a v-hull. Selections are made for the weld placement, the weld type, and the type of filler material, in order to minimize exposure to high stresses and therefore maximize fatigue life. In addition to the stress evaluation, the optimization considers manufacturing cost as another objective in parallel. The final evaluation provides an assembly design to increase the fatigue life and

Mayhood, Carly, Vlahopoulos, Nickolas

STRUCTURAL REPAIR FOR STRYKER HH STEEL BODY PANELS USING COLD SPRAY

2024-01-3814

11/15/2024

ABSTRACT Corrosion damage to military ground vehicles costs the U.S. Army around $1.6B per year. A large part of that cost is related to keeping vehicles like the Stryker at their full fighting capability. Corrosion damage has been a common finding on Stryker vehicles and even light corrosion damage, which often reaches 10% of the body thickness or more, can degrade its armor protection rating and require replacement. Recently, cold spray deposition has been shown to be capable of restoring the full ballistic resistance of corrosion damaged high hard steel armor panels. These repairs can be done on-vehicle in depot facilities, using mobile high-pressure cold spray systems. This repair capability can reduce the number of entire side, roof, and floor panels that need to be cut out and re-welded in, which is the only currently approved repair operation for corrosion damage that exceeds allowable depths. Citation: V.K. Champagne, C.A. Widener, A.T. Nardi, G.D. Ferguson, “Structural Repair

Champagne, Victor K., Widener, Christian A., Nardi, Aaron T., Ferguson, Gehn D.

HIGH MN, HIGH AL STEELS FOR THICK PLATE ARMOR APPLICATIONS

2024-01-3739

11/15/2024

ABSTRACT FeMnAlC alloys exhibit lower density (6.5-7.2 g/cm3) than traditional military steels (7.9 g/cm3) while maintaining similar energy absorption capabilities. Material substitutions in legacy systems must meet existing form/fit/function requirements, limiting opportunities for lightweighting of existing designs. This study examines production and material properties of thick plate with a nominal chemistry of 30% Mn, 9%Al and 1%C, in the wrought condition. Due to the high aluminum and carbon content, there are unique challenges to large scale (45+ ton heat) production versus typical armor steel chemistries. Lab-scale wrought and production material are characterized, comparing microstructure, and mechanical properties. Processing practices including teeming flux and rolling temperature are discussed. The high manganese content of this alloy presents challenges for welding and machining practices, such as limited compatibility of weld wires and substantial work hardening during

Sebeck, Katherine, Toppler, Ian, Rogers, Matt, Limmer, Krista, Cheeseman, Bryan, Howell, Ryan, Herman, William

Fuel Efficient Demonstrator (FED) Bravo, Technology in Motion

2024-01-3533

11/15/2024

ABSTRACT Increased fuel efficiency in military vehicles today results in two primary positive impacts to operational conditions. The first is the reduction in cost; both as a result of reduced fuel consumed and also in the costs saved due to the reduction in logistics required to transport fuel to the Warfighter in the field. The second and more important positive impact is the reduced risk of casualties to the Warfighter by reducing the frequency of fuel related logistical support required in the field. This paper first provides an overview of the development of the Fuel Efficient Demonstrator (FED) Bravo vehicle from initial conceptual efforts through to final operational shake-out and performance testing. A review the development process from CAD modeling through to fabrication and testing will be discussed. This discussion will also focus on the unique methods and ideas used to address the particular challenges encountered in developing a demonstrator vehicle. The paper concludes

Card, Brandon, Todd, Steven, Buchholz, William

Investigation of Hot Cracking Phenomena in Light-Weight Armor Steel Based on the FeMnAl-C Alloy System

2024-01-3738

11/15/2024

ABSTRACT The US Army TARDEC has been researching an alternative to current armor steel that is both tough, and light-weight. The studied alloy is based on the Fe-Mn-Al-C system. This study was conducted to investigate and quantify this alloy’s susceptibility to hot cracking phenomena related to casting and welding. Very little research has been done on general weldability of this alloy system, so the results of these tests will be compared to other high Mn steels, and alloys that have undergone cast pin tear testing. Testing will be conducted utilizing button melting tests, autogenous spot welds, and cast pin tear testing. The cast pin tear testing was conducted to measure this alloys susceptibility to weld solidification cracking. The spot welds were used to quantify the susceptibility of the weld heat affected zone (HAZ) to liquation cracking, as well as to observe the solidification structure of the fusion zone. The testing results showed that the FeMnAl system in its current form

Evans, William, Ramirez, Antonio J., Sebeck, Katherine

DEVELOPMENT OF A SCALABLE THERMOMECHANICAL PROCESS (TMP) FOR THICK BAINITIC ARMOR STEEL

2024-01-3745

11/15/2024

ABSTRACT A bainite phase-based alloy and associated thermomechanical process were developed to produce (2.5 to over 5 cm) thick armor-grade steel with uniform through-thickness high hardness and strength. The alloy composition and the final-critical (austenite to bainite) isothermal transformation step were specifically designed to utilize a simple and versatile air-cool/quench method to keep a low upfront capital cost and to provide the ability to continuously control the cooling rate in real time, in order to produce maximum volume fraction of bainite phase, and promote uniformly distributed strength and hardness. Final thickness of 1.9 cm and 5.7 cm steel plates were fabricated for characterization, testing and evaluation and found to possess uniform through-thickness hardness between 53 to 55 HRC and dynamic compressive strength of up to 2 GPa

Chu, Henry S., Lillo, Thomas M., Anderson, Jeffrey A., Zagula, Thomas A.

ADDITIVE MANUFACTURING REPAIR METHODS FOR METALLIC COMPONENTS

2024-01-3742

11/15/2024

ABSTRACT As metallic parts are used, wear, fracture, galling, warpage, and other forms of obsolescence occur. When these issues progress beyond a predefined level, the parts are either replaced or repaired. Replacement leads to undesirable logistics requirements, especially for those parts requiring difficult-to-source, expensive and/or long-lead-time materials. Repair options are often limited due to strict performance requirements of the parts or concern over the quality of the repair. Two relatively new additive manufacturing (AM) process options exist to complete repairs, including repairs required in theater. Hybrid repair via metal AM followed by precision machining within a single setup offers unique repair options not previously available. Though somewhat limited with respect to the number of alloys currently tested, hybrid AM via directed energy deposition (i.e., powder sprayed into a laser-heated liquid metal pool) offers the possibility to quickly, economically and

Sabo, Kenneth M., Golesich, Brock T., Tims, Michael L.

FORMING AND WELDING INNOVATIONS FOR ARMOR STEELS

2024-01-3740

11/15/2024

ABSTRACT This paper reviews research that has been conducted to develop inductively assisted localized hot forming bending technologies, and to use standardized welding tests to assess the practicality and potential benefits of adopting stainless based consumables to weld both existing and evolving armor alloys. For the titanium alloy Ti6Al4V it was determined that warming the plate to circa 600°F would improve the materials ductility (as measured by reduction of area) from ~18 to 40% without exposing the material to a temperature at which atmospheric contamination would be significantly deleterious. For the commercial alloy BB and class 1 armor alloy it was found that there was little effect on the charpy impact toughness and the proof strength as a result of processing at 900 °F with either air cool or water quench and there was an added benefit of lower residual stresses in the finished bends compared to cold formed bends. Heating “alloy BB” to 1600 °F followed by water quench

Lawmon, John, Alexandrov, Boian, Duffey., Matthew, Ngan., Tiffany

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