Instructions for Build, Assembly, and Test (IBAT) refers to the process used whenever any operation is conducted on hardware, including tests, assembly, and maintenance. Currently, the generation of IBAT documents is time-intensive, as users must manually reference and transfer information from engineering diagrams and parts lists into IBAT instructions. With advances in machine learning and computer vision, however, it is possible to have an artificial intelligence (AI) model perform the partial filling of the IBAT template, freeing up engineer time for more highly skilled tasks. AiBAT is a novel system for assisting users in authoring IBATs. It works by first analyzing assembly drawing documents, extracting information and parsing it, and then filling in IBAT templates with the extracted information. Such assisted authoring has potential to save time and reduce cost. This paper presents an overview of the AiBAT system, including promising preliminary results and discussion on future work.

Bulk Metallic Glasses (BMGs) are becoming prevalent as specialty components in aerospace, energy, and medical technologies, and hold long-term potential as consumer good components. When manufacturing BMG components by solidification and thermoplastic forming, however, even small deviations from optimal processing conditions can alter the structural glass state, promote crystallization, and introduce geometric flaws. Established techniques to evaluate the integrity of BMG components are often expensive, time-consuming, and destructive in nature. In this study, we employ Resonance Ultrasound Spectroscopy (RUS) as an inexpensive, fast, and non-destructive alternative to accurately measure the elastic properties of BMG components and thus estimate their fictive temperature. Further, RUS can detect crystallinity and geometric flaws. These capabilities are demonstrated even for complex component geometries, based on a BMG planet gear here.

Bulk metallic glasses (BMGs) are multi-element metal alloys with attractive properties for spacecraft applications. With recent advances in the BMG supply chain and commercialization, understanding the effects of thermal history associated with the manufacturing, integration, and service on performance of BMG components is critical for infusion. In this study, a Cu43Zr43Al7Be7 (at. %) BMG-forming composition, an alloy developed for gears for extreme-environment applications, was investigated. The thermal properties and structural glassy states resulting from different thermal treatments were studied with differential scanning calorimetry, microhardness, and four-point bending tests. It is shown that the thermal history and resulting structural states have a pronounced effect on some mechanical properties, highlighting the necessity of qualifying parts in different glassy states for their intended practical applications.

Additive manufacturing has ushered in a new paradigm of bottom-up materials-by-design of spatially non-uniform materials. Functionally graded materials have locally tailored compositions to provide optimized global properties and performance. In this letter, we propose an opportunity for the application of graded magnetic materials as lens elements for charged particle optics. A Hiperco50/Hymu80 (FeCo-2 V/Fe-80Ni-5Mo) graded magnetic alloy was successfully additively manufactured via Laser Directed Energy Deposition with spatially varying magnetic properties. The compositional gradient is then applied using computational simulations to demonstrate how a tailored material can enhance the magnetic performance of a critical, image-forming component of a transmission electron microscope.

Producing soft magnetic alloys by additive manufacturing has the potential to overcome cracking and brittle fracture issues associated with conventional thermomechanical processing. Fe-Co alloys exhibit high magnetic saturation but low ductility that makes them difficult to process by commercial methods. Ni-Fe alloys have good ductility and high permeability in comparison to Fe-Co, but they suffer from low magnetic saturation. Functional grading between Fe-Co and Ni-Fe alloys through blown powder directed energy deposition can produce soft magnetic materials that combine and enhance properties beyond the strengths of the individual magnetic materials. This work focuses on the microstructure, crystal structure, and magnetic properties of functionally graded Fe49Co49V2/Ni80Fe16Mo4 coupons. The grading between the two materials is found to refine the microstructure, thereby improving the mechanical hardness without the use of a nonmagnetic element. Postbuild thermal treatments are found to recrystallize the microstructure and increase the grain size, leading to improved magnetic properties. Analysis of crystal structures provides an understanding of the solubility limits and phase equilibria between the BCC (Fe-Co) and FCC (Ni-Fe) structures. Success in functional grading of soft magnets may provide a pathway toward improving energy conversion efficiency through strategic combinations of high saturation and high strength materials.

Resonant ultrasound spectroscopy (RUS) is capable of determining the single crystal elastic constants from polycrystalline specimens with known crystallographic texture. However, the calculated single crystal elastic constants vary with the measured texture, resulting in inconsistent estimates for additively manufactured (AM) specimens with heterogeneous texture regions. In this work, the accuracy of the determined single crystal elastic constants is improved by incorporating the uncertainty of the texture in the determination of single crystal elasticity, and requiring only small quantities of electron backscatter diffraction data (EBSD) to do so. The single crystal elastic constants are determined by Bayesian inference with parallelized sequential Monte Carlo (SMC), enabling an order of magnitude reduction in computational cost. AM specimens of a cobalt-nickel-base superalloy (SB-CoNi-10C) demonstrate that the incorporation of texture variability enables the single crystal elastic constants to converge to the reported literature values within one standard deviation, avoiding any dependence on the initial texture values. The single crystal elastic constants of nickel-base-superalloy Inconel 625 (IN625) and Ti-6Al-4V (Ti64) are determined from AM specimens, using only RUS and EBSD data. The determined single crystal elastic constants of IN625 agree between two different texture conditions (induced by AM raster strategy), as well as with the literature values, within one standard deviation. The single crystal elastic constants determined from three AM Ti64 specimens, printed with different beam powers, agree with the range of literature values within two standard deviations but demonstrate variability between AM specimens, indicating that the frequencies may be susceptible to the effects of secondary phases.

The Space Environment Dynamometer (SED) chamber was designed to conduct research in cryobotics; an area of study that focuses on robotic systems and rotating machinery operating in extreme cold environments including Earth, low Earth orbit, Mars, Moon, asteroids, Solar orbit, planetary orbit, or those encountered during travel among these destinations. The test chamber incorporates a modular dynamometer, consisting of a variety of brakes, torque sensors and motors to be easily interchanged between tests. Each test employs a unique test profile that incorporates different setpoints of applied torques and velocities for a given period or number of revolutions. The modularity of the dynamometer setup allows for any combination of motor, gearbox to be tested. This chamber is one of a kind and resides at the Swamp Works facility within the Granular Mechanics and Regolith Operations laboratory (GMRO) at NASA Kennedy Space Center. Other cold chambers exist, however they are project specific and do not simultaneously output real time torque, temperature and efficiency data. The modularity of this extreme cold environment test chamber, coupled with the custom software and instrumentation, makes it one of a kind. The chamber is capable of stabilizing cryogenic temperatures and pressures to commensurate moon environments. Tests have successfully been conducted on motors and gearboxes for various cryogenic temperature set points, torques, and angular velocities. Relevant internal temperatures of the test article and chamber were recorded using a variety of temperature sensors. The temperature setpoints, on the motors and gearboxes tested, were stabilized by using PID gain scheduling of the PWM signal for the various heaters. The heat removal for the motor was provided by creating a thermally conductive path from a cryohead directly to the test article using copper straps. A variety of strainwave gears (SWGs), also known as Harmonic drives, planetary gear systems and DC motor actuator configurations have been tested in the chamber. The experiments performed were for various projects including Bulk Metallic Glass Gears (BMGG), Volatiles Investigating Polar Exploration Rover (VIPER), In-Situ Resource Utilization Pilot Excavator (IPEX). Various upgrades have been made to the extreme cold environment test chamber for the use of cryobotic research. These upgrades greatly increased the autonomous capabilities of the test set up by providing redundancies in the hardware and software. The redundancies were primarily added to protect the integrity of the cryohead. A new strapping and insulation method was performed to create the thermal conductive path from the actuators to the cryohead. The software was upgraded to include temperature setpoint control, further increasing the autonomous capabilities of the test. This paper goes into detail regarding the upgrades made to the extreme cold environment test chamber, as well as highlights the results from a COLDArm acceptance test.

Future surface missions will require accessing new extreme environments which reach cryogenic temperatures. The Cold Operable Lunar Deployable Arm (COLDArm) system and component technologies can enable future missions in these extreme environments, including lunar night and Ocean Worlds. Here we report on the design, fabrication, and initial testing of the COLDArm system. The project is funded through the Lunar Surface Innovation Initiative (LSII) and managed by the NASA Space Technology Mission Directorate (STMD) Game Changing Development (GCD) program. The COLDArm system is developed with industrial partner, Motiv Space Systems, Inc (Pasadena, CA). The robotic arm leverages a design similar to the Mars Phoenix and Mars InSight robotic arms. The arm is four degrees of freedom (DOF), approximately two meters in length, and has a tip force greater than 40 newtons in the primary workspace. The significant innovation of the robotic arm is the ability to work in cryogenic environments without heaters. Eliminating heaters provides the benefits of reducing system energy needs and removing heat from mechanisms located near volatile sample collection locations. The robotic joints include a planetary gearmotor and strainwave gear which utilize bulk metallic glass (BMG) gears to eliminate the need for heaters. Both the BMG planetary gearmotor and BMG strainwave gear have been successfully demonstrated at cryogenic temperatures. Additionally, the Dual-Axis Controller for Extreme Environments (DACEE) motor controller also eliminates the reliance on a warm electronics box (WEB). The DACEE motor controllers have also been successfully demonstrated at cryogenic temperatures. A Robotic Avionics and Sensor Kit (RASK) is located on the baseplate in a WEB. The RASK leverages the avionics design used on the Ingenuity Mars Helicopter which has been successfully demonstrated on Mars. COLDArm specific functionality has been added, including a 4-k resolution stereo camera pair and a force torque sensor (FTS) interface. Flight software (FSW) was also developed which leverages the Ingenuity FSW utilizing the F prime framework. An end effector was designed in collaboration with Kennedy Space Center (KSC) and Glen Research Center (GRC) to collect geotechnical properties from the lunar regolith. End effector features include a scoop and geotechnical tool geometries to enable measurement of regolith properties such as bearing capacity, angle of repose, shear strength, and pressure-sinkage parameters. The geotechnical scoop tool was designed for Titanium additive manufacturing in collaboration with Marshall Space Flight Center (MSFC) following NASA-STD- 6030. A cryogenic capable FTS is located at the end effector to collect six-axis load information during the ground interactions. This FTS leverages the design from Mars 2020 and has been demonstrated at cryogenic temperatures. After fabrication and integration of the system, check-outs in the lab environment confirmed basic functionality of the system. Advanced functional testing was completed in the Jet Propulsion Laboratory (JPL) Lunar Advanced Robotics (LunAR) Lab, including ground interaction demonstrations with GRC-3b lunar regolith simulant. These ground interactions demonstrations included large surface pressure sinkage, angle of repose, and shear tests.

The sensitivity and sophistication of spacecraft for Earth Science and Planetary Science missions are increasing with each successive mission. Advances in instrumentation, robotics, remote sensing, avionics and controls are allowing un-crewed missions to be incredibly sophisticated. Effective electromagnetic shielding is critical for high fidelity functioning of the spacecraft and onboard instrumentation. Moreover, the geometrical complexity of the shielding arrangement and the constraints of size and shape, make additive manufacturing (AM) a critical, enabling technology for current and future missions. Two AM approaches - directed energy deposition (DED) and laser powder bed fusion (LPBF) - were used to produce Fe-80Ni-5Mo alloy rings and shields. The microstructure and magnetic properties of the materials produced through these processes are reported in this paper. A mechanism relating the microstructure to the soft magnetic performance of the material is proposed. The AM material produced in this work demonstrated the highest reported magnetic permeability and lowest reported coercivity of any additively manufactured soft magnetic material. Two different combinations of bi-metallic shields, Fe-80Ni-5Mo/FeCo-2V and Fe-80Ni-5Mo/Fe-49Ni, were fabricated using the DED process. The creation of these shields as monoliths in general, and for space-related applications in particular, is a novel aspect of this work. These multi-alloy, multi-layer shields showed a nearly 10 dB increase in shielding performance over Fe-80Ni-5Mo single alloy shielding, a significant improvement. For the DED builds, the coercivity decreases and permeability increases (better soft magnetic performance) with increasing build power. With increasing build power in the DED process, the grain size in the printed part increases. The corresponding reduction in the grain boundary area results in fewer obstacles to the movement of magnetic domain walls.

Magnetic shielding in spacecraft is a mission‐critical issue that must be addressed in a timely and effective manner. The high permeability of Fe–Ni–Mo alloys, makes them excellent candidates for magnetic shielding. This article explores a new and innovative approach, enabled by additive manufacturing (AM), to design, build, and test geometrically complex magnetic shields. A Fe–79.7Ni–4.1Mo alloy is additively manufactured using blown powder laser‐directed energy deposition (DED). AM build conditions are explored in the production of magnetic test rings and magnetic shield prototypes. Magnetic hysteresis test data are obtained, allowing for the determination of magnetic permeability, saturation, and coercivity. Detailed microstructural characterization is carried out. Three different prototype shield designs are printed and magnetic shield attenuation data is obtained. The magnetic field attenuation (shield effectiveness) obtained for the AM components is comparable to wrought equivalents. The values reported here for the magnetic permeability are the highest, and that for the magnetic coercivity the lowest, for any blown powder DED‐printed material currently known. The magnetic behavior is discussed with regard to grain size and orientation, as well as grain boundary effects, with all of these attributes contributing to the ultimate performance.

The heat treatment of AlSi10Mg produced by laser powder bed fusion is investigated using various quenchant media and aging conditions. The goal is to utilize conventional and widely-available heat treatment practices that can applied to complex geometry parts. Tensile testing demonstrated the best statistical strength and reduced scatter from an 18% glycol quenching approach with a 10 hour hold at 158 °C, with typical properties validated through testing over a temperature range of -125 °C – 125 °C. An 18% glycol solution provides a significant reduction in statistical variability in yield and ultimate tensile strength versus water and helium quenching, while yielding comparable elongations. An aging time of 8 hours for the 18% glycol quench offers the lowest scatter and maximum performance for the hold times studied. For water quenching and aging, the ideal aging time is between 12 – 20 hours, yielding the best combination of strength coupled with small standard deviations in yield strength, ultimate tensile strength, and elongation. The approach of this work is to yield highly repeatable microstructures and properties with minimal scatter, to reduce the systems-level design conservatism applied through factors of safety and other statistical property reductions.

High-permeability Ni-15 Fe-5 Mo (wt.%) alloy coupons were produced using a directed energy deposition process with varying laser powers and scan speeds. The microstructure of the as-printed alloy is influenced by the printing parameters, and this influence is perceptible even after heat treatment. Electron backscatter diffraction data showed that the grain sizes in all samples were small near the build plate and increase with distance along the build direction. The average grain size of as-printed coupons decreased with increasing scan speed and lower laser power. Preferred orientation along the <110> family of directions was noted when moderate laser powers and scan speeds were utilized. Annealing resulted in a decrease in average grain size with less texturing and more high-angle grain boundaries.

The microstructure and magnetic performance of Fe49Co2V (Hiperco50) manufactured via laser‐directed energy deposition are determined. In the as‐printed form, the material displays a fine, equiaxed microstructure and magnetically “hard” behavior. With a customized post‐process annealing treatment, significant grain growth occurs, resulting in soft magnetic performance comparable to traditionally manufactured materials. An inverse correlation between laser power and post‐anneal grain size is observed, with lower laser powers resulting in samples with larger grain sizes after annealing. Samples printed with lower laser powers also display improvements in soft magnetic performance. This is consistent with the expected relationships between grain size, magnetic permeability, and magnetic coercivity, i.e., as grain size increases, magnetic permeability increases and magnetic coercivity decreases. A prototype magnetic shield for a Hall‐effect thruster is successfully printed. The magnetic performance of the printed and annealed shield is comparable to one that is traditionally manufactured.

Joining of dissimilar metals is required for numerous applications in industries such as chemical, energy and automotive. It is challenging due to differences in melting point, density, and thermal expansion of the metals being joined. Common welding techniques involve limiting melting and solidification to a narrow area leading to high thermal stresses and potentially brittle intermetallic phases. Furthermore, the geometric complexity of these welded joints can be rather limited. Additive Manufacturing (AM) presents new techniques for joining of dissimilar metals. One of the emerging methods is the building of functionally graded parts using Directed Energy Deposition (DED) to spatially vary composition. In this paper, a SS316 L and C300 maraging steel couple were joined by DED and heat treated. 13 discrete composition layers were selected using metallurgical considerations, in order to ensure a smooth transition in properties and microstructure. The mechanical properties of the as-built joints were found to be similar to the SS part and no intermetallic phases were found in the interface.

Cost, mass, volume and schedule limit the extent of science and discovery that can be integrated into many Planetary Science and Astrobiology Missions.Manufacturing, materials and structures are key contributors to these limiting factors, and additive manufacturing (AM) offers integrated solutions to these challenges.Despite worldwide investment in AM, NASA is uniquely positioned to address the singular challenges of Planetary Science and Astrobiology Missions.Specific research and development needs require immediate attention and investment to capitalize on the benefits AM offers. NASA Has a Strong Background in Additive Manufacturing DevelopmentAdditive manufacturing (AM), also known as 3D printing, is a transformative technology that vastly broadens the design space for optimizing materials, parts, and systems for space applications.AM can deliver tremendous performance improvements by enabling more complex and multi-capable material and structure combinations than previously possible.The potential to significant reduce development and fabrication cycle time can provide substantial budget and schedule flexibility for complex missions.A major NASA priority within the science community should be the development of advanced AM solutions targeting future Planetary Science and Astrobiology Missions.NASA has a strong history in AM activities that support the full range of NASA's missions and span all NASA centers.NASA's expertise in AM has benefitted the aerospace industry, other

Compositionally graded cylinders comprising FeCo-2V, a soft magnetic alloy, and 316L stainless steel, were produced by directed energy deposition incorporating two different gradient lengths. Five distinct regions in the microstructure were observed in both the as-printed and annealed gradients. When normalized for the gradient length, the gradients showed similar grain size and microhardness profiles. In tensile tests, the as-printed samples failed in the 316L region with an effective total “composite” strain of 20-30% and overall strength approaching that of wrought 316L. The annealed samples failed in the FeCo-2V region. Neither exhibited failure in the gradient region. Molecular dynamics simulations were used to calculate tensile strength as a function of composition, showing good correlation to experimental trends but not absolute values. This work demonstrates the tunability of site-specific properties using blown powder directed energy deposition to gradually grade from FeCo-2V to 316L stainless steel in a monolithic component.

Over the 2010s technological improvements allowed metal additive manufacturing to graduate from a prototyping tool to a widespread, full-scale manufacturing process. Among the capabilities still under development, however, is the ability to locally tailor alloy composition and properties to fabricate bulk, complex geometry functionally graded materials (FGMs), eliminating the need for dissimilar-metal welds and joints. The challenge of compositional grading involves overcoming chemical, metallurgical, and thermal property differences to achieve a continuous structure between a wide range of selected combinations of alloys. In this review, examples are discussed of fabricating FGMs joining a variety of combinations of stainless, nickel, titanium and copper alloys, and FGMs joining metals to ceramics and metal-matrix composites. The change in design strategy enabled by practical FGMs may lead to effective use of biomimetic designs that are both much more efficient as well as aesthetically pleasing.

We describe the design and testing of the Cryogenic Flex Cable (CFC) delivered for the Near-Infrared Spectro-Photometer (NISP) instrument [1] for the ESA Euclid mission [2, 3]. The Euclid spacecraft is scheduled for launch in the summer of 2022. It will observe similar to 1/3 of the total sky using a telescope with 1.2m SiC primary mirror, passively cooled to similar to 125K, and containing Visible Imager (VIS) [4] and NISP focal plane instruments, from an orbit at the Earth-Sun L2 lagrange point. At the heart of the NISP instrument is a 4X4 mosaic focal plane of Teledyne H2RG infrared detector arrays held at 100K. The CFC described here are designed to link each detector array to a dedicated packaged cryogenic electronics assembly held at similar to 137K with minimal heat leak to the 100K stage and to withstand handling and launch vibrations. Prototype CFCs were developed and tested by Teledyne. The final 7-layer CFC flexible printed circuit boards and Airborn nanoconnectors were provided by Teledyne and assembled for flight at the Jet Propulsion Lab (JPL). Flight qualification CFC were made and subjected to thermal conductance, thermal emissivity, thermal cycle, survivability to bend, vibration and normal mode testing at JPL. The flight CFC were subject to bake out and thermal cycle at JPL and then tested with the flight detectors and electronics at Goddard Space Flight Centers Detector Characterization Lab. The results of the qualification tests as well as the measured characteristics of the 41 manufactured CFC are summarized.

This study focuses on the formation of the σ phase in three functionally graded material (FGM) systems made by additive manufacturing (AM): stainless steel 420 (SS420) to V to Ti-6Al-4V, Ti-6Al-4V to V to stainless steel 304L (SS304L), and SS420 to V. Directly joining Ti-6Al-4V and stainless steel may result in the formation of brittle Fe-Ti intermetallics. This study investigates the potential use of V as an intermediate element between terminal alloys of Ti-6Al-4V and stainless steel. Experimental analysis of the elemental and phase composition revealed that different amounts of σ phase were present in the three FGM systems at locations with similar elemental compositions. Computational studies were performed to simulate the thermal history, phase transformation kinetics, and σ phase growth within these FGMs. The computations suggested that, at the conditions studied, the σ phase should nucleate faster and grow to a larger volume fraction in the SS420-V alloy than the SS304L-V alloy, contrasting with experimental observations. Instead, experimental analysis confirmed that the disparate growth of σ phase in the FGMs was due differences in cracking during fabrication, resulting in different amounts of time spent at the elevated temperatures conducive to σ phase growth in each of the samples.

Interest in additive manufacturing (AM) has expanded dramatically in recent years due to the numerous advantages that this process provides over traditional manufacturing [1]. Although the majority of recent work in AM has been focused on three-dimensional printing of polymers, AM techniques for fabricating metal alloys have been available for more than a decade [2, 3]. Direct Energy Deposition (DED) and in particular, Wire and Arc Additive Manufacturing (WAAM) attracts great interest due to its high deposition rate, environmental friendliness, and cost-competitiveness [4-8]. In particular, WAAM becomes a promising alternative to conventional subtractive methods for fabricating large aerospace alloy components that feature high buy-to-fly ratio [9, 10].