Search NASA⌕ Search

SEARCH · Search NASA

Results for “Additives”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15

Additively manufacturing high-temperature aluminum alloy for automotive engine pistons

The purpose of the project was to evaluate DuAlumin-3D, an ORNL designed Al alloy, for additive manufacturing of high-performance automotive components. The project consisted of additively manufacturing a cylindrical block of representative material which was then heat treated before machining into test coupons. Testing included tensile tests as a function of temperature, high-cycle fatigue testing as a function of temperature, density and elastic modulus measurements, and thermophysical property measurements. Fractography was also performed on failed high-cycle fatigue specimens. The results were compared against benchmark AM Al alloys and current high-performance conventionally manufactured alloys. Overall, the DuAlumin-3D material outperformed the incumbent materials in mechanical properties, especially at elevated temperatures, while maintaining broadly similar thermophysical properties. The results of this study support further maturation of the material for additive manufacturing of high-performance automotive components.

36 MATERIALS SCIENCE↗

Determination of the Solid-State Resistance-Weldability of Additively Manufactured 304L Stainless Steel

• A scoping study was undertaken at Savannah River National Laboratory (SRNL) to determine the solidstate resistance-weldability of additively manufactured 304L stainless steel. • Additive manufacturing of pressure-containing boundaries is of interest to numerous industries. • The approach investigated in this study was a low energy, solid state spot weld (pinch weld). • This general approach has been routinely used for conventionally prepared tubing and is now being expanded to additively manufactured components. • This work aimed to understand the impact of AM on the bond quality and weld geometry of pinch welds.

Rogers, Jeremy K. [Savannah River National Laborat↗

Additive Manufacturing Evaporative Casting

Traditional lost foam casting has been around for decades. The process uses foam forms blown by an injection molding like process or CNC milled into the desired shape, then pouring molten metal over the foam pattern to create a metallic object. Additive Manufacturing Evaporative Casting (AMEC) is a new process that eliminates foam forms by using additive manufacturing to 3D print the desired cast geometry. This not only saves time and money but allows for more advanced and complex designs that can’t be achieved by carving foam. Additionally, AMEC doesn’t require molds and tooling like other casting and foundry options. Because the AMEC process is new, extensive testing is needed to develop a better understanding of the process to minimize defects, quantify material properties, and start computer modeling for the process. This CRADA (collaborative research and development agreement) between ORNL and Skuld seeks to improve the process, develop a computational model, characterize material properties, and explore new applications.

36 MATERIALS SCIENCE↗

The Structure-Properties Relationship of Alternative Bismaleimide Variants for Candidacy for Additive Manufacturing

Modernizing the manufacturing of high-performance polymer foams such as amino-poly(oxadiazole) bismaleimide (APO-BMI), a bismaleimide resin with superior thermal and compressive strength that incorporates additive manufacturing (AM) techniques, is crucial for its applications, but the parameters for AM can be challenging based on the physical properties of the associated monomer. For our applications, selective laser sintering (SLS) is typically used. SLS is a 3D printing technique that allows for complex shapes and geometries without structural supports while also providing high resolution material. However, printing thermosets like APO-BMI with SLS is challenging due to the complex melting and curing considerations required when selecting parameters. Additionally, the temperature difference between melting and curing of APO-BMI is over a hundred º C, which makes selecting a sintering window especially difficult. This work explores structural modifications of APO-BMI that may be more amenable for selective laser sintering. The effects of how different structural changes such as substitution pattern, heteroatom identity in the bridge, and bridge length affect the thermal properties of the material were also compared. All APO variants were found to have a smaller temperature window between the melting and curing peaks based on differential scanning calorimetry (DSC) which is advantageous for SLS. Small structural changes significantly altered the melting and curing properties of APO. Additionally, DSC revealed significant polymorphisms in APO-BMI and other APO variants which could be attributed to differences in thermal history and would need to be considered when adapting for SLS.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Designing carbon wetting layers with inorganic salts as additives for enhanced adhesion and molten sodium wettability in electrochemical application

ß” alumina solid-state electrolyte (BASE) is considered one of the most promising materials for sodium batteries due to its high ionic conductivity and exceptional stability with molten sodium. However, at lower operating temperatures, the poor physical contact at the liquid-solid interface between molten sodium and BASE results in high interfacial resistance. In this study, we explore the optimization of carbon wetting layers with various salt additives to enhance adhesion and improve molten sodium wettability. Using a spray-coating method, carbon layers incorporating sodium hexametaphosphate (Na6(PO3)6, SHMP) as an additive demonstrate superior adhesion, mechanical stability, and enhanced wettability with molten sodium. Scanning Electron Microscopy (SEM) analysis reveals that SHMP preserves the porous carbon network required for efficient sodium transport while minimizing structural defects such as cracks and voids. Electrochemical testing using Na symmetric cells confirms that SHMP-modified layers significantly reduce interfacial resistance and overpotential, outperforming No salts counterparts. These findings highlight that the strategic incorporation of suitable additives, such as SHMP, in the design of microscale carbon layers could significantly enhance the performance of molten sodium batteries at lower operating temperatures.

Han, Henry H.↗

An Additively Manufactured Fe-3Si Stator for a High-Performance Electrical Motor

Additive manufacturing (AM) has the potential to produce novel high-performance electrical machines, enabling the direct printing of complex shapes and the simultaneous processing of multiple feedstocks in a single build. We examined the properties and functional performance of Fe-3 wt.% Si materials that were printed via selective laser melting, machined down to thin laminates, and stacked to form a stator core of a prototype brushless permanent-magnet electrical motor. Big Area Additive Manufacturing of Nd2Fe14B (NdFeB)–polyphenylene sulfide (PPS) bonded magnets was performed, with them then being magnetized and used for the rotor. The magnetic, mechanical, and electrical properties of the as-printed and various heat-treated thin laminates and the back electromotive force (EMF) of the electrical motors at different rotational speeds were measured. The thin laminates exhibit a maximum relative permeability of 7494 at an applied field of 0.8 Oe and a core loss of about 20 W/lb at 60 Hz with the maximum induction of 15 kg. In addition to the demonstration of AM printing, motor assembly, and complete characterization of printed Fe-3 wt.% Si, this report highlights the areas of improvement needed in printing technologies to achieve AM built electrical motors and the need for isotropic microstructure refinements to make the laminates appropriate for high-mechanical-strength and low-loss rotational electrical devices.

36 MATERIALS SCIENCE↗

Data for "Integrated ab initio modelling of atomic order and magnetic anisotropy for rare-earth-free magnet design: effects of alloying additions in L1 0 FeNi."

We describe an integrated modelling approach to accelerate the search for novel, single-phase, multicomponent materials with high magnetocrystalline anisotropy (MCA). For a given system we predict the nature of atomic ordering, its dependence on the magnetic state, and then proceed to describe the consequent MCA, magnetisation, and magnetic critical temperature (Curie temperature). Crucially, within our modelling framework, the same ab initio description of a material’s electronic structure determines all aspects. We demonstrate this holistic method by studying the effects of alloying additions in FeNi, examining systems with the general stoichiometries Fe 4 Ni 3 X and Fe 3 Ni 4 X, for additives including X = Pt, Pd, Al, and Co. The atomic ordering behaviour predicted on adding these elements, fundamental for determining a material’s MCA, is rich and varied. Equiatomic FeNi has been reported to require ferromagnetic order to establish the tetragonal L1 0 order suited for significant MCA. Our results show that when alloying additions are included in this material, annealing in an applied magnetic field and/or below a material’s Curie temperature may also promote tetragonal order, along with an appreciable effect on the predicted hard magnetic properties.

36 MATERIALS SCIENCE↗

Activation energies for addition of O/3P/ to simple olefins.

Description of relative rate measurements for the addition of O(3P) to C2H4, C2F4, C3H6, and C4H8-1 in liquid argon at 87.5 K. The data strongly indicate that the activation energies for the addition of O(3P) to the double bonds of propylene and butene-1 are identical, probably to within 0.1 kcal/mole. It is very doubtful that differences in pre-exponential factors or other factors such as solvent effects, could invalidate this conclusion. A similar argument holds for the C2H4 and C2F4 reactions. Furthermore, the experiments suggest that the activation energy for addition of O(3P) to the double bond of butene-1 is about 0.1 kcal/mole.

Demore, W. B.↗

An investigation on the effect of second-order additional thickness distributions to the upper surface of an NACA 64 sub 1-212 airfoil

An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of an NACA 64 sub 1 - 212 airfoil. Additional thickness distributions employed were in the form of two second-order polynomial arcs which have a specified thickness at a given chordwise location. The forward arc disappears at the airfoil leading edge, the aft arc disappears at the airfoil trailing edge. At the juncture of the two arcs, x = x, continuity of slope is maintained. The effect of varying the maximum additional thickness and its chordwise location on airfoil lift coefficient, pitching moment, and pressure distribution was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic NACA 64 sub 1 - 212 airfoil, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.

Hague, D. S.↗

An investigation on the effect of second-order additional thickness distributions to the upper surface of an NACA 64-206 airfoil

An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of an NACA 64-206 airfoil. Additional thickness distributions employed were in the form of two second-order polynomial arcs which have a specified thickness at a given chordwise location. The forward arc disappears at the airfoil leading edge, the aft arc disappears at the airfoil trailing edge. At the juncture of the two arcs, x = x, continuity of slope is maintained. The effect of varying the maximum additional thickness and its chordwise location on airfoil lift coefficient, pitching moment, and pressure distribution was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic NACA 64-206 airfoil, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.

Merz, A. W.↗

Theoretical effect of modifications to the upper surface of two NACA airfoils using smooth polynomial additional thickness distributions which emphasize leading edge profile and which vary quadratically at the trailing edge

An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of the NACA 64-206 and 64 sub 1 - 212 airfoils. The additional thickness distribution had the form of a continuous mathematical function which disappears at both the leading edge and the trailing edge. The function behaves as a polynomial of order epsilon sub 1 at the leading edge, and a polynomial of order epsilon sub 2 at the trailing edge. Epsilon sub 2 is a constant and epsilon sub 1 is varied over a range of practical interest. The magnitude of the additional thickness, y, is a second input parameter, and the effect of varying epsilon sub 1 and y on the aerodynamic performance of the airfoil was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic airfoils, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.

Merz, A. W.↗

Effect of additions of coarse grains and fibers on the densification of a sinterable SiC

This note reports the effects on densification of independent additions of coarse equiaxed SiC grains and fibrous SiC that were mixed with fine beta-SiC to develop a duplex microstructure with improved toughness. The fine-matrix SiC did not contain excess boron and carbon. The equiaxed CVD beta-SiC was introduced in the fine beta-SiC matrix material in amounts of 5 and 10 wt%. Results indicate that the CVD beta-SiC, which is quite coarse, exhibits little indication of sinterability. The effect of these coarse-grained and fibrous additions on the sinterability of fine beta-SiC may result from a geometric type of interaction. This interpretation is reinforced by X-ray diffraction of the powders and sintered pellets via monochromatic CuK-alpha radiation; the diffraction patterns of the sintered composite structures are virtually a combination of those of the components. The addition of nonsinterable SiC to the sinterable material slightly reduces sinterability, the larger particles interacting geometrically with the fine matrix material to prevent complete densification.

Abe, H.↗

Effect of a chromium-containing fuel additive on hot corrosion

Four superalloys were tested at 900 C in high velocity combustion gases containing synthetic sea salt and, in some cases, a chromium containing fuel additive. While the additive reduced hot corrosion of the alloys over the 100 hour test period, the attack was not eliminated nor was the mode of attack changed. Reduction of the number of thermal cycles had as large a beneficial effect as the Cr additive. Intermittent washing during testing had either small beneficial or adverse effects depending on the alloy.

Lowell, C. E.↗

Analysis of economics of a TV broadcasting satellite for additional nationwide TV programs

The influence of a TV broadcasting satellite, transmitting four additional TV networks was analyzed. It is assumed that the cost of the satellite systems will be financed by the cable TV system operators. The additional TV programs increase income by attracting additional subscribers. Two economic models were established: (1) each local network is regarded as an independent economic unit with individual fees (cost price model) and (2) all networks are part of one public cable TV company with uniform fees (uniform price model). Assumptions are made for penetration as a function of subscription rates. Main results of the study are: the installation of a TV broadcasting satellite improves the economics of CTV-networks in both models; the overall coverage achievable by the uniform price model is significantly higher than that achievable by the cost price model.

Becker, D.↗

Effectiveness of various organometallics as antiwear additives in mineral oil

Sliding friction experiments were conducted with 1045 steel contacting 302 stainless steel and lubricated with various organometallics in mineral oil. Auger emission spectroscopy was used to determine the element present in the wear contact zone. The results indicate that there are organometallics which are as effective an antiwear additives as the commonly used zinc dialkyl dithiophosphate. These include dimethyl cadmium, triphenyl lead thiomethoxide, and triphenyl tin chloride. The additives were examined in concentrations to 1 weight percent. With dimethyl cadmium at concentrations of 0.5 weight percent and above, cadmium was detected in the contact zone. Coincident with the detection of cadmium, a marked decrease in the friction coefficient was observed. All additives examined reduced friction, but only the aforementioned reduced wear to a level comparable to that observed with zinc dialkyl dithiophosphate.

Buckley, D. H.↗

Aerodynamic characteristics of an NASA supercritical-wing research airplane model with and without fuselage area-rule additions at Mach 0.25 to 1.00

Transonic pressure tunnel tests at Mach numbers from 0.25 to 1.00 were performed to determine the effects of area-rule additions to the sides of the fuselage on the aerodynamic characteristics of a 0.087 scale model of an NASA supercritical-wing research airplane. Presented are the longitudinal aerodynamic force and moment characteristics for horizontal-tail deflection angles of -2.5 deg and -5 deg with the side fuselage area-rule additions on and off the model. The effects of the side fuselage area-rule additions on selected wing and fuselage pressure distributions at near-cruise conditions are also presented.

Bartlett, D. W.↗

Effects of oxide additions and temperature on sinterability of milled silicon nitride

Specimens of milled alpha-Si3N4 with 0 to 5.07 equivalent percent of oxide additions were pressureless sintered at 1650 to 1820 C for 4 hours in nitrogen while covered with powdered Si3N4 + SiO2. Densities of less than or equal to 97.5 percent resulted with approximately 2.5 equivalent percent of MgO, CeO2, Y2O3, and three mixtures involving these oxides. Densities of greater than or equal to 94 percent were obtained with approximately 0.62 equivalent percent of the same additives. At most temperatures, best sinterability (density maxima) was obtained with 1.2 to 2.5 equivalent percent additive.

Arias, A.↗

Development of new addition-type composite resins

The most promising of a number of new addition type polyimides and polyaromatic melamine (NCNS) resins for use in high performance composite materials. Three different cure temperature ranges were of interest: 530-560 K (500-550 F), 475-530 K (400-500 F), and 450 K (350 F). Examined were a wide variety of polyimide precursors terminated with 5 norbornene groups and addition polymerized at 560 K similar to PMR-15 and LARC-160 polyimides. In addition, a number of lower curing cinnamal end capped polyimides and a bismaleimide were investigated but were not found promising. A group of NCNS resins were investigated and some were found to be superior to current epoxy resins in moisture resistance, oxidative aging and flame and smoke properties.

Kray, R. J.↗