Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Bimetallic”

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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Organometallic Synthesis of Bimetallic Cobalt‐Rhodium Nanoparticles in Supported Ionic Liquid Phases (Co x Rh 100− x @SILP) as Catalysts for the Selective Hydrogenation of Multifunctional Aromatic Substrates

Abstract The synthesis, characterization, and catalytic properties of bimetallic cobalt‐rhodium nanoparticles of defined Co:Rh ratios immobilized in an imidazolium‐based supported ionic liquid phase (Co x Rh 100− x @SILP) are described. Following an organometallic approach, precise control of the Co:Rh ratios is accomplished. Electron microscopy and X‐ray absorption spectroscopy confirm the formation of small, well‐dispersed, and homogeneously alloyed zero‐valent bimetallic nanoparticles in all investigated materials. Benzylideneacetone and various bicyclic heteroaromatics are used as chemical probes to investigate the hydrogenation performances of the Co x Rh 100− x @SILP materials. The Co:Rh ratio of the nanoparticles is found to have a critical influence on observed activity and selectivity, with clear synergistic effects arising from the combination of the noble metal and its 3d congener. In particular, the ability of Co x Rh 100− x @SILP catalysts to hydrogenate 6‐membered aromatic rings is found to experience a remarkable sharp switch in a narrow composition range between Co 25 Rh 75 (full ring hydrogenation) and Co 30 Rh 70 (no ring hydrogenation).

Rengshausen, Simon↗
DOE OSTI2020

Manufacturing of magnesium/aluminum bimetallic ring components by friction stir assisted simultaneous forging and solid-state joining

Here, a bimetallic ring component is forged by a friction stir assisted forging (FS-forging). A cylindrical bimetallic blank, magnesium AZ31 cylinder (Mg core) tightly fitted inside an aluminum 6061-T6 tube (Al skin), is used. In the FS-forging, the frictional heat and stirring of rotating tool forge the blank into a desired shape, while simultaneously generate a solid-state joint between the Mg core and the Al skin, without additional external heating, as confirmed by the microstructural analysis and mechanical tests. The microstructural analysis also shows that the characteristics of the solid-state joint can be different depending on the process parameters.

42 ENGINEERING↗
DOE OSTI2025

Stepwise impregnation of bimetallic catalysts for carbon nanotube synthesis

Supported bimetallic catalysts are widely used for carbon nanotube (CNT) synthesis, yet the effects of impregnation procedure remain underexplored. Here, we investigated how the sequence of metal impregnation affects CNT synthesis. We prepared cobalt-molybdenum (Co-Mo) bimetallic catalysts on alumina supports via co- and stepwise impregnation, then compared their CNT synthesis performance under identical conditions. Stepwise-impregnated catalysts exhibited higher carbon yields than those prepared by co-impregnation. Notably, impregnating Mo after Co achieved the highest yield despite the lowest BET surface area. Synchrotron X-ray diffraction and visible/UV-Raman spectroscopy revealed that only this catalyst contained Al 2 (MoO 4 ) 3 with a MoO 4 structure. X-ray photoelectron spectroscopy clarified the surface chemistry: the catalyst with the highest CNT productivity exposed Mo entirely as Mo 6+ in Al 2 (MoO 4 ) 3 and CoMoO 4 , whereas the others contained both Mo 4+ and Mo 6+ . The MoO x species like Al 2 (MoO 4 ) 3 is known to suppress Co sintering during CNT synthesis, delaying catalyst deactivation and enhancing the carbon yield. Moreover, an inverse relationship was observed between carbon yield and the CoMoO 4 content. This is attributed to the consumption of catalytically active Co during CoMoO 4 formation, which reduces active sites for CNT growth. ICP-OES further confirmed higher Co and Mo loadings for stepwise catalysts, contributing to superior catalyst performance. The extent of CoMoO 4 formation strongly depended on the metal introduction sequence. In conclusion, this trend is illustrated by considering the relationship between the point of zero charge of support and the pH of the metal precursor solutions.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Enhanced low temperature performance of bimetallic Pd/Pt/SiO 2 (core)@Zr(shell) diesel oxidation catalysts

Here, in this study, the diesel oxidation performance of degreened (DG) and hydrothermally aged monometallic and bimetallic Pd/Pt/SiO 2 (core)@Zr(shell) catalysts with varying Pd/Pt molar ratios from 3/1–1/3 was evaluated. Pd/Pt(3/1)/SiO 2 @Zr (DG) achieved 50% and 90% conversion of CO at 166 °C (T 50 ), 169 °C (T 90 ) and total hydrocarbons (THCs) at 198 °C (T 50 ), 244 °C (T 90 ). Decreasing the Pd/Pt molar ratio led to a decrease in the T 50,90 ’s, with Pd/Pt(1/3)/SiO 2 @Zr (DG) achieving T 50,90 ’s at 153, 156 °C for CO and 171, 200 °C for THCs, respectively. Moreover, Pd/Pt(1/3)/SiO 2 @Zr showed enhanced hydrothermal stability. XRD and TEM showed that in the hydrothermally aged bimetallic catalysts, the fraction of Pd present as a Pt-Pd metallic alloy increased with Pt content. The enhanced low temperature performance of Pd/Pt(1/3)/SiO 2 @Zr compared to the other studied catalysts was attributed to Pd being primarily present in metallic form, despite being subjected to severe oxidizing conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

H 2 O-assisted O 2 reduction by H 2 on Pt and PtAu bimetallic nanoparticles: Influences of composition and reactant coverages on kinetic regimes, rates, and selectivities

Hydrogen peroxide (H 2 O 2 ) can replace hazardous oxidants in industrial processes but is currently too expensive for many such applications. While direct synthesis of H 2 O 2 (H 2 + O 2 → H 2 O 2 ) may reduce costs in comparison to incumbent technology, current catalysts lack the requisite stability and selectivity. Here, we examine the direct synthesis of H 2 O 2 on bimetallic Pt 1 Au x (0 ≤ x ≤ 230) and Pt catalysts at steady-state in pure water and relate kinetic parameters for H 2 O 2 and H 2 O formation to possible active site structures informed by complementary characterization methods. X-ray photoelectron spectra show significant Pt surface enrichment compared to the bulk composition. Analysis of infrared spectra of mixed monolayers of 12 CO* and 13 CO* indicate that Pt and Au form substitutional surface alloys. The Pt 1 Au x nanoparticles with the greatest mole fractions of Au predominantly expose Pt monomers (i.e., isolated Pt atoms), yet Pt atoms exposed upon all these nanoparticles possess electronic structures distinct from bulk Pt. Despite these differences, rate measurements are consistent with product formation through proton-electron transfer pathways for all Pt 1 Au x catalysts. In situ XAS indicate that Pt remains metallic during H 2 O 2 synthesis. Under the most oxidizing conditions, selectivities toward H 2 O 2 increase strongly with the Au to Pt ratio from 2% for monometallic Pt to 85% for Pt 1 Au 170 . However, selectivities are similar among all catalysts within reducing conditions. Comparisons of apparent activation enthalpies for the formation of H 2 O 2 and H 2 O across these catalysts and the range of conditions suggest that Pt monomers within Au provide the greatest selectivities for H 2 O 2 formation, because these active sites present high barriers for O-O bond rupture. Further, selectivities decrease with increasing ratios of H 2 to O 2 pressures, because Pt atoms aggregate and form oligomers that readily dissociate dioxygen intermediates. The combined use of spectroscopy, kinetics, and concepts employed in reaching these conclusions take inspiration from the legacy of Prof. Michel Boudart, and specifically his elegant methods for interrogating bimetallic catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Interfacial characteristics of P91 steel - Inconel 740H bimetallic structure fabricated using wire-arc additive manufacturing

Although bimetallic structures can offer unique solutions to engineering problems with varying functionality, joining two dissimilar alloys using additive manufacturing involves challenges such as cracking and segregation. In this work, bimetallic structures of Inconel 740H superalloy and P91 steel are processed using wire-arc additive manufacturing (WAAM) for the first time. P91 steel is directly deposited over 740H with a cooling time of 20 minutes in between the two depositions. During microstructure characterization, a large gradient zone with coarse grains spanning for ~2200 μm is observed. Moreover, the microhardness of the gradient zone is the least in comparison with the P91 and 740H deposits. No deleterious phase formation is found; however, intergranular cracks are observed along the gradient zone. In order to deduce the reason for cracking, non-equilibrium solidification simulations are performed for the mixed compositions of P91 and 740H in the gradient zone. Here, the reasons for crack formation in the gradient zone are the sudden change in the volumetric coefficient of thermal expansion due to the formation of MC carbides as well as the development of local strains from the thermal residual stresses. Therefore, altering the deposition sequence and introducing gradient layers with mixed composition between the P91 and 740H deposits will be beneficial in achieving defect-free builds. Through the integration of experiments and simulation, this work gains valuable insights into the processability of dissimilar alloy manufacturing using the WAAM technique.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2025

Characterizing the surface compositions of supported bimetallic PtSn clusters: Effects of cluster-support interactions and surface adsorbates

PtSn bimetallic clusters on TiO2(110) and highly oriented pyrolytic graphite (HOPG) surfaces have been characterized by scanning tunneling microscopy, low energy ion scattering (LEIS), Xray photoelectron spectroscopy, and temperature programmed desorption (TPD); density functional theory (DFT) calculations have also been performed to better understand adsorption of CO and D2 on the PtSn surfaces. On TiO2 at coverages of 2 ML of Pt and 2 ML of Sn, exclusively bimetallic clusters are formed for both orders of deposition because clusters of the first metal completely cover the surface such that all atoms of the second metal are incorporated into the existing clusters. In contrast, on HOPG, the high mobility and weak cluster-support interactions on HOPG result in much larger 2 ML monometallic clusters (~30 Å high) that do not completely cover the surface, and deposition of the second metal produces larger clusters as well as smaller ones. Despite the difference in cluster morphologies for the different orders of deposition and supports, the LEIS experiments demonstrate that in all cases, the PtSn clusters are rich in Sn at the surface, as expected based on the lower surface free energy for Sn compared to Pt. Furthermore, the +0.2 eV shift in the Sn(3d5/2) binding energy observed on all surfaces in the presence of Pt is consistent with PtSn alloy formation. Deposition of 2 ML of Sn on TiO2 produces two-dimensional clusters with oxidation of Sn and reduction of titania at the clustersupport interface, but addition of Pt to the Sn clusters causes Sn to diffuse away from this interface, leaving Sn in the metallic state. TPD experiments on 2 ML Pt/TiO2 with increasing coverages of Sn show that the number of adsorption sites for D2 sharply decreases to nearly zero at 0.5 ML, while CO adsorption decreases to zero only at much higher Sn coverages of 2 ML. DFT studies for Sn modified Pt surfaces and bulk structures demonstrate that for CO adsorption at low Sn coverages (<0.25 ML), the strong Pt-CO interactions induce diffusion of Pt to the cluster surface and the formation of a bulk Pt3Sn alloy, whereas D2 adsorption does not lead to interactions with the Pt surface that are strong enough to induce alloy formation. A single Sn adatom prevents D2 adsorption on four neighboring Pt atoms via site-blocking and the donation of electron density to Pt.

Li, Fangliang↗
DOE OSTI2025

Direct Deoxygenation of Phenol over Fe-Based Bimetallic Surfaces Using On-the-Fly Surrogate Models

We present an accelerated nudged elastic band (NEB) study of phenol direct deoxygenation (DDO) on Fe-based bimetallic surfaces using a recently developed Gaussian process regression (GPR) calculator. Our test calculations demonstrate that the GPR calculator achieves up to 3 times speedup compared to conventional density functional theory calculations while maintaining high accuracy, with energy barrier errors below 0.015 eV. Using GPR-NEB, we systematically examine the DDO mechanism on pure Fe(110) and surfaces modified with Co and Ni in both top and subsurface layers. Our results show that subsurface Co and Ni substitutions preserve favorable thermodynamics and kinetics for both C–O bond cleavage and C–H bond formation, comparable to those on the pure Fe(110) surface. In contrast, top-layer substitutions generally increase the C–O bond cleavage barrier, render the step endothermic, and result in significantly higher reverse reaction rates, making DDO unfavorable on these surfaces. This work demonstrates the effectiveness of GRR-accelerated transition state searches for complex surface reactions and provides insights into rational design of bimetallic catalysts for selective deoxygenation.

Aromatic compounds↗
DOE OSTI2022

Role of Bimetallic Interactions in the Enhancement of Catalytic CO 2 Reduction by a Macrocyclic Cobalt Catalyst

The use of two metal centers in a CO 2 reduction catalyst that work together synergistically, with similar or complementary functions, can potentially lead to a significant reduction in overpotential, enhance catalytic activity and/or selectivity, and/or enable access to cascade strategies where each metal center catalyzes a different step in the conversion of CO 2 to a fuel. Here, the bimetallic reactivity of two metal centers has been identified as the primary route for the reduction of CO 2 to CO promoted by the macrocycle, [Co(HMD)] 2+ (HMD = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene), based on the experimental characterization of all major steps of the proposed catalytic cycle using pulse radiolysis time-resolved IR (PR-TRIR) spectroscopy, corroborated by density functional theory (DFT) calculations and IR spectroelectrochemistry (IR-SEC). A bimetallic intermediate is formed in situ from two singly reduced [Co(HMD)] + species bridged by a CO 2 molecule, and the presence of a coordinating species, e.g., formate anion, appears to assist in the formation of such an intermediate. In this work, it has been demonstrated that this reactivity enables access to elementary steps with lower energy requirements, resulting in overall catalysis being kinetically more facile compared to the mononuclear pathway. A two-step approach that combines chemical reduction followed by PR-TRIR has been successfully used for probing the structure and reactivity of reactive intermediates involved in the advanced stages of a catalytic cycle, which are rarely interrogated using experimental techniques.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Data-Driven Discovery of Bimetallic Nanoparticles Catalysts for the Hydrogenolysis of Polyethylene

Supported platinum nanoparticles are known to convert polyolefins to high-quality liquid hydrocarbons with hydrogen under relatively mild conditions. However, no systematic study has been undertaken using bimetallic catalysts for polyethylene upcycling. Specifically, a total of 98 monometallic and bimetallic combinations (Ag, Cr, Co, Cu, Fe, Ga, In, Mn, Ni, Pd, Pt, Rh, Ru, Zr) on alumina were synthesized utilizing surface organometallic chemistry (SOMC) technique via robotic platform. These were investigated at a small scale (10 mg of catalyst and 50 mg of polyethylene) for their activity for the hydrogenolysis of polyethylene in a high-throughput batch reactor. Combinations of Ni and Co were selected as candidates with high activity toward conversion into paraffin oils. Reaction conditions were optimized with Ni/Co/Al 2 O 3 catalyst at a larger scale (300 mg catalyst and 3 g polyethylene) to obtain a high yield (93.1%) of paraffin wax with desired properties (M n = 380 Da) and low polydispersity (Đ = 1.2). Ni/Co/Al 2 O 3 was compared against Co/Ni/Al 2 O 3 to understand the role of the deposition sequence. When Co is deposited before Ni, a layer of cobalt aluminate is formed upon reduction, stabilizing the deposition of 5 nm metallic Ni particles. When nickel is deposited before Co, particles are larger (average >20 nm) and more oxidized (Ni δ+ in NiAl 2 O 4 ), decreasing the availability of the catalytically active metallic Ni. In conclusion, the difference in electronic environments was also described by DFT calculations, which revealed that smaller 3D clusters of Ni are preferred on CoAl2O4 over the 3D clusters on NiAl 2 O 4 and that these smaller clusters are more reducible, as confirmed experimentally.

Polymer↗
DOE OSTI2020

CO 2 Hydrogenation to Formate and Formic Acid by Bimetallic Palladium–Copper Hydride Clusters

Mass spectrometric analysis of the anionic products of interaction between bimetallic palladium-copper tetrahydride anions, PdCuH 4 – , and carbon dioxide, CO 2 , in a reaction cell shows an efficient generation of the PdCuCO 2 H 4 – intermediate and formate/formic acid complexes. Multiple structures of PdCuH 4 – and PdCuCO 2 H 4 – are identified by a synergy between anion photoelectron spectroscopy and quantum chemical calculations. The higher energy PdCuH 4 – isomer is shown to drive the catalytic hydrogenation of CO 2 , emphasizing the importance of accounting for higher energy isomers for cluster catalytic activity. In conclusion, this study represents the first example of CO 2 hydrogenation by bimetallic hydride clusters.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Transition metal-based bimetallic MOFs and MOF-derived catalysts for electrochemical oxygen evolution reaction

The oxygen evolution reaction (OER) is a critical electrochemical reaction in water splitting and rechargeable metal–air batteries. It plays a pivotal role in achieving high-efficiency clean-energy production and energy storage in these devices. Transition metal-based bimetallic MOFs (TMB MOFs) with two different metal ions possess specific synergistic effects, which could exhibit OER performance and stability superior to those of the corresponding monometallic MOFs for water oxidation. Benefiting from the diversity of chemical composition and structural type, TMB MOFs can also serve as precursors and templates to obtain alloy-particle-decorated carbon materials with high surface area, or metal compounds such as bimetallic sulfides, phosphides, and hydroxides with atomic-level mixing of heterometallic elements. These materials with high-density active sites exhibit much improved catalytic activity in the water oxidation reaction. Furthermore, this article aims to review the recent progress with TMB MOFs and their derivatives in relation to applications as electrocatalysts in OER, including analysis of the mechanism of the OER process with the assistance of DFT calculations and in situ or operando techniques.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Stabilized open metal sites in bimetallic metal–organic framework catalysts for hydrogen production from alcohols

Liquid organic hydrogen carriers such as alcohols and polyols are a high-capacity means of transporting and reversibly storing hydrogen that demands effective catalysts to drive the (de)hydrogenation reactions under mild conditions. We employed a combined theory/experiment approach to develop MOF-74 catalysts for alcohol dehydrogenation and examine the performance of the open metal sites (OMS), which have properties analogous to the active sites in high-performance single-site catalysts and homogeneous catalysts. Methanol dehydrogenation was used as a model reaction system for assessing the performance of five monometallic M-MOF-74 variants (M = Co, Cu, Mg, Mn, Ni). Co-MOF-74 and Ni-MOF-74 give the highest H 2 productivity. However, Ni-MOF-74 is unstable under reaction conditions and forms metallic nickel particles. To improve catalyst activity and stability, bimetallic (NixMg 1-x )-MOF-74 catalysts were developed that stabilize the Ni OMS and promote the dehydrogenation reaction. An optimal composition exists at (Ni 0.32 Mg 0.68 )-MOF-74 that gives the greatest H2 productivity, up to 203 mL gcat -1 min -1 at 300 °C, and maintains 100% selectivity to CO and H 2 between 225–275 °C. The optimized catalyst is also active for the dehydrogenation of other alcohols. DFT calculations reveal that synergistic interactions between the open metal site and the organic linker lead to lower reaction barriers in the MOF catalysts compared to the open metal site alone. This work expands the suite of hydrogen-related reactions catalyzed by MOF-74 which includes recent work on hydroformulation and our earlier reports of aryl-ether hydrogenolysis. Moreover, it highlights the use of bimetallic frameworks as an effective strategy for stabilizing a high density of catalytically active open metal sites.

08 HYDROGEN↗
DOE OSTI2026

Thermodynamics of Bimetallic Joints between Titanium and Tantalum Produced by Laser Powder Bed Fusion

Laser powder bed fusion (LBPF) is currently the most mature metal additive manufacturing (AM) technology. While it does not have the same flexibility as directed energy deposition techniques to produce compositional gradients, LPBF can still be used to generate bimetallic parts by depositing one metal on a build plate made of another. Here, in this study, we print combinations of Ti-6Al-4V with Ta and characterize defects that occur at the interface. We use thermodynamic modeling to explain the formation of keyhole porosity and solidification cracks when Ta is built on a Ti baseplate, and the lack of defects when the materials are reversed. By understanding the mechanisms that lead to defect formation, the methodology demonstrated here can be applied to other material systems to efficiently design bimetallic LPBF processes.

36 MATERIALS SCIENCE↗
NASA NTRS1967

Tube-to-header joint for bimetallic construction

Design advantages of bimetallic construction enables an all-welded bimetallic joint to be made from the accessible header side of the tube-to-header joint. In the two-piece header design the weld joints completely seal the tube-header plate crevice and prevent crevice and stringer corrosion.

Lessmann, G. G.↗
NASA NTRS1974

Bimetallic fluid displacement apparatus

Stirring and heating stored gases and liquids is accomplished by using the deformation of a bimetallic structure which deforms significantly when heated. The deformation is used to effect gradual or impulsive motion of a piston, vane, wire, or diaphram for displacement of the fluid. The heated bimetallic is also employed for heating the stored fluid.

Canning, T. N.↗
NASA NTRS2016

Design, Development and Hotfire Testing of Monolithic Copper and Bimetallic Additively Manufactured Combustion Chambers

NASA and industry partners are working towards fabrication process development to reduce costs and schedules associated with manufacturing liquid rocket engine components with the goal of reducing overall mission costs. One such technique being evaluated is powder-bed fusion or selective laser melting (SLM) otherwise commonly referred to as additive manufacturing. The NASA Low Cost Upper Stage Propulsion (LCUSP) program was designed to develop processes and material characterization for the GRCop-84 copper-alloy commensurate with powder bed additive manufacturing, evaluate bimetallic deposition and complete testing of a full scale combustion chamber. As part of this development, the process has been transferred to industry partners to enable a long-term supply chain of monolithic copper combustion chambers. As a direct spin off of this program, NASA is working with industry partners to further develop the printing process for the GRCop-84 material in addition to the C-18150 (CuCrZr) material. To advance the process further and allow for optimization with multiple materials, NASA is also investigating the feasibility of bimetallic additively manufactured chambers. A 1.2k sized thrust-chamber was designed and developed to compare the printing process of the GRCop-84 and C-18150 SLM materials. A series of similar MCC liners also completed development with an Inconel 625 jacket bonded to the GRcop-84 liner evaluating direct metal deposition (DMD) laser and arc-based techniques. This paper describes the design, development, manufacturing and testing of these combustion chambers and associated lessons learned throughout the design and development process.

Gradl, Paul↗
NASA NTRS2019

Progress in Additively Manufactured Copper-Alloy GRCop-84, GRCop-42, and Bimetallic Combustion Chambers for Liquid Rocket Engines

Additive Manufacturing (AM) has significantly evolved over the last decade for use in the aerospace industry, particularly for liquid rocket engines. AM offers a considerable departure from traditional manufacturing to rapidly fabricate components with complex internal features. High performance liquid rocket engine combustion chambers that operate in a high heat flux environment are fabricated using a copper-alloy liner with a series of integral coolant channels. Copper-alloys provide the necessary conductivity and material strength for adequate design margins offering high performance without the need for film coolant. Copper-alloys present unique challenges to properly melt the powder in laser-based AM processes due to their high reflectivity and conductivity. Starting in 2014, NASA’s Marshall Space Flight Center (MSFC) and Glenn Research Center (GRC) have developed a process for AM of GRCop (Copper- Chrome-Niobium) alloys using Selective Laser Melting (SLM). GRCop, originally developed at GRC, is a high conductivity, high-strength, dispersion strengthened copper-alloy for use in high-temperature, high heat flux applications. NASA has completed significant material characterization and testing, along with hot-fire testing, to demonstrate that GRCop-42 and GRCop-84 alloys are suitable for use in combustion chambers. Additional development and testing has been completed on AM bimetallic chambers using GRCop-84 liners and superalloy jackets, fabricated using two Directed Energy Deposition (DED) processes: Electron Beam Freeform Fabrication (EBF³) and Blown Powder DED. NASA completed hot-fire testing on various AM chambers using GRCop-84, GRCop-42, and bimetallic chambers in Liquid Oxygen (LOX)/Hydrogen, LOX/Methane, and LOX/Kerosene propellants.

Gradl, Paul R.↗