Eutectic Structure Research Articles

Comprehensive analysis of beryllium content influence on secondary electron yield in Cu[sbnd]Be alloys

This study examines the impact of varying Be contents on the evolution of secondary electron emission (SEE) properties. Through microscopic characterization of the microstructure before and after activation, it was determined that the phase composition was α(Cu) phase and eutectic structure (α(Cu) + γ). The findings indicate that as the Be content increased from 2.8 wt% to 3.8 wt%, the proportion of heterogeneous structures increased and the distribution became more uniform. Meanwhile, the number of heterogeneous structure interfaces between α(Cu) phase and γ phase increased, and there were a large number of mismatch dislocations at the interfaces, which served as short-circuit diffusion paths for Be elements. Be elements were more easily able to diffuse outward through the interface to form a uniform BeO film, thereby increasing secondary electron yield (SEY). In addition, the density of mismatch dislocations near the interface was high, promoting the formation of grain boundaries, which provided more diffusion pathways, allowing Be elements to diffuse outward more easily, thereby generating a uniform BeO film with increased SEY. This study holds significant implications for augmenting the SEY of CuBe dynode electrodes used in photomultiplier tubes (PMTs).

Effect of trace Bi addition on the microstructure and mechanical properties of hypoeutectic Al-Mg-Si-Mn alloy

The effects of Bi on the eutectic structure and mechanical properties of AlMg5Si2Mn alloy were investigated. The results show that when trace Bi is added to the alloy, the eutectic Mg2Si phase in the alloy is successfully refined from long plate-like to fine fiber rod-like and coral-like structure. It is mainly attributed to the precipitation of Bi atomic clusters on the front of the solid-liquid interface and form a component supercooling, in which part of Bi atoms react with Mg atoms to form nanosized Mg3Bi2 particles, which effectively inhibits the rapid growth of eutectic Mg2Si and promotes the branching and refining of eutectic Mg2Si. The strength and ductility of AlMg5Si2Mn alloy containing Bi are significantly improved simultaneously. Compared to the unmodified alloy, the largest tensile strength, yield strength and elongation to failure of the 0.3wt % Bi-modified alloy are increased to 28.04%, 12.3% and 129.1%, respectively. The fracture mode of the alloy changes from brittle fracture to ductile fracture.

A Novel Preparation Approach of Aluminum-Based Functionally Graded Material: Auxiliary Wire Filling Gas Metal Arc Directed Energy Deposition

The 2319-1100 aluminum-based functionally graded material (FGM) with continuous gradient transition interface was fabricated by auxiliary wire filling gas metal arc directed energy deposition (AWF-GMA-DED) process via changing the feeding speed of the auxiliary wire ER1100. The droplet transfer behavior, deposition morphology, microstructure and mechanical property of the FGM wall were analyzed. Results indicate that with increasing feeding speed of ER1100, the droplet transfer mode of the auxiliary wire changes in the manner of large droplet transfer—bridge transfer—continuous transfer, while the droplet transfer of the main wire ER2319 is always stable. As the filling ratio of ER1100 increases, the area of interlayer equiaxed grain band and equiaxed grain size increases gradually, the continuity of eutectic structure at the grain boundary is weakened, and the eutectic structure is refined. When the ER1100 filling ratio increases from 10% to 35%, the microhardness decreases by 13.4%, the tensile strength 7.8%, whereas the elongation and corrosion resistance of the FGM part both improve.

Improving interface joining strength of Ti6Al4V/AZ91D bimetal prepared by compound casting via Ni-coated Ti6Al4V lattice structure

The joining of titanium/magnesium (Ti/Mg) bimetals presents challenges due to the low mutual solubility and absence of metallurgical reactions between Ti and Mg. Herein we utilized the Ni-coated Ti6Al4V lattice structure to enhance the interfacial property of Ti6Al4V/AZ91D bimetal prepared by compound casting. The Box-Behnken design (BBD) was employed to optimize the lattice design. The resulting structure featured struts with a diameter (ds) of 2.4 mm, an aspect ratio (l/ds) ratio of 5.4, a tilt angle (ω) of 57°, and a node-to-strut diameter ratio (dn/ds) of 2.4. The optimized Ti6Al4V lattice structure manufactured by selective laser melting (SLM) exhibited α′ martensite with a high dislocation density, conferring exceptional tensile strength. The rough texture of the lattice surface enhanced adhesion with the Ni coating and improved wetting and reactivity between Ni and AZ91D alloy melt. This resulted in the formation of a serrated metallurgical interface with AZ91D alloy, which was primarily composed of α-Mg + Mg2Ni eutectic structure+τ-Ni2Mg3Al ternary phases. An impressive joining strength of 116.1 MPa was obtained under the optimized lattice structure, and the bimetal joint predominantly fails through the damage of AZ91D, aligning closely with simulated failure predictions.

Microstructure and properties behavior of in situ synthesized with high content (Ti, W) C reinforced In625 by two step-laser direct energy deposition

The formation of sensitive interface cracks and the difficulty in processing high-concentration Ni-based ceramic coatings via direct energy deposition (LDED) present major engineering challenges. To address these, high-quality In625/ceramic coatings with various mass contents of Ti, nickel-coated graphite (Ni3C), and WC were fabricated on QT250 using two-step laser directed energy deposition (TsLDED). The influence of the Ti/C: WC molar mass ratio on the bonding interface, microstructure, phase composition, and mechanical properties of the coatings was analyzed. The results indicated that grains at the In625/ceramic coating interface formed epitaxial growth, ensuring a robust bond. In situ synthesis of (Ti, W) C, WCx (WC and W2C), M23C6, and other precipitated phases were uniformly distributed, enhancing nucleation, refining microstructure, and improving mechanical properties. The addition of Ti facilitated the transformation of WCx to (Ti, W) C. High Ti and C concentrations promoted eutectic structure formation in the matrix phase, enhancing performance. The In625 + 56 % Ti – 14 % Ni3C – 30 % WC composite coating exhibited the highest microhardness and the lowest friction coefficient, with microhardness 5.61 and 3.6 times that of QT250 and In625 coatings, respectively, and a friction coefficient 0.3 times that of In625. Variations in the Ti/C: WC molar mass ratio directly affected the content, proportion, and type of (Ti, W) C, WCx, γ-Ni, and eutectic structures comprising M23C6, NiTix, Ni2W4C, Cr2Ti, and γ-Ni, influencing microstructure evolution and mechanical properties. The TsLDED process thus enables the preparation of In625/ceramic reinforced coatings with improved mechanical properties.

Regulating microstructure and mechanical properties of the as-cast Mg-4Zn-0.5Y-0.5Nd alloy by heat treatment

The Mg-4Zn-0.5Y-0.5Nd alloy was designed and fabricated by conventional casting with subsequent heat treatment to regulate the microstructure and mechanical properties. The microstructure, secondary phase, mechanical properties, and fracture behavior were analyzed to elucidate the influencing mechanism. The results reveal that the as-cast alloy is composed of equiaxed grains with large sizes and discontinuously distributed secondary phases. Moreover, the secondary phase is mainly W-Mg3Zn3Y2, which partly forms the eutectic structure. The solid solution treatment coarsens the equiaxed grains and transforms the secondary phase into near continuous distribution. The Mg41Nd5 phase appears and volume fraction of secondary phase decreases a little. The combining of solid solution and aging treatment increases grain size and volume fraction of secondary phase more or less. Furthermore, the Mg24Y5 phase appears and secondary phases have been changed into semi-continuous distribution. After heat treatment, the average grain size reaches its maximum value of 107.18 μm, and the volume fraction of secondary phase climbs up to 2.73 %. Moreover, the solid solution treatment weakens the crystallographic orientation preference along {0001} but induces diversified crystallographic orientation preference. The heat treatment increases microhardness from 57.2 HV0.1 of the as-cast state to 70.5 HV0.1 of the heat-treated state. Comparatively, the solid solution treatment decreases mechanical properties, while the solid solution and aging treatment increase strength and ductility simultaneously. Especially for the ductility, it has been improved by more than 80 %, which is beneficial to the subsequent thermalmechanical processing greatly.

Eutectic resolidification and ultrafast self-quenching of the microstructure in the surface layer of high-speed steel by scanning electron beam treatment

Improving the service life and efficiency of high-speed steel (HSS) tools remains a formidable challenge. Herein, scanning electron beam (SEB) was employed to modify the surface of M2 HSS. Results revealed that SEB induced eutectic resolidification and ultrafast self-quenching of microstructure in surface layer of HSS. The melted layer exhibited a microstructure comprising martensite, residual austenite, dispersed finely rod-like MC and lamellar M2C eutectic carbides along grain boundaries. Martensite and eutectic carbide grid structure significantly enhanced the hardness and wear resistance of surface layer. Compared to substrate, the microhardness of SEB sample was elevated by more than threefold, reaching 914.7HV0.2, which exceeded the hardness (828.6HV0.2) of conventional quenching treatment. Notably, the wear volume of SEB sample had been reduced to 0.54 × 10−11 m3, resulting in a wear resistance that was 3.8 times greater than that of quenched sample.

Effect of al content on microstructure and corrosion resistance of Zn-Al-Mg alloy

In order to solve the solidification microstructure of Zn-1.7Al-1.1Mg alloy on the surface of steel plate during hot dip plating, the solidification path and microstructure of Zn-1.7Al-1.1Mg alloy were studied by Thermo-Calc thermodynamic software, differential thermal analysis (DSC) and scanning electron microscopy (SEM). The results show that during cooling from melting to room temperature, Zn-1.7Al-1.1Mg alloy begins to precipitate Zn-rich η phase at 386.5 °C, binary eutectic structure consisting of η phase and Mg2Zn11 at 350.0 °C, and ternary eutectic structure consisting of η phase, Al-rich metastable β phase and Mg2Zn11 at 343.4 °C,at 276.7 °C, β phase transforms into stable aluminum-rich α and η phases.

Unveiling exotic multi-scale microstructure transformation and crack formation mechanisms in eutectic ceramic composite by laser powder bed fusion

Laser powder bed fusion (LPBF) represents an advanced and versatile technology. Exploiting its distinctive advantages for direct and rapid fabrication of complex-structured melt-grown oxide eutectic ceramic composite represents a pioneering yet challenging endeavor. In this work, LPBF is creatively employed to fabricate turbine blade-shaped, in-situ ternary eutectic ceramic composite. Through the integration of experimental procedures, Finite element method (FEM) simulations, and numerical analyses, an innovative design and manufacturing of oxide eutectic ceramic composites have been successfully established. Comprehensive FEM simulations, with detailed interface characteristic analysis, have revealed macro-scale cracks induced by intense maximum principal stress, and micro-cracks stemming from significant interfacial energy disparities among the three constituent phases. The applications of rapid solidification and nucleation theories have facilitated profound insights into the formation mechanisms of multi-scale exotic microstructures, including top-layer coarse dendrites, rosette-like spherical internally grown eutectic colony within layers, and columnar eutectic colonies with ultra-fine lamellar eutectic structures. Micro-mechanical property testing reveals enhanced performance in the inter-layer ultra-fine lamellar eutectic structure, which is attributed to a refined eutectic spacing of approximately 61 nm, coupled with distinct and robust bonding interfaces. These groundbreaking achievements, focusing on the processing-microstructure-property relationship in the fabrication of gas turbine blade-shaped solidified eutectic ceramic composite using LPBF, provide invaluable theoretical insights and data. This knowledge is crucial for the LPBF production of high-temperature structural materials, highlighting its significant potential applications in fields of aerospace and mechanical engineering.

Influence of ultrasonic assistance on the microstructure and friction properties of laser cladded Ni60/WC composite coatings

The effects of different ultrasonic vibration powers on the distribution, phase structure, friction and wear properties of WC reinforced particles in laser melted Ni60/WC composite coatings are investigated. The effects of ultrasonic vibration on the microstructure, elemental distribution, crystal orientation, friction and wear properties of the fused coatings are analyzed. The experimental results show that the deposition of WC particles in the lower and middle parts of the coating is significantly improved after the introduction of ultrasonic vibration during the fusion cladding process. In particular, at 600 W ultrasonic power, not only the distribution uniformity of tungsten carbide particles in the coating is optimal, but also the composite coating shows better wear resistance. However, too much ultrasonic power increases the possibility of particle agglomeration. In addition, although the phase pattern of the coating does not change after ultrasonic vibration, the width of the columnar crystalline region of the coating is reduced, and the coating is covered by a homogeneous lamellar nanoscale eutectic structure with the phase compositions of the γ-(Fe, Ni) and M23C6 phases. The ultrasonic vibration improves elemental segregation of the coating, reduces the large number of precipitated phases in the coating, weakens the grain growth orientation, and relieves the local stress concentration in the coating. In addition, the mechanism of the influence of WC particles on the microstructure evolution and wear resistance of the composite coatings is discussed.

Microstructural and Performance Analysis of (TiAl)95−xCu5Nix Coatings Prepared via Laser Surface Cladding on Ti–6Al–4V Substrates

In this study, the surface of (Ti-6Al-4V)TC4 alloy was modified via laser cladding. The elemental composition of the coating was (TiAl)95−xCu5Nix, with Ni as the variable (where x = 0, 3, 6, and 9 at.%). Multi-principal alloy coatings were successfully prepared, and their constituent phases, microstructures, and chemical compositions were thoroughly investigated. The hardness and wear resistance of the coatings were analyzed, and the compositions and interfacial characteristics of the different phases were examined via transmission electron microscopy. The analysis revealed that Ni formed a solid solution and a eutectic structure in the Ti(Al, Cu)2 phase. These findings provide valuable insights into the coating properties. Moreover, reciprocal dry sliding friction experiments were conducted to investigate the wear mechanism. The results revealed a significant increase in wear resistance owing to the formation of a Ni solid solution and changes in the coating structure. Additionally, tensile tests demonstrated that the tensile strength of the coatings initially increased and then decreased with varying Ni content. By combining these results with various analyses, we determined that the coating exhibited optimal properties at a Ni content of 6 at.%. Overall, this study comprehensively investigated the microstructure and phase transition behavior of these coatings through various analytical techniques. These findings provide valuable guidance for further optimizing both the preparation process and the performance of the coatings. The coatings exhibit excellent wear resistance and could inspire the design of more advanced protective surfaces.

Microstructural evolution and mechanical properties of Al-4Ni-0.4V alloyed with Zr and Ti at elevated temperatures

The influence of Zr and Ti alloying on the microstructural evolution and mechanical properties of an Al-4Ni-0.4V alloy at elevated temperatures was investigated. The results showed that the coarsening rate of the eutectic Al3Ni phase in the Al-4Ni-0.4V-0.2Zr-0.2Ti alloy decreased from 21.1 nm3/s in the Al-4Ni-0.4V alloy to 7.4 nm3/s after annealing at 350 °C for 0 h to 120 h. The tensile strength, yield strength, and elongation at room temperature of the annealed Al-4Ni-0.4V-0.2Zr-0.2Ti alloy (350 °C, 8 h) were 181 MPa, 108 MPa, and 27.2 %, respectively. After tensile test at 350 °C, these values of the annealed Al-4Ni-0.4V-0.2Zr-0.2Ti alloy were 108 MPa, 72 MPa, and 29.8 %, respectively. Transmission electron microscopy results revealed the precipitation of the L12 ordered structure of the Al3M (M = Zr, V, Ti) phase, approximately 2 nm in size, in the α-Al after annealing. These phases exhibited excellent lattice matching with the α-Al and considerable precipitation strengthening. Segregation of Zr, V, and Ti elements at the α-Al/Al3Ni interface hindered Ni diffusion in the matrix, thereby reducing Al3Ni phase coarsening. Moreover, the Al3M phase precipitated at the interface exhibited favorable matching with the lattice planes of the α-Al and Al3Ni phase, which improved the thermal stability of the eutectic structure and the mechanical properties at elevated temperatures.

Microstructure and mechanical properties of the C/C composites and Nb joints brazed with CoCrFeNi HEAs

A robust brazing of C/C composites and Nb was achieved using CoCrFeNi high-entropy alloys (HEAs) with complete FCC structure. The effects of brazing temperature and holding time on microstructural evolution and mechanical properties of joints were evaluated. The filler infiltrated into the pores of the C/C composites and formed a mixture of FCC and carbides, expanding the bonding areas and interlocking the interface. Moreover, a lamellar eutectic structure composed of FCC and Laves formed in situ near Nb side, providing unique high-temperature performance. The optimal average shear strength of 29.1 MPa at room temperature and 23.6 MPa at 800 °C were obtained at 1260 °C for 10 min. The joining and fracture mechanism of brazed joints were also revealed.

Towards enhanced elevated-temperature mechanical properties by regulation of eutectic structure in Al-Cu-Si alloys solidified under super-gravity field

High volume fraction of tri-phase eutectic structure is challenging to obtain in ternary alloys through conventional methods. Currently, we reported that super-gravity solidification can be utilized to obtain high-volume fraction Al-Al2Cu-Si tri-phase eutectic structure in Al-Cu-Si alloys. The refinement of the eutectic structure can be detected mainly due to the enhancement of mass transfer, affecting the nucleation rate and growth of eutectic phase in the Al-Cu-Si eutectic system. Interestingly, the refined Al2Cu and Si eutectic structures are stable even up to 300 °C thermal exposure without obvious coarsening, contributing to the enhancement of elevated-temperature mechanical properties (∼268.8±8.8 MPa at 300 °C), which is ∼51.9 % higher than those solidified under normal gravity field (∼177.0±1.9 MPa). The refinement and homogeneous distribution of more Al-Al2Cu-Si tri-phase eutectic structures provide better stress dispersion, favoring crack initiation and propagation within the tri-phase eutectics, resulting in a transition from brittle fracture to ductile fracture mode.

Refinement of eutectic structure and precipitates of Cu–20Ag alloy due to Y microalloying

Copper-silver alloy rod with high mechanical properties and stable conductivity are the key materials for the preparation of microfilaments used in endoscopy and other medical fields. In this paper, the microstructure of Cu–20Ag rod was regulated by adding trace rare earth Y in order to improve the comprehensive performance of copper-silver alloy further. and studies the distribution and existence of rare earth Y as well as the influence on the performance of copper-silver alloy rod billet. The results of research show that: rare earth Y mainly exists in the branching nodes of the eutectic organization, so that the alloy in the solidification of constitutional supercooling increases, thus refining the eutectic structure, and make it uniformly distributed. After addition of 0.01 wt%Y, Cu4Y was precipitated in the eutectic structure of the rod. After adding 0.03 wt%Y, the precipitates types increased to trace intermetallic compound AgY and nanoparticles Cu4Y. The increase of the interface between eutectic structure and Cu matrix decreases the electron scattering probability. This is the main factor to lead to the decrease of electrical conductivity. The precipitation hardening of precipitated phase and the increase of interface between eutectic structure and Cu matrix are the main factors for the increase of tensile strength of bar billet. The main factor of the decrease in the conductivity of rod billet is the increase of Ag phase dissolved in eutectic structure and the interface between eutectic structure and Cu matrix.

Study on corrosion mechanism of laser-clad Ni-WxC coating by in-situ electrochemical method under high temperature and pressure environment

Corrosion protection of oil and gas equipment by laser cladding technology has emerged as a crucial method to reduce costs and increase efficiency. The in-situ electrochemical method was employed to investigate the microstructure evolution and corrosion mechanisms of laser-clad Ni1725-WxC coatings under high temperature and pressure environment. The coating is composed of cellular γ-Ni (W, Cr, Fe), block W2C, WC/W2C eutectic structure with a shell of WC, and small amount of CrxCy (Cr7C3/Cr23C6) in Ni1725 matrix. The corrosion resistance of the coating is worsened with increasing temperature under in-situ electrochemical method owing to reduced reaction activation energy and increased transfer rate. Furthermore, the surface potentials of the coating follow the order: E1 (WC shell) > E2 (Ni1725 matrix (oxide)) > E3 (WC/W2C eutectic phase) > E4 (block W2C). Therefore, galvanic corrosion occurs between WC shell and Ni1725 matrix. W2C with lower potential corrodes preferentially as well at WC/W2C eutectic structure in WxC particle, which expands with increasing temperature to form a loose internal structure.

Electrochemical corrosion behavior and passive film properties of Fe2Ni2CrV0.5Nbx (x=0.2, 0.4, 0.6, 0.8) eutectic high-entropy alloy coating prepared by laser cladding

The phase composition, microstructure morphology, and corrosion behavior of Fe2Ni2CrV0.5Nbx (x=0.2, 0.4, 0.6, 0.8) eutectic high-entropy alloy (EHEA) coatings produced via laser cladding were investigated. The research delved into discerning the phase structures and microstructural variations of the EHEA coatings concerning differing Nb compositions. The findings highlighted a direct correlation between Nb content and the volume fraction of the eutectic structure, specifically the FCC/Laves phases. Electrochemical evaluations, including diverse tests such as potentiodynamic polarization, electrochemical impedance spectroscopy, cyclic polarization, Mott-Schottky measurements, and X-ray photoelectron spectroscopy, revealed distinct corrosion behaviors among the EHEA variants. Notably, the Fe2Ni2CrV0.5Nb0.2 coating exhibited relatively superior corrosion resistance compared with Fe2Ni2CrV0.5Nbx (x=0.4,0.6,0.8) coatings, attributed to its lower corrosion current density (Icorr) and the formation of a thicker passive film with prolonged passivation duration. Conversely, the Fe2Ni2CrV0.5Nb0.8 coating, characterized by increased eutectic structures and grain boundary density, yielded a thicker yet non-uniform passive film with higher vacancy defects. This comprehensive exploration into the corrosion behavior and passive film properties of these EHEA coatings provides a reference for designing materials that hold promising implications for future corrosion-resistant material development in industrial parts repair applications.

300 MPa grade high-strength ductile biodegradable Zn-2Cu-xMg (x = 0.08, 0.15, 0.5, 1) alloys: The role of Mg in bimodal grain formation

300 MPa grade biodegradable Zn-2Cu-xMg (0.08, 0.15, 0.5, and 1 wt.%) alloys with different bimodal grain structures were obtained by casting and hot extrusion. The effects of the Mg element on the microstructure, mechanical properties, and dynamic recrystallization (DRX) behavior of the as-extruded Zn-2Cu-xMg alloys were investigated. The obtained results showed that CuZn4 butterfly particles and eutectic net structure (η-Zn + Mg2Zn11) are formed in the as-cast Zn-2Cu-xMg alloys. The as-extruded Zn-2Cu-0.08Mg and Zn-2Cu-0.15Mg alloys exhibited finer DRXed and coarser unDRXed grains with an average grain size of 8.5–8.8 μm, while Zn-2Cu-0.5Mg and Zn-2Cu-1Mg alloys were almost composed of completed DRXed grains with an average grain size of 4.2–6.5 μm. Nanoprecipitates ε-CuZn4 were uniformly precipitated in both DRXed regions and unDRXed regions. Continuous DRX (CDRX) and twinning-induced DRX (TDRX) were the main mechanisms at a low Mg content; Discontinuous DRX (DDRX) and particle-stimulated nucleation (PSN) were strengthened with the addition of Mg. The improved yield strengths in Zn-2Cu-xMg originate from grain boundary strengthening, Orowan strengthening, and hetero-deformation-induced (HDI) strengthening. The fracture elongations are mainly affected by the synergistic effect of bimodal grains, non-basal < c + a > dislocations, and the secondary phases.

Microstructure and performance of joint of Al/Cu welded by resistance element welding with an auxiliary gasket

A 1060 commercial-purity aluminum and T2 pure copper plates with a thickness of 2 mm were welded by using resistance element welding with an aluminum rivet and auxiliary gasket. The interfacial microstructure was analyzed, and the tensile shear load of the joint was tested. In the joint welded, a layer of Al2Cu adjacent to the copper and the eutectic structure of Al2Cu + (Al) near the nugget region were formed at the interface of Al/Cu. The tensile shear load of the joint increased first and then decreased with the increase of welding current, and it reached the maximum of 2.24 kN when the welding current was 26 kA. The results reveal that the application of the auxiliary gasket not only promote the thickening of the nugget, but also achieve the joining between the rivet leg and the upper plate when resistance element welding of Al/Cu is performed.

Unique achondritic impact debris in the CH3 chondrite Acfer 182

The metal-rich CH carbonaceous chondrites contain abundant xenolithic clasts originating from different regions of the Solar System. In the CH3 chondrite Acfer 182, we identified two phosphide spherules (one 95-μm in diameter and the other 50μm×60μm) of schreibersite ((Fe,Ni)3P) and barringerite ((Fe,Ni)2P) with kamacite eutectic structures. These objects are likely to have formed during an impact between planetesimals during the debris-disk phase of the protoplanetary disk before being incorporated into the CH chondrite parent body. In the same sample we identified a 130μm×60μm heideite grain (iron‑titanium sulfide: (Fe,Cr)1.15(Ti,Fe)2S4) with exsolution lamellae of calcium-rich titanium oxide. Thin veins of shock-induced kamacite cross-cut the oxide lamellae, suggesting that it was ejected into the protoplanetary debris disk during an impact event before eventually being accreted by the CH chondrite parent body. This assemblage is distinct from heideite grains found in enstatite chondrites, aubrites, and the Kaidun meteorite. We propose that this object originated from a highly-reduced planetesimal in the inner Solar System that may have been similar to proto-Mercury.