High Density Of Stacking Faults Research Articles

Achieving high strength and uniform ductility in high-entropy alloys via dynamic-precipitation accelerated transformation-induced plasticity

This study presents a novel approach to fabricating advanced transformation-induced plasticity (TRIP) high-entropy alloys (HEAs) that exhibit an exceptional combination of high strength and uniform ductility, far surpassing the mechanical performance of previously developed TRIP HEAs and non-TRIP multiphase HEAs. The ultrafine-grained Al5Cr20Fe35Co35Ni5 TRIP HEA sample exhibits a yield strength of gigapascal-level, ranging from 1100 to 1260 MPa, with large uniform elongations that range from 29 % to 39 %. Simultaneously, the alloy displays outstanding toughness, reaching 46,000±5390 MPa·%. The achievement of this significant breakthrough rests upon two key factors: (1) achieving an ultrafine-grained FCC matrix in a fully recrystallized microstructure with the aid of thermally induced B2 phase, and (2) dynamic precipitation of nanometer-sized B2 phase particles on high-density stacking faults and slip bands created within the interiors of ultrafine grains. The dynamic precipitation of the B2 phase, facilitated by the formation of an amorphous phase that serves as a precursor to the B2 crystalline phase, is a rare occurrence in HEAs at room temperature. This dynamic precipitation process greatly enhances TRIP-assisted strain hardening (from FCC to HCP phase) of the current alloy at ultrafine grains, enabling the overcoming of the inherent tensile ductility constraints typically associated with ultrafine-grained metals. The current development of TRIP HEAs with an outstanding combination of high strength and high toughness is believed to mark a remarkable milestone in the application field of TRIP HEAs.

Dual heterogeneous structure enabled ultrahigh strength and ductility across a broad temperature range in CrCoNi-based medium-entropy alloy

Developing alloys with exceptional strength-ductility combinations across a broad temperature range is crucial for advanced structural applications. The emerging face-centered cubic medium-entropy alloys (MEAs) demonstrate outstanding mechanical properties at both ambient and cryogenic temperatures. They are anticipated to extend their applicability to elevated temperatures, owing to their inherent advantages in leveraging multiple strengthening and deformation mechanisms. Here, a dual heterostructure, comprising of heterogeneous grain structure with heterogeneous distribution of the micro-scale Nb-rich Laves phases, is introduced in a CrCoNi-based MEA through thermo-mechanical processing. Additionally, a high-density nano-coherent γ' phase is introduced within the grains through isothermal aging treatments. The superior thermal stability of the heterogeneously distributed precipitates enables the dual heterostructure to persist at temperatures up to 1073 K, allowing the MEA to maintain excellent mechanical properties across a wide temperature range. The yield strength of the dual-heterogeneous-structured MEA reaches up to 1.2 GPa, 1.1 GPa, 0.8 GPa, and 0.6 GPa, coupled with total elongation values of 28.6 %, 28.4 %, 12.6 %, and 6.1 % at 93 K, 298 K, 873 K, and 1073 K, respectively. The high yield strength primarily stems from precipitation strengthening and hetero-deformation-induced strengthening. The high flow stress and low stacking fault energy of the dual-heterogeneous-structured MEA promote the formation of high-density stacking faults and nanotwins during deformation from 93 K to 1073 K, and their density increase with decreasing deformation temperature. This greatly contributes to the enhanced strain-hardening capability and ductility across a wide temperature range. This study offers a practical solution for designing dual-heterogeneous-structured MEAs with both high yield strength and large ductility across a wide temperature range.

New approach to produce cubic-WC at low temperature for hydrogen evolution reaction

A novel catalyst, a nanostructured cubic-WC (c-WC) flat film, is introduced for the hydrogen evolution reaction (HER) using a specialized magnetron sputtering system. This method results in over 94% crystalline c-WC0.95 formation at room temperature, featuring high-density stacking faults and twin defects. The catalytic performance of the c-WC film for HER is investigated through theoretical simulations and experimental studies. Density-functional theory (DFT) suggests that the c-WC (100) surface exhibits faster reaction kinetics than c-WC (111) surface, approaching the efficiency of Pt (111) surfaces. Experimentally, the c-WC0.95 film exhibits a high electrochemical surface area and increased active sites due to surface defects. Differential electrochemical mass spectrometry (DEMS) confirms an onset potential for HER of −50.0 mV for c-WC0.95 films and establishes electrodesorption as the rate-determining step. Overall, the c-WC film emerges as a cost-effective and efficient catalyst for green hydrogen production, showcasing excellent reproducibility and electrochemical stability.

Improving the strength–ductility of laser powder bed fusion René 104 through high-density stacking faults induced by Sc and Y microalloying

Improving the strength–ductility is crucial to the development of high-performance nickel-based superalloys fabricated via additive manufacturing (AM). In this study, Sc and Y microalloying is used to regulate the microstructure and improve the strength–ductility of René 104 supealloy (René 104ScY). The results suggest the formation of high-density stacking faults (SFs), Lomer–Cottrell locks, and nano-Al3(Sc,Y) phases in the René 104ScY matrix. The cellular/columnar structures are refined, the number of equiaxial grains increases, and the number of columnar grains and their aspect ratio decrease in René 104ScY. The synergistic effect of multiple strengthening mechanisms, including that formed by SFs, improves the strength and ductility of René 104ScY fabricated via laser powder bed fusion. The yield strength, tensile strength, and elongation of René 104ScY are 1059 ± 15 MPa, 1405 ± 10 MPa, and 28.8 % ± 0.6 %, respectively. This study provides a novel approach for developing high-performance nickel-based superalloys using AM.

Double heterogeneous structures induced excellent strength–ductility synergy in Ni40Co30Cr20Al5Ti5 medium-entropy alloy

The application of single-phase face-centered cubic (FCC) medium entropy alloys (MEAs) in the engineering industry is often hindered by the challenge of insufficient strength. In this study, a novel non-equiatomic ratio Ni40Co30Cr20Al5Ti5 MEA was successfully fabricated. Through the well-designed mechanical heat treatment processing, we introduced a heterogeneous grain structure comprising 67.4% fine grain and 32.6% coarse grain. Additionally, heterogeneous size L12 phases consisting of 18.7% submicron precipitates and 11.7% nano-sized precipitates, were incorporated into the alloy. Tensile tests conducted at room temperature revealed that the double heterogeneous structure alloy demonstrated remarkable strength–ductility synergy. It exhibited a yield strength of 1200 MPa, an ultimate tensile strength of 1560 MPa and a total elongation of 33.6%. The exceptional strength of the alloy can be primarily attributed to heterogeneous deformation induced strengthening, grain boundary strengthening and precipitation strengthening. The excellent ductility is mainly attributed to the high-density stacking faults and Lomer–Cottrell locks. This study not only contributes to the clarification of the strengthening and deformation mechanism of double heterogeneous structure alloys but also provides an effective strategy for the development of high-performance alloys with high strength and ductility.

A novel performance optimization study in additively manufactured tungsten-5 wt.%Rhenium alloys reinforced with dilute carbon

Due to the inherently limited ductility at room temperature, cracks were almost inevitable in additively manufactured tungsten (W). In this study, we propose a novel W-5 wt.%Re-C ternary alloy with exceptional crack suppression fabricated using laser additive manufacturing. We analyze the advantageous effects of solutes on properties of the W matrix and investigate the influence of planar segregation of carbon (C) on active deformation through density functional theory calculations. In the experiment, carbon-based complexes (CBCs) featuring high-density stacking faults achieved through the planar segregation of C atoms were discovered. Infinite solid solution W2C-Re precipitates were also discovered. The formation of CBCs can alleviate stress concentration to facilitate coordinated deformation. This study investigates the influence of C addition on coordinated deformation behavior in W-based alloys, offering a novel approach for optimizing the performance of additive manufactured components based on W.

Combined strengthening from nanoprecipitates, stacking faults and nano-twins enables a strong and ductile medium-entropy alloy

Single-phase face-centered cubic (fcc) alloys typically exhibit remarkable strain-hardening capability and large ductility but possess low yield strength. Conventional strengthening strategies inevitably lead to the loss of ductility. Here, an Nb alloyed CrCoNi-based medium-entropy alloy with a superb yield strength of ∼1.82 GPa, an ultimate tensile strength of ∼1.94 GPa, and good ductility of ∼24 % at 93 K is designed through the combined strengthening from nanoprecipitates, stacking faults, and nano-twins. The cold-rolling is employed to introduce high-density stacking faults and nano-twins, while subsequent low-temperature annealing generates numerous Nb-rich γ″ nanoprecipitates in the fcc matrix. The combined effects of precipitation strengthening, stacking fault- and nanotwin-induced strengthening contribute to an increase in flow stress to surpass the critical stress for the formation of stacking faults and deformation twinning. Moreover, the precipitation of high-density Nb-rich γ″ nanoprecipitates reduces the stacking fault energy of the fcc matrix. Therefore, the precipitation of γ″ nanoprecipitates produces more stacking faults and nano-twins during tensile deformation. The formation of stacking faults and nano-twins in turn, by dynamically introducing high-density interfaces for reducing the mean free path of dislocations, generates a high strain-hardening rate, thus high ultimate tensile strength and large ductility. More importantly, the coherent interfaces between γ′′ nanoprecipitates and the fcc matrix facilitate the transmission of stacking faults and nano-twins across the γ′′ nanoprecipitates. This mechanism could relieve the stress/strain concentrations at interfaces that could otherwise lead to premature crack initiation. This kind of combined strengthening from nanoprecipitates, stacking faults, and nano-twins provides a new avenue to further enhance the strength of nano-twinned materials or precipitation-strengthened materials while maintaining good ductility.

Introducing nano-scale MgO particles into RHQT Nb3Al superconducting wires to significantly improve the critical current density

This research introduced nano-scale particles into the RHQT Nb3Al superconducting wires, which was confirmed by TEM that nanoparticles with size of 5–25 nm distributed in the wires and might act as the extra flux pinning centers. The precursor wires were fabricated by powder in tube process with nano-sized MgO (n-MgO) doped in the raw powder. Uniform microstructure and chemical composition were obtained in the superconducting wires. Besides nanoparticles, high density stacking faults with spacing of 5–20 nm were observed in the Nb3Al superconducting wire, which acted as the dominant flux pinning centers. It had great importance that nanoparticles were introduced into the RHQT Nb3Al wires and combined with the high density stacking faults to significantly improve the critical current density (Jc) of the wires. The magnetic Jc results of 1 wt% n-MgO doped Nb3Al wire were about twice of the non-doped sample, corresponding to Jc values of 3.18 × 105 A/cm2, 2.38 × 105 A/cm2 and 1.72 × 105 A/cm2 at 4.2 K and 8 T, 10 T and 12 T.

Strength-ductility synergy induced by high-density stacking faults in aluminum alloy composites with micro/nano hybrid reinforcements

Strength-ductility synergy induced by high-density stacking faults in aluminum alloy composites with micro/nano hybrid reinforcements

Interface-dominated deformation mechanisms in Cr/CrN/Cr-DLC multilayer triggered by nanoindentation

The diamond-like carbon (DLC) film traditionally possesses low toughness owing to high intrinsic compressive stress. The incorporation of other elements into the DLC film provides an effective approach to improving toughness, but it is still limited and produces some detrimental effects. In this study, a new strategy of designing the Cr/CrN multilayers to serve as a functional transition layer and doping Cr into DLC film is attempted to simultaneously improve the strength and ductility of DLC film. Herein, a profound understanding of the deformation mechanisms of Cr/CrN/Cr-DLC multilayers with different bilayer periods (BPs) during the indentation process is investigated. The maximum strength and toughness values are achieved by the Cr/CrN/Cr-DLC multilayer with BP of 10 nm (P10). The cooperation of multiple strengthening mechanisms involving the diminishment of dislocation motion within individual layers and the formation of coherent twin boundaries (CTBs) and Lomer-Cottrell locks (L-C locks) contributed significantly to the high hardness of P10. The predominant toughening mechanism of P10 is the formation of a substantial number of high-density stacking faults (SFs) in CrN sublayers, which is attributed to that the pre-existed CTBs with numerous kinks in CrN can reduce the stacking fault energies (SFEs) for P10. Few deformation twins facilitated the deformation of P10. In contrast, a versatile deformation mechanism appears in Cr/CrN/Cr-DLC with BP of 100 nm (P100) involving dislocation motion, SFs, deformation twins, and, of particular note, amorphization. However, the released energy related to deformation in P100 is limited, leading to cracks in the Cr-DLC top layer. This multilayer structure can provide additional strengthening and toughening mechanisms to endow the DLC film with profound mechanical properties in harsh service conditions.

Shock-compression microstructure transformation of the additive manufactured FeCoNiAlTi high-entropy alloy

Investigation into the microstructural deformation mechanisms of a high-entropy alloy (Fe28.0Co29.5Ni27.5Al8.5Ti6.5 (at%)) prepared by laser additive manufacturing and aging treatment, with a three-phase nanocomposite structure, is carried out via shock compression experiments using plate impact. Microstructural characteristics and compositions are inspected using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The microstructure of the high-entropy alloy is comprised of high-density dislocation structures, high-volume-fraction L12 nano-precipitates, a small amount of L21 nano-precipitates, and face-centered cubic (FCC) matrix phases. The lattice arrangement of the FCC matrix phase is disordered, with strong segregation of Fe and Co atoms, while Ni, Al, and Ti atoms are predominantly present in the ordered L12 and L21 nano-precipitates. The FCC matrix or the FCC matrix with high-density stacking faults are bounded by a 9R-phase between two phase boundaries. The mechanisms of microstructural transformation of the high-entropy alloy are discussed in detail.

Preparation and Electromagnetic Wave Absorption Properties of N-Doped SiC Nanowires.

Enhancing the conductivity loss of SiC nanowires through doping is beneficial for improving their electromagnetic wave absorption performance. In this work, N-doped SiC nanowires were synthesized using three different methods. The results indicate that a large amount of Si2ON will be generated during the microwave synthesis of SiC nanowires in a nitrogen atmosphere. In addition, the secondary heat-treatment of the as-synthesized SiC nanowires under nitrogen atmosphere will significantly reduce their stacking fault density. When ammonium chloride is introduced as a doped nitrogen source in the reaction raw material, the N-doped SiC nanowires with high-density stacking faults can be synthesized by microwave heating. Therefore, the polarization loss induced by faults and the conductivity loss caused by doping will synergistically enhance the dielectric and EMW absorption properties of SiC nanowires in the range of 2-18 GHz. When the filling ratio of N-doped SiC nanowires is 20 wt.%, the composite shows a minimum reflection loss of -22.2 dB@17.92 GHz, and an effective absorption (RL ≤ -10 dB) bandwidth of 4.24 GHz at the absorber layer thickness of 2.2 mm. Further, the N-doped SiC nanowires also exhibit enhanced high-temperature EMW absorption properties with increasing temperature.

Revealing the interdependence of load partitioning, dislocation density evolution and mechanical behavior of medium Mn steels

The load partitioning between inter-phases and intragranular of austenite, their dislocation density evolution, and mechanical behavior were investigated in two medium Mn steels by in-situ high-energy synchrotron x-ray diffraction during tensile loading. The investigated steels were produced with different hot rolling parameters resulting in different initial microstructures. The initial microstructures were characterized using scanning electron microscope and electron backscatter diffraction analysis. Transmission electron microscope with high angle annular dark field technique was furthermore used to provide the fine microstructural features of deformed specimens in order to supplement the in-situ analysis. Despite the differences in the initial microstructure, the load partitioning from the softer ferrite to the stronger α’-martensite (α’) was observed; while different degrees of load partitioning for intragranular of γ occurred. The sample with a relatively low degree of load partitioning exhibits the intersection of two bundles of stacking faults (SF), one with high density SF, and the other with low density and limited SF, as well as the occurrence of α′ in the intersecting region. The secondary SFs and the relatively intermediate density of primary SFs bundle are characterized in γ for the sample with relatively high degree of load partitioning. The load partitioning between intragranular of γ is found to have a coordination relationship with the dislocation density evolution of γ; after the load partitioning, dislocation density of γ rapidly rises. The sample with intersection of two bundles SFs and the occurrence of α′, exhibits the higher transformation rate of γ into ε-martensite/α’, resulting in the larger work hardening rate. In addition, the early load on α’ is found to contribute to a higher yield strength. These results reveal the importance of assessing both phase-specifc strain/stress and the dislocation density evolution in order to predict the macroscopic mechanical properties of medium Mn steels.

Thermal-induced decomposition and mechanical properties of AlN/CrN superlattice coating

Here, the thermal-induced decomposition and mechanical properties of AlN/CrN superlattice coating with modulation period of ∼8 nm are investigated in detail. Introduction of CrN template layers stabilizes the cubic growth of AlN layers, where the coherent AlN/CrN coating exhibits the higher hardness value of ∼24.1 GPa than CrN (∼16.9 GPa) and AlN (∼18.5 GPa) monolithic coatings. After thermal exposure, the AlN/CrN coating decomposes into stable body-centered cubic Cr and wurtzite AlN via intermediate phases of hexagonal Cr2N and cubic AlN. Especially, the formation of metastable cubic AlN is observed due to the destruction of coherent interfaces. Meanwhile, the thermal load leads to the grain deformation, which causes the change of AlN and CrN sublayers from the crossover to pinch-off to finally dissociation. The driving force of grain deformation mainly arises from the N-loss of CrN sublayers and the high-density stacking faults formation of AlN sublayers. Furthermore, the occurrence of stacking faults and h-Cr2N phase offset the softening effect caused by the thermal decomposition. Correspondingly, the hardness almost remains unchanged between 900 and 1100 °C.

High-pressure and high-temperature induced densely discontinuous nanoprecipitates in multi-principle element alloy

Knowledge of pressure-related microstructural evolution could be beneficial for directionally tuning mechanical performance of materials. Therefore, in this work, a comparison on the precipitates characteristics and mechanical performance of Ni1.5Co1.5CrAl0.2Ti0.1 multi-principle element alloy (MPEA) aged at 800 °C under high-pressure (HP800) or ambient-pressure (AP800) was systematically studied. Results demonstrate both HP800 and AP800 samples exhibit a heterogeneous microstructure consisting of discontinuous precipitate (DP) regions near grain boundaries and continuous precipitates regions in grain interior. However, the volume fraction of DP regions in the HP800 is ∼25.83% higher than that in the AP800. For revealing the intrinsic mechanism, the fully recrystallized matrix Ni1.5Co1.5Cr MPEA was treated by high-pressure. It is found that the plastic deformation occurs, as well as Ni1.5Co1.5Cr MPEA achieves grain refinement via high-pressure and high-temperature (HPHT) because pressure inhibits grain growth and dynamic recrystallization (DRX) process forms the new fine grains. Similarly, in the Ni1.5Co1.5CrAl0.2Ti0.1 MPEA, the grain refinement is also induced by DRX process during HPHT, so as to promote the formation of DP regions. Besides, HP800 reveals a good combination of a yield strength of 801 ± 33 MPa and an ultimate tensile strength of 1249 ± 53 MPa at a good uniform elongation of 41.85 ± 4.03%, owing to high-density stacking faults and Lomer-Cottrell locks. The present finding might provide a fundamental understanding of DRX process under HPHT and a significant guidance for optimizing nano-precipitates via pressure to develop high-performance strengthened MPEAs.

Untra-fine-grained equiatomic CoCrNi medium entropy alloys with high density stacking faults and strengthening mechanisms

This study introduces a powder metallurgy route (a combination of mechanical alloying (MA) and spark plasma sintering) to enhance the mechanical properties of equiatomic CoCrNi medium-entropy alloys (MEAs) using multiple strengthening mechanisms. The yield strength of MEA with an average grain size of 0.41 μm produced by MA is 777 ± 21 MPa, which is 121% higher than that of MEA with grains of 4.55 μm prepared from commercial powders. Additionally, the yield strength of the untra-fine-grained alloy is 231% higher than that of the one produced by casting. Such an enhancement of the strength is attributed to the coordination of the ultra-fine grains, twins, and high-density stacking faults. Moreover, the influence of twins and stacking faults was investigated using molecular dynamic simulations. The intersection of ultra-high density stacking faults generates many immobile dislocation locks and separates the grains into several small parts, leading to a dynamic grain-refinement effect. These findings indicate that MA is an effective way to produce MEAs with superior strength.

Controlling dynamic recrystallization via modified LPSO phase morphology and distribution in Mg-Gd-Y-Zn-Zr alloy

Featured initial microstructures of Mg-11Gd-4Y-2Zn-0.5Zr alloy (wt%) were obtained by adjusting temperatures of solid solution and cooling methods, including island intergranular 18R and 14H LPSO phases with low-density stacking faults, differentially spaced lamellar intragranular 14H-LPSO phases, and network intergranular 18R-LPSO phases with high-density intragranular stacking faults. Effects of these featured LPSO phases and stacking faults on dynamic recrystallization (DRX) behavior were investigated via hot compression. Promoted DRX behavior via particle stimulated nucleation (PSN) is introduced by coexisting intergranular island 18R and 14H LPSO phases and intragranular wide spacing lamellar 14H-LPSO phases, contributing the highest DRX fraction of 42.6%. Conversely, it is found that DRX behavior with network intergranular 18R-LPSO phases and dense intragranular stacking fault is considerably inhibited with the lowest fraction of 22.8%. That is, the restricted DRX due to dislocations pinning by stacking faults overwhelms the enhanced DRX behavior via PSN of island intergranular 18R and 14H LPSO phases. Specially, compared with dense intragranular lamellar 14H-LPSO phases, high-density stacking faults exert a larger inhibition effect on DRX behavior.

Strain Rate-Dependent Anomalous Work Hardening of a Single-Crystalline CoNi-Base Superalloy

The deformation mechanisms operating in superalloys depend on different parameters such as composition, temperature and deformation rate. So far, the transition from shearing by APB-coupled dislocations to shearing under the formation of stacking faults has been studied exclusively as a function of temperature but not as a function of the strain rate. Therefore, interrupted compression tests with strain rates between 10–3 s−1 and 10–5 s−1 were performed on the single-crystalline CoNi-base superalloy ERBOCo-4 at a temperature of 850 °C. The evolution of the defect structures has been analyzed by conventional transmission electron microscopy. A change of the deformation mechanism from APB-coupled dislocation shearing to stacking fault shearing is found to depend on the strain rate. At lower strain rates, an increased stacking fault density is associated with a higher yield strength and higher work hardening rates at the early stages of plastic deformation due to a very high stacking fault density. After approximately 2.0 pct plastic strain, the stress reaches a plateau and decreases subsequently, which is associated with the formation and thickening of twins as shown by high-resolution scanning transmission electron microscopy. At higher strain rates, the work hardening rate is significantly lower in the early deformation stage. The role of segregation to planar defects and the influence of local phase transformations (LPT) at SESFs is further discussed in reference to the influence of the strain rate. The segregation of W as an η stabilizing element is found to be crucial for the formation of a local phase transformation in ERBOCo-4. At higher strain rates the phase transformation is hindered by insufficient W segregation, resulting in a higher twin density.

Fabrication of high-performance CoCrNi medium entropy alloy by laser powder bed fusion: The effect of grain boundary segregation

A CoCrNi composite material with 3 wt% TiC was successfully fabricated by laser powder bed fusion (LPBF). With increasing content of TiC particles, C gradually segregated along the grain boundaries (GBs). The segregation of C improved the grain coalescence, intensified the attraction of the columnar grains, and increased the consumption of the liquid film. Furthermore, the segregation of C led to the formation of Cr23C6 and core–shell structure (TiO2/TiC) nanoprecipitates along the GBs. These precipitates reduced the mobility of the boundaries and restricted the grain growth along the direction of the maximum thermal gradient. Reinforcing the CoCrNi microstructure with 3 wt% TiC yielded optimal results, as the resultant composite microstructure was free of hot cracks, consisted of small grains, and exhibited a more random texture. The high density of wide stacking faults and Lomer–Cottrell locks hindered cross-slip during further deformation at ambient temperature, and twins dominated at elevated temperatures. These nanoprecipitates hindered dislocation propagation at all temperatures. Therefore, the synergistic strengthening effects from the different types of dislocations and nanoprecipitates endowed the CCN-3M alloy with excellent mechanical properties. Ultimate tensile strengths of approximately 1.34 and 0.88 GPa, yield strengths of approximately 1.02 and 0.75 GPa, and elongations of approximately 15.6% and 25.3% were observed at ambient and elevated temperatures (700 °C), respectively. These results indicate that GB segregation is an effective method for suppressing the evolution of hot cracks, thus expanding the scope of LPBF-fabricated components for industrial applications.

Subsurface deformation and crack propagation between 3C-SiC/6H-SiC interface by applying in-situ laser-assisted diamond cutting RB-SiC

Reaction-bonded silicon carbide (RB-SiC) is considered as an excellent optical material in aerospace engineering. However, the multiple complex interfaces and high hardness make it difficult to be precisely machined. In this research, the in-situ laser-assisted diamond cutting was applied to precisely machining RB-SiC. Firstly, Raman spectroscopy was adopted to identify 3C-SiC and 6H-SiC components in RB-SiC. As following, the in-situ laser-assisted diamond cutting was experimentally carried out to analyze the subsurface deformation and fracture in detail. It was clarified that the cross slips and high-density stacking faults significantly enhance the plastic deformation of RB-SiC. Moreover, the dislocations rapidly plugged at the intersection of 3C-SiC/6H-SiC interfaces resulting in the lateral crack which propagates along the [111]//[0001] direction.