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Liquid‐phase laser irradiation technology was utilized to synthesize graphene‐coated tungsten carbide (WC@G) core–shell composite materials with regular spherical morphology. Characterization via scanning electron microscopy, transmission electron microscopy (TEM), X‐ray diffraction, and Raman spectroscopy revealed the evolution of WC particle microstructure from sharp edges to regular spherical shapes post‐laser irradiation. High‐resolution TEM displayed a tightly knit core–shell structure. Raman spectroscopy confirmed graphene presence through D, G, and 2D peaks. Incorporation of WC@G into a titanium diboride matrix, followed by discharge plasma sintering, yielded TiB2/WC@G composite ceramic materials. Compared to TiB2/WC/G composite ceramic materials, the WC@G core–shell structure significantly enhanced sintering performance. Optimal mechanical properties were achieved with 6 wt.% WC@G, exhibiting a relative density of 99.6%, Vickers hardness of 18.5 GPa, flexural strength of 696.9 MPa, and fracture toughness of 8.5 MPa m1/2. Characterization identified graphene detachment, pull‐out, and fracture deflection as key mechanisms enhancing toughness in TiB2/WC@G composite ceramic materials. [ABSTRACT FROM AUTHOR]

To improve the mechanical characteristics and machinability of Ti(C,N) cermet and broaden its application range, Al2O3@Ni core–shell powders with varying Ni concentrations were generated using the heterogeneous precipitation-thermal reduction method, and Al2O3@Ni core–shell powders-reinforced Ti(C,N) cermet was created using spark plasma sintering (SPS). The mechanical, microstructural, and sintering characteristics of Ti(C,N) cermet were examined using core–shell powders with varying Ni contents. Al2O3@Ni core–shell powders with appropriate Ni content may uniformly distribute Ni with magnetic solid characteristics in cermet materials, resulting in rapid and uniform discharge that increases interface bonding, improves sintering, and greatly improves overall mechanical qualities. After adding core–shell powders, the cutting force of the TA@30N cermet tool is reduced compared to the TA30N cermet tool, but the surface quality of the machined workpiece improves. The effective cutting distance of the TA@30N cermet tool on heat-treated 45# steel is 36,000 m, 33.33% greater than that of the homogeneous TA30N cermet tool. [ABSTRACT FROM AUTHOR]

To enhance the fracture toughness of B4C ceramics, B4C/TiB2 ceramics with excellent performance were prepared by using TiO2 as the addition item and using spark plasma sintering to introduce TiB2 based on in situ reaction, which was compared with ceramics directly introduced with TiB2, the impacts of TiO2 content, temperature and holding time on B4C/TiB2 ceramics were studied, and the toughening mechanism of B4C/TiB2 ceramics in situ reaction was discussed. The results showed that compared with the ceramics directly introduced with TiB2, B4C/TiB2 ceramics with reinforcement phase TiB2 introduced through in‐situ reaction were easier to obtain higher relative density and better properties. Due to the existence of a discharge effect and the application of pulse current, B4C/TiB2 ceramics with excellent comprehensive properties can be prepared at lower temperatures and short time. When 15 vol% TiO2 was added, the temperature was 1750°C and the holding time was 10 min, the comprehensive properties were better, and their relative density, Vickers hardness, flexural strength, and fracture toughness were 98.5%, 27.72 GPa, 474 MPa, and 5.08 MPa·m1/2, respectively. Toughening mechanisms such as crack deflection, crack branching, and crack bridging improved the fracture toughness. [ABSTRACT FROM AUTHOR]

Based on finite element simulation analysis, laminated ceramic tool materials with different structures were designed and the effect of laminated structure on tool state was investigated. Residual stresses in ceramic tool materials increase with the number of layers and layer–thickness ratio. Based on the simulation results, SiAlON-SiC-SiCw/SiAlON-Al2O3 ceramic tool materials (SCWAs) were prepared using the spark plasma sintering process, and the influence of residual stress on the mechanical properties and microstructure of laminated ceramic tool materials was studied. The mechanical properties of ceramic materials were significantly improved under the effect of residual stresses. The fracture toughness of SCWA4 with 7 layers and a layer–thickness ratio of 6 was 6.02 ± 0.19 MPa·m1/2, and the front and side flexural strengths were 602 ± 19 MPa and 595 ± 17 MPa, 36.3% and 39.0% higher than homogeneous SiAlON ceramics, respectively. [ABSTRACT FROM AUTHOR]

The computer‐aided analysis of microstructure evolution during the sintering process of self‐lubricating ceramic tools can unveil the underlying sintering mechanism and optimize experimental parameters. In this study, a novel self‐lubricating ceramic tool material, Al2O3/SiC/h‐BN@Al2O3, was fabricated with Al2O3 as the matrix, SiC as the reinforcement phase, and h‐BN@Al2O3 as the solid lubricant. The Monte Carlo (MC) method was employed to construct a model of self‐lubricating ceramic tool material, consisting of Al2O3/SiC/h‐BN@Al2O3. Subsequently, the sintering process was analyzed to investigate the influence of particle size and content of reinforced SiC, as well as the content of coated solid lubricant h‐BN@Al2O3, sintering pressure, and temperature on the microstructure of the tool. Optimal composition and sintering parameters were determined: 3 vol% for SiC additive amount with a particle size of 0.05 μm; 5 vol% for h‐BN@Al2O3 additive amount; and an optimal sintering temperature at 1650°C. The development of self‐lubricating ceramic tool materials, Al2O3/SiC/h‐BN@Al2O3, was realized through the employment of the aforementioned parameters. Their mechanical properties and microstructure were comprehensively characterized. The bending strength, fracture toughness, and Vickers hardness of the experimentally‐prepared Al2O3/3 vol%SiC/5 vol%h‐BN@Al2O3 self‐lubricating ceramic tool material were determined to be 722.42 MPa, 6.5 MPa·m1/2, and 20.65 GPa, respectively. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of the concentration and particle size of h-BN nanoparticles in a nanofluid on the surface integrity of 304 austenitic stainless steel during turning, focusing on the cutting force, friction coefficient, cutting temperature, surface roughness, surface residual stress, work hardening capacity, and 3D surface topography. The results show that, compared to dry cutting, the addition of 3 wt.% h-BN nanofluid can reduce the friction coefficient on the rake face by 38.9%, lower the cutting temperature by 43.5%, decrease the surface roughness by 53.8%, decrease the surface residual stress by 61.6%, and reduce the work hardening degree by 27.5%. Two-dimensional profiles and the 3D surface topography display a more balanced peak–valley distribution. Furthermore, by studying the effect of different h-BN particle sizes in nanofluids on the surface integrity of the machined workpiece, it was found that nanoscale particles have a greater tendency to penetrate the tool–chip interface than submicron particles. Moreover, the h-BN particles in the nanofluid play a "rolling effect" and "microsphere" effect, and the sesame oil will also form a lubricating oil film in the knife-chip contact area, thereby reducing the friction coefficient, reducing the cutting force, and improving the machining surface quality. [ABSTRACT FROM AUTHOR]

The interfacial mechanical properties of the alumina/graphene (Al2O3/GR) nanocomposite ceramic tool materials were studied by molecular dynamic simulations. The effects of pull‐out velocity of graphene, system temperature, vacancy defect, and wrinkled graphene on the interfacial mechanical properties were investigated. Results show that a large interfacial shear stress (382 MPa) exists between the Al2O3/GR interface. The maximum pull‐out force and interfacial shear stress increase with increasing graphene pull‐out velocity. The increase of temperature reduces the maximum pull‐out force and interfacial shear stress. Moreover, the load transfer capacity is reduced and the creep of the matrix occurs. These factors reduce the fracture toughness of the Al2O3/GR nanocomposites. A moderate amount of vacancy defects in graphene increases the interfacial pull‐out force and shear stress of Al2O3/GR nanocomposite ceramic tool. Compared with Al2O3/GR nanocomposite ceramic tools, the interfacial interaction energy and shear stress of pleated graphene and Al2O3 were increased by 13.87% and 41.08% respectively, with better toughening and reinforcement. The results are of significance in further understanding of the interfacial mechanical properties at the nanoscale and then beneficial to improve the mechanical properties and engineering performance of Al2O3/GR composite ceramic materials. [ABSTRACT FROM AUTHOR]

For addressing the issue of low relative density, poor fracture toughness of boron carbide ceramics, carbon nanotubes (CNTs)‐reinforced B4C‐SiC ceramic composite material was prepared via spark plasma sintering (SPS), and the impact of CNTs on the strengthening and toughening of the composite was studied. The evidence revealed that an appropriate amount of CNTs can enhance the discharge effect and improve the compactness. As the CNTs content increased, the flexural strength and fracture toughness took on a tendency to first rise and then drop. After mixing.5 wt.% CNTs, the flexural strength and fracture toughness were 499 MPa and 5.38 MPa·m1/2, which increased by 59.4% and 28.4%, respectively. The transformation of fracture mode, grain refinement, bridging and pulling‐out of CNTs efficiently enhance the mechanical properties. [ABSTRACT FROM AUTHOR]

In this study, 3 mol% yttria‐stabilized tetragonal zirconia polycrystal (3Y‐TZP)/Al2O3/graphene nanoplatelets (GNPs) medical ceramic materials for manufacturing surgical scalpels were sintered in vacuum in an SPS–625HF furnace. The mechanical performances and microstructures of the composites were investigated, and the influence mechanisms of the sintering temperature and amount of added GNPs were studied. During the sintering process at 1400°C and 30 MPa for 5 min, the added GNPs enhanced the mechanical properties of the 3Y‐TZP/Al2O3 composites. The results showed that the composite with.1 wt.% GNPs had 6.4% (910 ± 11 MPa) higher flexural strength than 3Y‐TZP/Al2O3. The composite with.4 wt.% GNPs had 38.7% (12.95 ±.22 MPa m1/2) greater fracture toughness than 3Y‐TZP/Al2O3. The main toughening mechanisms of 3Y‐TZP/Al2O3/GNPs were crack bridging, crack deflection, crack branching, GNPs bridging, transgranular fracture structures, and phase transformation of t‐ZrO1.95. The two‐stage densification displacement curve appeared at the optimal sintering temperature of the materials, and the 3Y‐TZP/Al2O3/GNPs composites with a two‐stage densification displacement curve had excellent mechanical properties. The added GNPs can inhibit the grain growth during the sintering process, thereby refining the zirconia grains. With the increase in GNPs content, the grain size and flexural strength of the composites decreased gradually. However, higher content of GNPs was beneficial to improve the relative density and thermal diffusivity of 3Y‐TZP/Al2O3/GNPs composite material. [ABSTRACT FROM AUTHOR]