Extended Data Fig. 8: Structure and properties of TS-BN ceramics prepared by hot-pressing sintering.

a, XRD patterns of TS-BN ceramics prepared at various conditions (50 MPa and 1,650 − 1,850 °C, 5 min), showing similar diffraction results as those of SPS sintered ceramics (Fig. 1a). The crystal planes of hBN are marked in the figure. Compared with hBN, the introduction of twist-stacked structure results in the left shift of the (002) diffraction peak, indicating an increase in interlayer spacing. Moreover, the additional diffraction peaks between (100) and (004) diffraction lines of hBN appear in twist-stacked structures (Extended Data Fig. 5), causing the high background intensity observed in the diffraction patterns. b, Engineering stress−strain curves during uniaxial compression. The TS-BN samples have a compressive strength up to 773 MPa and fracture strain of 10.2%, demonstrating the reproducibility of large room-temperature deformability and high strength in hot-pressed sintered bulk ceramics. The slight differences in strength and strain of hot-pressing (or SPS) sintered samples are due to the differences in the microstructure (e.g. twist angle and nanoslice thickness) of the samples. c-e, Gradually enlarged HAADF-STEM images, indicating that the bands with different contrasts in the nanoplate correspond to the laminated nanoslices with different in-plane orientations. f-i, HAADF-STEM images collected from the same region at different α-, β-tilt angles: f (10.4°, −10.7°), g (−1.1°, 15.5°), h (−20.2°, 6.8°), and i (−10°, −10°). Red arrows show the appearance of nanoplates with bright and dark bands at different tilt angles in STEM, indicating the prevalence of twisted stacking structures in the ceramic nanoplates.