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The development of composite materials with excellent thermal conductivity is attracting extensive attention to meet the increasing heat concentration challenges in both power and electronic equipment. Previous strategies for improving the thermal conductivities usually accompanied by the cost of mechanical strength. Herein, we propose a new strategy for developing both mechanically strong and thermally conductive composite films. The aramid nanofibers (ANF) are well prepared with introducing Ag nanoflakes and graphene oxide (GO) via vacuum-assisted filtration and hot-pressing treatment. Results indicate the synergistic effects of low dimension materials have resulted in a tightly arranged phonon network construction. The in-plane thermal conductivity of the prepared ANF/Ag/GO film reaches 9.84 W m−1 K−1, about 371% higher than that of pure ANF. Meanwhile, the strong hydrogen bond formed between the functional group of GO and the amide group of ANFs plays a synergistic strengthening and toughening role at the complex interface, and the tensile strength reaches 231 MPa. We believe that these findings shed some light on the design and fabrication of multifunctional materials for thermal management applications.

Combining wood plastic composites with 3D printing technology can easily manufacture parts with complex shapes and wood colors, but the single function limits their applications. In this research, Sr2MgSi2O7:Eu2+, Dy3+ phosphors/particleboard wood flour/poly (lactic acid) (SMSED/PWF/PLA) photoluminescence composites for 3D printing were successfully manufactured by melt extrusion. The water resistance and chemical structure of SMSED phosphors modified with five different types of silane coupling agents were characterized by water‐resistance test, Fourier transform infrared spectroscopy, and X‐ray diffraction. It was found that 3‐aminopropyltriethoxysilane (KH550) had the best effect on the modification of SMSED phosphors, formed a dense protective film. Afterward, the effect of KH550‐modified SMSED (KH550‐SMSED) phosphors content on the thermo‐mechanical properties of wood plastic composites was studied. The experimental results indicated that the mechanical properties and thermal stability of wood plastic composites were significantly improved, with the incorporation of KH550‐SMSED phosphors. Finally, based on SMSED/PWF/PLA composites and 3D printing technology, a safety warning model that could emit blue light in the dark and a small dinosaur artwork that could swing flexibly were prepared.

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In this paper, the influence of burial depth of crack on stress measurement of laser cladding coating with the critical refracted longitudinal wave (Lcr wave) was discussed based on the Lcr wave acoustoelastic effect. The regular rectangular slots with different depths that were used to simulate the burial crack in coating was based on the equivalent theory. The experimental system including an ultrasonic wave generator, digital oscilloscope (2.5 GHz sampling rate), and two Lcr wave transducers (2.5 MHz center frequency) was used to collect the Lcr wave under different tensile loads, and the Lcr wave was denoised by using wavelet analysis technology, then the fracture morphology was observed using SEM. The results show that after the denoising by wavelet analysis technology, the signal-to-noise ratio of Lcr wave becomes bigger and the mean square deviation of Lcr wave becomes smaller. When the tensile load is within the turning point load, the difference in time of flight between Lcr wave increases linearly as the tensile load increases, and the deviation of the experimental results becomes obvious as the tensile load increases. When the tensile load is the same, as the burial depth of the slot increases, the nominal Lcr wave acoustoelastic coefficient decreases and tends to be stable gradually. At last, the experimental results are discussed based on the Lcr wave acoustoelastic effect and deformation theory, and it is analyzed that the uneven deformation caused by the interface in coating, anisotropic microstructure, and the burial crack is considered as the main reason.