Development and application of tool wear: A review of the characterization of TiC-based cermets with different binders

Thermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, "solvothermal & in-situ growth" method is carried out to prepare "Fungal tree"-like hetero-structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of "suction filtration self-assembly and hot-pressing". When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m·K) and excellent tensile strength of 136.6 MPa, good temperature-voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree-like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers.

With the development of highly integrated and miniaturized electronic devices, silicone rubber composites with good mechanical flexibility, high thermal conductivity and excellent flame resistance have aroused considerable interest in both industrial and research community. However, the effect of different geometries of thermally conductive fillers on the processing, mechanical and thermal properties as well as flame resistance of silicone rubber composites is still not clear. Herein, liquid silicone rubber (LSR) composites filled with three geometries of thermal conductive fillers i.e. spherical-like aluminum oxide (Al2O3), irregular aluminum nitride (AlN) and 2D boron nitride (BN) sheets were prepared by an extremely simple mechanical-mixing process. As expected, incorporation of BN sheets into LSR matrix produces much higher increase in the viscosity, tensile strength and hardness than the corresponding AlN and Al2O3 fillers, respectively. Typically, at a fixed filler loading of 120 phr, the increased thermal conductivity and heating/cooling efficiency of the BN/LSR composites display much better than the corresponding AlN/LSR and Al2O3/LSR composites, e.g. 316, 124 and 88% improvement in thermal conductivity, respectively. Interestingly, the thermal stability and flame resistance of the three composites present unexpected different phenomena. Compared with the pure LSR, the addition of AlN and Al2O3 exacerbates the thermal degradation of LSR chains, while the presence of BN sheets improves the flame resistance of LSR dramatically, which is attributed to the compact BN/silica residue after burning that effectively restricts the heat and oxygen to attack the inside LSR chains. 

Processing, thermal conductivity and flame retardant properties of silicone rubber filled with different geometries of thermally conductive fillers: A comparative study

Thermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, “solvothermal & in-situ growth” method is carried out to prepare “Fungal tree”-like hetero-structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of “suction filtration self-assembly and hot-pressing”. When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m·K) and excellent tensile strength of 136.6 MPa, good temperature-voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices. 

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree‐like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

Poly-(meta-phenylene isophthal-amide) (PMIA) is regarded as an ideal insulating medium for electronic devices owing to its excellent chemical stability and breakdown strength. However, the poor thermal conductivity limited the application under complex electrical-thermal environment. In this work, the size-graded AlN/PMIA composite papers were fabricated, with a multi-scale structure of matrix and fillers, and maintain qualified stability, mechanical strength and electrical insulation properties. With doping 40 wt% of 10 μm AlN and 10 wt% of 200 nm AlN, the optimum paper with in-plane ( λ ∥ ) and out-of-plane ( λ ⊥ ) of optimal paper reached thermal conductivity of 17.3 W/(mK) and 1.96 W/(mK) is obtained, and the breakdown strength increased to 69 kV/mm. The improvement mechanism brought by size-graded fillers was further revealed by the co-simulation of finite element method and loop nesting algorithm. 

Enhanced thermal conductance and electrical insulation of AlN/PMIA composite paper via nano splitting of matrix and size grading of fillers

Polymeric composites with thermally conductive hybrid fillers are significant in the electronics and thermal dissipation , where thermal transport along with multifunctionality is required to meet the application needs. Introduction of hybrid fillers would induce multiple interface scattering and rational design on the filler contact should be the critical criteria, while there is insufficient principle. To promote the thermal transport capability, in this paper, a contact probability model has been established to quantitatively analyze the thermal conductivity and contact probability in the silicone rubber composites with hybrid fillers (including various aluminium oxides and silicon carbide whisker). The results from experiment and simulation suggest that three critical parameters, i.e. volume fraction, filler shape and filler size, are the essential factors of hybrid fillers on impacting the thermal conductivity of composites. With understanding the contact types of hybrid filler, the optimized thermal conductivity has been obtained in the composites with aluminium oxides and silicon carbide whisker fillers. The model and analysis here have provided new contact mechanism for understanding the thermal transport in composites, which could be extended to rationally design and fabricate other types of polymeric composites with hybrid fillers. 

Promoting the thermal transport via understanding the intrinsic relation between thermal conductivity and interfacial contact probability in the polymeric composites with hybrid fillers

Emerging hydrovoltaic technology based on carbon black and porous carbon materials: A mini review

Inspired by Philosophizing of “Point to Area”: Ion Pre-intercalation Induces the Reconstitution of Interlayer Environment of MXene for Lithium Storage

Electroluminescent composites have considerable potential for applications in photoelectric display, electric field measurement and other fields due to their advantages of simple preparation and uniform luminescence. However, high voltage required by the operation of electroluminescent composites hinders their applications in the electric domain, and research on the relationship between electroluminescence principle of composites and filler intrinsic attributes is insufficient. In this paper, the effects of electric field strength, filler mass fraction and voltage frequency on the electroluminescence intensity of ZnS:Cu/epoxy composites are studied, which are majorly used as the luminescent layer of electroluminescent devices. To enhance the electroluminescence intensity of composites, high-temperature sintered BaTiO3 and zinc oxide whiskers (ZnOw) particles are introduced in the base matrix. The finite element method is applied to verify that the matrix of high dielectric constant is in favour of improving the electroluminescence intensity of composites. The band structure of the ZnS:Cu particle is calculated based on the density functional theory + U method to analyse the intrinsic relationship between electroluminescence and particle electronic structure. This paper provides a basis for the research of high electroluminescence intensity devices and will be conducive to better understanding on the relationship between electroluminescence principle and filler intrinsic attributes. 

Optimising the electroluminescence performance of ZnS: Cu/epoxy composites via exploring the relationship between electroluminescence intensity and filler intrinsic attributes

TiC/Ni cermet cladding layer on the surface of 16Mn steel was fabricated with plasma cladding process. Different additions of Mo were 0%, 5%, 10% and 15% in mass percent. The cladding layer was composed of ceramic particles and Ni alloy binder. And the gradient distribution of ceramic particles was observed. And Mo was found in TiC ceramic particles in solid solution. The mechanical properties of the cladding layers with different Mo additions were all better than the cladding layer without Mo. However, the cladding layer with 10% Mo had more defective microstructure and worse mechanical properties.

Miao Liu

Papers

Promoting the thermal transport via understanding the intrinsic relation between thermal conductivity and interfacial contact probability in the polymeric composites with hybrid fillers

Emerging hydrovoltaic technology based on carbon black and porous carbon materials: A mini review

Inspired by Philosophizing of “Point to Area”: Ion Pre-intercalation Induces the Reconstitution of Interlayer Environment of MXene for Lithium Storage

Optimising the electroluminescence performance of ZnS: Cu/epoxy composites via exploring the relationship between electroluminescence intensity and filler intrinsic attributes

Effect of Molybdenum on the Microstructure and Mechanical Properties of TiC/Ni Cermet Cladding Layers