The development of scalable Out-of-Autoclave (OoA) in-situ thermoset curing methods are required to overcome important drawbacks related to the autoclave-based processing methods typically used in industry. The incorporation of graphene, an electrothermal carbon nanomaterial with the ability to transform electric energy into heat through Joule heating, emerges as a promising route to replace the conventional processing methods. In this work the electrical behaviour of both uncured and oven cured GNPs/epoxy composites with loadings of up to 10 wt.% were evaluated and electrical percolation thresholds were established for both. Above the critical loading found for oven cured materials (~ 8.5 wt.%) the electrically conducting networks of GNPs formed in the matrix showed the ability to act as integrated nanoheaters when an electric current was passed through them, successfully curing the composites by Joule heating. Composites prepared by this OoA curing method (as an alternative to the traditional oven based one) at 10 wt.% loading of GNPs were also prepared and compared to the oven cured ones. They showed more compact composite 2 structures, with less microvoids and a preferred orientation of the GNPs in the matrix relative to the oven cured material at identical loading, as revealed by electron microscopy and polarized Raman spectroscopy, respectively. This microstructure and anisotropy induced by the electrically-induced (i.e. OoA) cure led to GNPs/epoxy composites with superior electrical and mechanical properties (revealed by tensile testing). The well-distributed GNP nanoparticles acting as nanoheaters integrated in a thermosetting matrix, in combination with excellent mechanical and electrical performances achieved for the overall graphene/epoxy composites and the simplicity associated to the method, should open the door to novel industrial applications.

There has been a substantial growth in using carbon fiber-reinforced plastic (CFRP) composite materials in aerospace and automotive industries due to their superior properties. This experimental study presents results from a comprehensive and systematic study investigating the effects of cryogenic cooling on drilling performance and surface integrity characteristics of CFRP composite material. Experimental data on cutting edge radius of drill bit, outer corner wear of drill bit, trust force, torque, delamination factor, and surface integrity characteristics, including borehole subsurface damage and diameter error of drilled hole, are presented and analyzed comparing dry drilling with cryogenic cooling of CFRP composite material. The findings demonstrate that cryogenic cooling has a profound effect on reducing the cutting edge rounding of drill bit and outer corner wear; it also helps enhancing the surface integrity characteristics of produced hole. However, cryogenic cooling generates larger thrust force, torque, and thus larger delamination factor.

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Suitable electrothermal materials with high heating rates at low electric power are highly desirable for de-icing and thermal management applications. Herein, 3D epoxy resin/Ti 3 C 2 T x MXene composites are synthesised and shown to be promising candidates for electrothermal heaters where the MXene serves as a nanoheater and the epoxy resin spreads the heat. A unidirectional freeze-casting technique was used to prepare an anisotropic Ti 3 C 2 T x aerogel into which epoxy resin was then vacuum infiltrated and cured. The resulting composite showed an excellent Joule heating performance over repeated heating-cooling cycles. A steady-state temperature of 123 • C was obtained by applying a low voltage of 2 V with 5.1 A current, giving a total power output of 6.1 W cm −2 . Such epoxy/MXene aerogel composites, prepared by a simple and cost-effective manner, offer a potential alternative to the traditional metal-based and nanocarbon-based electrothermal materials.

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CNC ultrasonic machining is an effective method to machine hard and fragile materials. It can realize producing complicate-shaped parts with simple tools. Mechanism of CNC ultrasonic machining was presented. The main components of CNC ultrasonic machine tool were analyzed, including the principle of the ultrasonic generator, selecting suited transducer, designing appropriate horn and impedance matching of tools. Finally, developing tendency of the CNC ultrasonic machining was discussed.

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Rotary ultrasonic machining (RUM) is widely used for machining virous kinds of hard-brittle materials. This article aims to study ultrasonic machining surface quality of zirconia ceramic, low-carbonsteel boltwith self-developed rotary ultrasonic machine. The surface roughness could be detected and observed by Taylor Hobson surface roughness instrument and Keyence microscope.The experimental resultsshow that the surface quality achieved by rotary ultrasonic machining is better than bytraditional mechanical machining. Rotary ultrasonic machininghas advantages for machining hard-brittle materials.