Adhesive bonding is widely used in the joining of metals and carbon fiber-reinforced plastics (CFRPs). Ultrasonic vibration was used to improve adhesive bonding of CFRP/Al alloy joints grafted with silane coupling agent, and the effect of the ultrasound on the bonding was studied. The surface of Al alloy was treated with a silane coupling agent, and then the ultrasonic vibration was applied on the adherend during the adhesive bonding process. The shear strength was tested, and the mechanism was analyzed by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). It is found that the ultrasonic assisting can further promote the bonding of the Al alloy and the adhesive. For the test joins, the shear strength was increased by 267.50% using the silanization treatment plus the ultrasonic assisting. The ultrasonic assisting promoted the grafted epoxy group to react with the adhesive more sufficiently at the Al/adhesive interface by causing micro-mixing and intensified molecule collision, and thus more chemical bond was formed. Under the ultrasonic action, the interface and the adhesive layer became tighter owing to the impact contact at the interface and the oscillating flow in the adhesive layer. The ultrasonic vibration assisting increased the bonding strength by promoting the chemical bond and improving physical morphology.

In this study, steel/aluminum bimetal gears were manufactured under different deformation degrees by using hot forging processing. Optical microscope (OM), scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS) were used to observe morphologies and the element composition of the interface region of the bimetal gears with different deformation degrees. Results show that the interface region between steel and aluminum is of mechanical bonding characteristics when the deformation degree is 50% and 70%, and the steel–aluminum interface joining zone is of the metallurgical bonding feature when the deformation degree is 90%. Finite element (FE) simulation of the hot forging process of the bimetal gear was carried out by using DEFORM-3D software. The simulation results show that the increase in the difference between the interfacial radial stress and the flow stress of the steel helps to form metallurgical bonding at the steel–aluminum joining zone.

In wire arc additive manufacturing, residual stress is generated from a nonuniform thermal distribution, resulting in the fabricated component demonstrating large deformation. This study explored the effects of electroshock treatment (EST) on the residual stress and geometric dimensions of additive manufacturing components. A special and innovative stress frame was built with wire arc additive manufacturing, on which the EST was conducted. Changes in the residual stress, geometric dimensions, temperature, microstructure, and dislocation distribution on the stress frame during processing were investigated. According to the experimental results, it was concluded that the dislocation density decreased and that the distribution was more homogeneous after EST, which was affected by electron wind force. Finally, the residual stress was reduced, and the geometric dimensions were improved on the substrate.

Hot-deformation pre-bonding is a newly developed method to avoid smelting defects in large stainless steel billets, in which the high-quality interfacial connection needs to be realized as a key guarantee. In this work, a novel electromagnetic shocking treatment (EST) method, as a special way to apply an external physical field, was proposed to introduce the hot-deformation pre-bonded austenitic stainless steel. It is demonstrated that EST can efficiently optimize the hot-deformation pre-bonded interface and restore the tensile properties of pre-bonded stainless steel within several seconds. The interface healing behaviors induced by EST were analyzed via the in situ observation of an optical micrograph, scanning electron micrograph, as well as electron backscattering diffraction. The optimization of the interface connection is mainly attributed to the fact that EST can act on the interface locally, leading to the healing of voids at the interface accompanied by a reduction in stress and the decomposition of oxide. In addition, EST plays another important role in adjusting the texture difference at both ends of the interface, which can further improve the mechanical properties. The results suggest that EST exhibits great potential in promoting the hot-deformation pre-bonding of large billets.