Bipolar resistive switching (RS) and synaptic behaviors of resistive random access memory (RRAM) based on TiO x are demonstrated. RS uniformity is improved by introducing nitrogen into the RS layer using radio frequency sputtering in the reactive Ar/N2 ambient. The conductive mechanism is in good agreement with the space−charge‐limited conduction model. The activation energy fit by the Arrhenius equation and conductive atomic force microscopy results indicate that the conductive filaments are formed by oxygen vacancies. More importantly, reliable multilevel RRAM can be achieved by tuning the compliance current, which enables the achievement of distinguishable resistance states. Furthermore, multilevel RRAM enables the simulation of synaptic functions, such as learning−forgetting−relearning, habituation, and spike‐timing‐dependent plasticity (STDP). Image pattern recognition based on STDP learning rules using a digital memristor is demonstrated. The findings may offer a route to the development of future storage and neuromorphic computing.

The hydroforming process of the aluminum alloy panel was simulated by the software DYNAFORM. The effects of process parameters (blank holder force, depth of panel and height of draw bead) on springback of the aluminum alloy were investigated. The max springback of the panel was analyzed by weighted scoring method. Then the process parameters were synthetically optimized for the max positive and negative springback. The results showed that the height of draw bead affects obviously the comprehensive springback of the panel. The optimization of the process parameters obtained by the orthogonal experiment can effectively reduce the max springback of the panel.

The viscous pressure forming (VPF) was applied to form an automotive aluminum alloy panel in this paper. The formability of the panel was investigated. Further, the springback characteristics of the panel were analyzed. The results show that the viscous medium is helpful to improve the flow of the sheet blank. The positive and negative springback occur for the panel formed by VPF. It is different from the panel formed by rigid punch forming, in which only the positive springback occurs. Furthermore, the springback value of the panel formed by VPF is smaller than the latter.

The static dent resistance performance of the aluminum alloy panel formed using viscous pressure forming (VPF) is studied by experimental methods. The successive load is used to cause the aluminum alloy panel dent in the static dent resistance test. The influence of the curvature radius and VPF process parameters on the static dent resistance performance is researched. Results show that the panel with the smaller radius has a larger stiffness and static dent resistance; the adequate drawing depth can optimum the static dent resistance performance of the double-curved panel and the drawbead also can increase the stiffness and static dent resistance.