The coaxial laser has been introduced to shaped tube electrochemical machining (STEM), referred to as Laser-STEM, to enhance the materials removal rate and precision. To address the issue of central residual formation during the Laser-STEM process, which limited the machining stability and feeding rate, the retracted hybrid tubular electrode was applied. The formation mechanisms and effects of the W-shaped central residual were analyzed. Simulation and experiments were conducted to study the impact of the retracted length of the tubular electrode. Simulation results showed that a retracted length of 1-1.5 mm of the inner low-refractive layer could improve the electric current density distribution homogeneity to remove the W-shaped central residual in the machining area. The electric current density distribution homogeneity in the machining zone has been decreased by 38% by utilizing the hybrid tubular electrode with a retracted length of 2.0 mm. With a proper retracted length, the laser coupling efficiency exceeded 74.5%. Hence, the retracted hybrid tubular electrode could act as both the tool electrode and optical waveguide in the Laser-STEM process. Experimental results proved that the machining efficiency and precision of Laser-STEM could be enhanced by utilizing the retracted hybrid tubular electrode. With the retracted length deg rising from 0 mm to 1.5 mm, the maximum feeding speed increased by 373%, and the machining precision was improved by 42.2%. The maximum feeding rate of 4.1 mm/min has been achieved using the retracted hybrid tubular electrode in the Laser-STEM process, which has been improved by 105%, compared with the available maximum feeding rate of the tubular electrode in the STEM process. Finally, the small holes with a diameter of 1.4 mm and an aspect ratio of 15 have been processed by Laser-STEM with the retracted hybrid tubular electrode.
Conductive hydrogels with high electrical conductivity, ductility, and anti-dryness have promising applications in flexible wearable electronics. However, its potential applications in such a developing field are severely hampered by its extremely poor adaptability to cold or hot environmental conditions. In this research, an “organic solvent/water” composite conductive hydrogel is developed by introducing a binary organic solvent of EG/H2O into the system using a simple one-pot free radical polymerization method to create Ti3C2TX MXene nanosheet-reinforced polyvinyl alcohol/polyacrylamide covalently networked nanocomposite hydrogels (PAEM) with excellent flexibility and mechanical properties. The optimized PAEM contains 0.3 wt% MXene has excellent mechanical performance (tensile elongation of ~1033%) and an improved modulus of elasticity (0.14 MPa), a stable temperature tolerance from −50 to 40 °C, and a high gauge factor of 10.95 with a long storage period and response time of 110 ms. Additionally, it is worth noting that the elongation at break at −40 °C was maintained at around 50% of room temperature. This research will contribute to the development of flexible sensors for human-computer interaction, electronic skin, and human health monitoring.
The fabrication of deep microgrooves has become an issue that needs to be addressed with the introduction of difficult-to-cut materials and ever-increasing stringent quality requirements. However, both laser machining and electrochemical machining could not fulfill the requirements of high machining efficiency and precision with good surface quality. In this paper, laser and shaped tube electrochemical milling (Laser-STEM) were initially employed to fabricate microgrooves. The mechanisms of the Laser-STEM process were studied theoretically and experimentally. With the developed experimental setup, the influences of laser power and voltage on the width, depth and bottom surface roughness of the fabricated microgrooves were studied. Results have shown a laser power of less than 6 W could enhance the electrochemical machining rate without forming a deep kerf at the bottom during Laser-STEM. The machining accuracy or localization of electrochemicals could be improved with laser assistance, whilst the laser with a high-power density would deteriorate the surface roughness of the bottom machining area. Experimental results have proved that both the machining efficiency and the machining precision can be enhanced by synchronous laser-assisted STEM, compared with that of pure electrochemical milling. The machining side gap was decreased by 62.5% while using a laser power of 6 W in Laser-STEM. The laser-assistance effects were beneficial to reduce the surface roughness of the microgrooves machined by Laser-STEM, with the proper voltage. A laser power of 3 W was preferred to obtain the smallest surface roughness value. Additionally, the machining efficiency of layer-by-layer Laser-STEM can be improved utilizing a constant layer thickness (CLT) mode, while fabricating microgrooves with a high aspect ratio. Finally, microgrooves with a width of 1.79 mm, a depth of 6.49 mm and a surface roughness of 2.5 μm were successfully fabricated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.