No abstract

Superhydrophobic surfaces are extremely susceptible to damage, which can lead to a sharp decrease in their service life and physical properties. Therefore, developing methods to impart superhydrophobic surfaces with excellent wear resistance is crucial. In this article, a flexible carbon fiber brush was utilized as an electrode to fabricate micro-/nano-structures on a grooved surface via electric discharge machining in one step, resulting in a superhydrophobic coating with excellent wear resistance. Carbon fiber brushes exhibit several notable properties, including excellent flexibility, conductivity, and high temperature resistance. Carbon fiber brushes can adapt to the complex inner walls of grooves. Many nano-structures were fabricated on the grooves via pulse discharge, which resulted in a superhydrophobic surface with excellent wear resistance. The contact angle (CA) and sliding angle of the surface after discharge were 156.3 and 2°, respectively. The processed surface exhibits superior corrosion resistance compared to the stainless-steel substrate. The influence of the micro-groove shapes on wear resistance was tested. The results showed that, after 500 cm of wear, the shallow grooves retained their superhydrophobicity with a CA of 150.1°.

No abstract

No abstract

No abstract

No abstract

No abstract

An electrical discharge machining process with a high electrode rotation speed (EDM-HS) has been developed to solve the problems of the conventional EDM process in machining metal matrix composites (MMCs). The EDM-HS process employs a non-round tool electrode. The experiment results showed that the materials removal rate (MRR) of the workpiece can be improved significantly by employing a non-round tool electrode. The relationship between the pulse duration, machining current, duty cycle, the rotation speed of the tool electrode and the MRR has been studied respectively. And the machining mechanism of this EDM-HS process has been analyzed both theoretically and experimentally. The results showed that the non-round electrode can enlarge the machining gap and with a high electrode rotation speed, the machined debris can be discharge out of the machining area effectively and hence a stable machining condition can be obtained. As a result, a higher MRR can be achieved. Moreover, an orthogonal analysis has been utilized to study the relative importance of the machining parameters on MRR. It was found that to obtain the highest MRR, the electrode rotation speed was the most influential factor among the duty cycle, machining current, pulse duration and electrode rotation speed. This outcome supports that it is feasible to use this novel method to machining particulate reinforced MMCs, where a higher MRR can be achieved.