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A union of surface with rough micro/nano structures and low surface free energy is critical for the preparation of superhydrophobic surfaces. In this study, a rapid one-step pulse electrodepositing method was used to prepare superhydrophobic surfaces on Cu substrates. The electrolyte was prepared with ethanol, myristic acid (CH3(CH2)12COOH) and lanthanum chloride (LaCl3·6H2O). The surface morphology, chemical composition and superhydrophobic property were characterized by SEM, XRD, FTIR, EDX, optical contact angle instrument and high-speed camera. It turned out that the deposited surfaces have micro/nano hierarchical structures mainly being composed of lanthanum myristate. It is found that the optimal water contact angle is approximately 160.3° with a sliding angle of around 5°. The effects of pulse frequency on the surface morphology and wettability were specifically studied and discussed under an equivalent electrolytic time of 10 min. In this way, it can effectively save time and be simply applied to other materials with good conductivity and has a promising wide range application.

In order to research the workpiece materials removal mechanism of Grinding-assisted Electro-chemical Discharge Machining(G-ECDM) of Metal Matrix Composites (MMCs), a good deal of single pulse experiments has been performed in this paper. The crater volume, convex edge, debris, machined surface of G-ECDM have been taken into considerationand it turns out to be that the grinding effect removes the convex edge of the Electro-chemical Discharge Machining (ECDM) crater during the machining of MMCs, the result show that the material removal rate (MRR) of G-ECDM is much higher than that of ECDM and Electrical Discharge Machining (EDM). When compared to the normal ECDM process, it is found that though the Al4C3 phase can be detected in this ECDM condition, no Al4C3 are observed in the processed surface, which indicates a better surface quality. The reason of this phenomenonhas been analyzed theoretically and experimentally. Based on these results, mechanism of the G-ECDM of MMCs was disclosed in this study.

Progress in the crystallography of lath martensitic and lower bainitic transformations is briefly reviewed,followed by a presentation of the experimentally measured crystallographic characteristics of both lath martensite and lower bainite formed in medium-carbon steels containing Si,Mn and Mo.It is found that the bainite plates relate to each other by a relative rotation of54.7°or60°about the normal to their common close-packed planes｛110｝ b ,which ensures a pseudo-｛112｝ b twin relationship between two adjacent plates,and that all bainite variants formed in a single packet keep a unique G-T orientation relationship with the austenite matrix.These two types of OR of lower bainite are similar to that of the lath martensite,respectively.Furthermore,the measured habit planes of both the lower bainite and lath martensite are all｛335｝ f type,which can verify the crystallographic similarity between the lath martensite and lower bainite.