[en] Diamond coating were deposited on cemented carbide inserts by DC plasma jet CVD. The cemented carbide inserts were pretreated by methods including chemical etching of Co, Ar/H₂ plasma etching. The characteristics of diamond film, interface structure, adhesion strength and film stress were analysized by different methods such as SEM, XRD, Raman spectrum etc. A comparing experiment of cutting Al - 22 % Si alloy was carried out with diamond-coated cemented carbide inserts and uncoated cemented carbide inserts. The results show that the diamond-coated cemented carbide insert has a great advantage for cutting abrasive high content Al - Si alloy. (author)

[en] Highlights: → The mixed amorphous-nanocrystalline microstructure LiV₃O₈ thin film underwent a slow degradation process during prolonged cycling. → This paper reveals the capacity fading mechanism for LiV₃O₈ film electrode. The composition of surface layer has been confirmed by XRD and TEM. → This research gives evaluable improvement proposal for further modifying LiV₃O₈ film electrode materials. - Abstract: The electrochemical behavior related to cycle performance and capacity fading for LiV₃O₈ thin-film positive electrodes has been investigated. These electrodes experience a slight capacity loss over an initial 200 cycles, and the capacity decreases rapidly upon further cycling. This two-stage capacity fading is related to the growth of a surface layer and exfoliation of active materials, which occurs at different stages of the cycling period. The growth of the surface layer is a major reason for the increased impedance. However, it can prevent the dissolution of active materials and retard further electrode degradation, which leads to the gentle decline in capacity over the initial 200 cycles. In the later cycling period, the exfoliation of active materials causes poor electronic contacts in the film and results in severe capacity fading.

[en] Highlights: • With an increase in bias voltage, the oxidation resistance of the NiCoCrAlYTa coating by arc ion plating significantly decreased although the coating became dense • Ta played a detrimental role on the oxidation behaviour at the latter stage of the oxidation process since it could accelerate the degradation of the protective Al₂O₃ layer. • The degradation of the Al₂O₃ layer could be a gradual evolution process without cracks or spallations. -- Abstract: The NiCoCrAlYTa coatings were prepared on the superalloy K423A by arc ion plating under different bias voltages from -50V to -150V, and the oxidation behaviour of these coatings was investigated at 1050°C for 100 h. The results showed that with an increase in bias voltage, the oxidation resistance of the coating significantly decreased although the coating became denser. Ta played a detrimental role on the oxidation behaviour at the latter stage of the oxidation process. The degradation mechanism of the protective Al₂O₃ layer and the oxidation model of the coating were discussed.